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Survival of the fittest: VO2max, a key predictor of longevity?
Abstract
Cardiorespiratory fitness, as measured by maximal oxygen uptake (VO2max), is related to functional capacity and human performance and has been shown to be a strong and independent predictor of all-cause and disease-specific mortality. The purpose of this review is to emphasize age-related physiological adaptations occurring with regular exercise training, with specific reference to the main organs (lung, heart, skeletal muscles) involved in oxygen delivery and utilization as well as the importance of exercise training for promoting life expectancy in clinically referred populations. As yet, it is not possible to extend the genetically fixed lifespan with regular exercise training, but to give the years more life. This is where physical fitness plays an important role
... [8,9] Cardiorespiratory fitness is arguably the strongest predictor of all-cause mortality secondary to age, with plenty of evidence emphasising its analytical and clinical validity. [10,11,12] The physiological factors that were most often associated with maximum oxygen consumption (VO2max) include stroke volume (SV), cardiac output (CO), maximum heart rate (HRmax), central adiposity and muscular strength. [13] Thus, we believe VO2max could be an appropriate marker of an individual's physical health when testing for functions that perhaps interfere with physical activity. ...
... Besides, cardiac growth and reduced total peripheral resistance led to improved cardiac compliance, potentially enhancing stroke volume. [10,49,50] Few ageing studies revealed over 15% reduction in maximum SV accounted for a 30% lower VO2max in master athletes, reinforcing the relationship. [51] Moreover, CO was reported proportional to VO2 in master athletes [52] , Wagner [53] highlighted the majority of variance in absolute VO2max was attributed to the decline of CO due to the fall in VO2max with ageing being related to a reduced blood flow. ...
... The buildup of norepinephrine enhanced the inotropic effect and caused the contractility of the heart to increase. [10,57] These mechanisms likely result in the association between HRmax and VO2max. ...
This is the first study to examine the relationship between maximal oxygen consumption (VO2max) and a wide range of physiological variables covering central mechanisms, body fat and muscle. Given that using age information to group participants in research is somewhat oversimplistic, with ages typically grouped into arbitrary ranges, it is questioned whether this reflects the stages of ageing and level of body functions. Here, we investigate whether VO2max is a good predictor of physiological functions and, therefore the possibility of grouping participants based on VO2max. Each participant performed a cardiopulmonary exercise test on a cycle ergometer, knee extensor strength test on a custom-built dynamometer and grip strength tested with a handgrip dynamometer. Significant correlations were observed with indices including resting systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MAP), maximal heart rate (HRmax), body percentage of fat and high-density lipoprotein (HDL).
Interestingly, no association was found with resting stroke volume (SV) and cardiac output (CO). Even if HRmax showed the closest relationship with VO2max (r = 0.349, P = 0.025), most of the indexes showed only slight or no association with VO2max, precluding the recognition of physiological functions of any individuals. Hence, our hypothesis was rejected, suggesting VO2max is not a suitable hallmark for grouping participants in studies.
... VO2max is an indicator of the body's ability to supply oxygen to active muscles and is considered a strong predictor of longevity [106,107]. Among male SUD populations aged around 30, VO2max values range from 29 to 36.5 mL·kg −1 ·min −1 , which is below the average for the general population [42,[106][107][108]. ...
... VO2max is an indicator of the body's ability to supply oxygen to active muscles and is considered a strong predictor of longevity [106,107]. Among male SUD populations aged around 30, VO2max values range from 29 to 36.5 mL·kg −1 ·min −1 , which is below the average for the general population [42,[106][107][108]. Physical exercise is key to increasing this variable, with studies reporting its effectiveness in SUD populations [42,108]. ...
Physical exercise has emerged as a promising complementary intervention for individuals with substance use disorders (SUD). This comprehensive review examines the neurobiological, psychological, and social benefits of exercise in improving quality of life (QOL), mental health, sleep quality, craving, physical fitness, and cognitive function among individuals with SUD. Aerobic exercises, particularly those of moderate intensity, demonstrate a consistent efficacy in reducing anxiety, depression, and cravings, while also enhancing cardiovascular health and psychosocial well-being. Strength training and concurrent programs provide additional benefits for muscular and cognitive function, although their effects on mental health are less consistent. Mind–body disciplines like yoga and Tai Chi offer accessible entry points for individuals with low baseline fitness but exhibit variable outcomes, especially in sleep and craving management. High-intensity interval training (HIIT) shows potential for craving reduction and cardiovascular improvements but may pose challenges for individuals with low initial fitness. This review underscores the importance of tailored, well-structured programs that align with participants’ needs and capabilities. Future research should prioritize standardizing protocols, incorporating technological tools, and exploring hybrid intervention models to maximize adherence and therapeutic impact. Physical exercise remains a vital, multifaceted tool in comprehensive SUD rehabilitation strategies.
... Aged-related decreases in aerobic capacity are smaller in highly trained individuals (~0.5% per annum) than those who are moderately trained or sedentary (~1.0% per annum) (Tanaka, 2017;Trappe, 2007). Despite the similar relative decreases in aerobic capacity in trained and sedentary ageing populations, the absolute values of those who are trained remain higher than those who are sedentary (Strasser & Burtscher, 2018;Valenzuela et al., 2020), thus enhancing successful ageing in physically active older individuals. Indeed, research has shown that aerobic capacity has a positive relationship with endurance exercise performance (Midgley et al., 2007), and is related to positive health outcomes and enhanced longevity in older individuals (Strasser & Burtscher, 2018;Valenzuela et al., 2020). ...
... Despite the similar relative decreases in aerobic capacity in trained and sedentary ageing populations, the absolute values of those who are trained remain higher than those who are sedentary (Strasser & Burtscher, 2018;Valenzuela et al., 2020), thus enhancing successful ageing in physically active older individuals. Indeed, research has shown that aerobic capacity has a positive relationship with endurance exercise performance (Midgley et al., 2007), and is related to positive health outcomes and enhanced longevity in older individuals (Strasser & Burtscher, 2018;Valenzuela et al., 2020). For example, every increase of 1 ml.kg.min -1 of VO 2max has been shown to be associated with a 9% reduction in relative risk of all-cause mortality (Laukkanen et al., 2016). ...
... Cardiorespiratory fitness (CRF) is an intrinsic physiological trait that is also associated with longevity [13]. CRF, defined as the ability of the circulatory and respiratory systems to supply oxygen to skeletal muscles during sustained exercise, is routinely measured by maximal oxygen uptake (VO 2 max) during a graded exercise test. ...
... CRF, defined as the ability of the circulatory and respiratory systems to supply oxygen to skeletal muscles during sustained exercise, is routinely measured by maximal oxygen uptake (VO 2 max) during a graded exercise test. CRF is a highly heritable trait in humans [10] and, importantly, inherited high CRF phenotypes mirror the CR-induced phenotypes, including lower adiposity [11], higher cardiometabolic health [12], and greater longevity [13]. As such, a key question in the field is whether CR "phenocopies" the intrinsic high-CRF characteristics via similar, overlapping, or distinct mechanisms. 1 We have been characterizing an established rat model selectively bred from a genetically heterogeneous stock (N:NIH) to generate a high capacity runner (HCR) line and low capacity runner (LCR) line in a manner that maintains genetic heterogeneity [14e16]. ...
Objective
Caloric restriction (CR) is one extrinsic intervention that can improve metabolic health, and it shares many phenotypical parallels with intrinsic high cardiorespiratory fitness (CRF), including reduced adiposity, increased cardiometabolic health, and increased longevity. CRF is a highly heritable trait in humans and has been established in a genetic rat model selectively bred for high (HCR) and low (LCR) CRF, in which the HCR live longer and have reduced body weight compared to LCR. This study addresses whether the inherited high CRF phenotype occurs through similar mechanisms by which CR promotes health and longevity.
Methods
We compared HCR and LCR male rats fed ad libitum (AL) or calorically restricted (CR) for multiple physiological, metabolic, and molecular traits, including running capacity at 2, 8, and 12 months; per-hour metabolic cage activity over daily cycles at 6 and 12 months; and plasma lipidomics, liver and muscle transcriptomics, and body composition after 12 months of treatment.
Results
LCR-CR developed a physiological profile that mirrors the high-CRF phenotype in HCR-AL, including reduced adiposity and increased insulin sensitivity. HCR show higher spontaneous activity than LCR. Temporal modeling of hourly energy expenditure (EE) dynamics during the day, adjusted for body weight and hourly activity levels, suggest that CR has an EE-suppressing effect, and high-CRF has an EE-enhancing effect. Pathway analysis of gene transcripts indicates that HCR and LCR both show a response to CR that is similar in the muscle and different in the liver.
Conclusions
CR provides LCR a health-associated positive effect on physiological parameters that strongly resemble HCR. Analysis of whole-body EE and transcriptomics suggests that HCR and LCR show line-dependent responses to CR that may be accreditable to difference in genetic makeup. The results do not preclude the possibility that CRF and CR pathways may converge.
... For the development of effective interventions aiming to reduce cardiovascular risk factors, it is crucial to understand the various factors contributing to CRF and to identify high-risk population groups. Although it is well-documented that fitness levels tend to decline with increasing age over the lifespan (Shephard 2009;Fiedler et al., Under Review;Tanaka and Seals 2003;Strasser and Burtscher 2018), other factors may also play significant roles in influencing CRF. In addition to genetic predispositions, physical exercise (PE) and physical activity (PA) are recognized as key elements in enhancing fitness levels. ...
Cardiorespiratory fitness (CRF) is considered as a main indicator of cardiovascular health and is associated with a reduced risk of noncommunicable diseases. The objective is to explore the potential behavioral, interpersonal, socioeconomic, and anthropometric factors associated with a submaximal measure for CRF among adolescents and adults in Germany. Data were drawn from a population‐based nationwide cross‐sectional study, involving 2886 male and 3034 female participants aged 14–64 who were part of the German Health Interview and Examination Survey (2008–2011) and the Examination Survey for Children and Adolescents (2014–2017). Participants completed a submaximal cycle ergometer test to determine the relative power at the individual anaerobic lactate threshold (pLT2) (W/kg). Multivariable survey‐weighted mixed linear regression analyses were conducted to assess the associations of potential correlates with pLT2. Among both sexes, being involved in physical exercise (PE) and activity (PA) and having a tertiary education was associated with hana higher pLT2, whereas currently smoking and classified as overweight or obese was associated with a lower pLT2. Among females being single and among males, a higher fruit consumption was associated with a higher pLT2. A lower pLT2 was associated with a higher waist circumference and a high junk food intake in females and being a former smoker and being single in males. Overall, PE and nonsmoking are the most important determinants for pLT2; therefore, policies and interventions targeting those factors would be important for preventing noncommunicable diseases. Overall, these findings can offer valuable insights for customizing prevention strategies to meet the specific needs of different subgroups.
... The relevance of this variable underscores the practical importance of the improvement in CRF observed in the YG. CRF predicts population survival-independent of all-cause mortality (Strasser & Burtscher, 2018)-and is a prognostic and diagnostic assessment tool across various pathologies (deJong, 2011). Given these considerations, increasing CRF becomes a fundamental goal in designing and implementing physical activity programs that improve health and promote an active lifestyle within the population (Milanović et al., 2015). ...
Physical inactivity and sedentary behaviour are significant risk factors for diseases such as cardiovascular disease, cancer, and mental health disorders. Kundalini Yoga (KY) is recognised for its potential to improve physical and mental health. Objective: To evaluate the effects of a 6-week KY program on cardiorespiratory fitness (CRF) and health-related quality of life (HRQoL) in physically inactive university students. Methodology: A randomised controlled trial with a parallel-group, double-blind design included 26 university students divided into a Yoga group (YG, n=13) and a control group (CG, n=13). The YG completed twelve KY sessions over six weeks (two per week). Assessments included peak oxygen consumption (VO₂peak) and the SF-36 HRQoL questionnaire. A repeated measures analysis assessed the time×group interaction effect with post-hoc analysis (alpha= .05). Results: Significant improvements were observed in YG for relative (∆=3.21; d=0.66) and absolute (∆=173.07; d=0.40) VO₂peak, and maximal effort test performance (∆=12.31; d=0.34). YG showed significant enhancements in the general health dimension of HRQoL (∆=20.0), physical function (∆=5.0), and overall behaviour (∆=12.9), while CG improved only in physical function (∆=5.0). Discussion The findings suggest that KY provides greater improvements in CRF and comparable enhancements in HRQoL compared to other yoga styles, even within a shorter intervention period. KY appears effective as a health-promoting intervention. Conclusions: Twelve sessions of KY over 6 weeks significantly improved CRF and HRQoL in physically inactive university students. A KY program is recommended for physically inactive individuals who wish to adopt an active lifestyle and improve their CRF and HRQoL.
... Such low VO 2peak is below the threshold required for full and independent living and thus could be used for timely referral to prehabilitation. [49][50][51] The importance of efficiency in LT evaluation cannot be overemphasized, as this can impact patient mortality. In this regard, CPX constitutes an efficient test that is able to provide ischemic risk estimation, a dynamic assessment of cardiopulmonary function, and a surrogate of physical decline to determine the need for prehabilitation. ...
Background
Cardiovascular disease and physical decline are prevalent and associated with morbidity/mortality in liver transplant (LT) patients. Cardiopulmonary exercise testing (CPX) provides comprehensive cardiopulmonary and exercise response assessments. We investigated cardiorespiratory fitness (CRF) and cardiac stress generated during CPX in LT candidates.
Methods
LT candidates at 2 centers underwent CPX. Standard-of-care cardiac stress testing (dobutamine stress echocardiography, DSE) results were recorded. Physical function was assessed with liver frailty index and 6-min walk test. CPX/DSE double products were calculated to quantify cardiac stress. To better study the association of CPX-derived metrics with physical function, the cohort was divided into 2 groups based on 6-min walk test median (372 m).
Results
Fifty-four participants (62 ± 8 y; 65% men, Model for End-Stage Liver Disease-Na 14 [10–18]) underwent CPX. Peak oxygen consumption was 14.1 mL/kg/min for an anerobic threshold of 10.2 mL/kg/min, with further CRF decline in the lower 6MWT cohort despite lack of liver frailty index-frailty in 90%. DSE was nondiagnostic in 18% versus 4% of CPX ( P = 0.058). All CPX were negative for ischemia. A double product of ≥25 000 was observed in 32% of CPX and 11% of DSE ( P = 0.020). Respiratory function testing was normal. No patient presented major cardiovascular events at 30 d post-LT.
Conclusions
CPX provided efficient and effective combined cardiopulmonary risk and frailty assessments of LT candidates in a 1-stop test. The CRF was found to be very low despite preserved physical function or lack of frailty.
... It is the best predictor of future cardiovascular health and related diseases. [3] Therefore, the assessment of VO 2max is essential in the evaluation of the health of the population and the estimation of future risk. However, the measurement of VO 2max requires sophisticated equipment and trained personnel. ...
BACKGROUND
Maximum oxygen consumption (VO 2max ), an essential indicator of integrated function of the cardiovascular, respiratory, and muscular systems, is an excellent predictor of all-cause morbidity and mortality. Direct measurement is a sophisticated procedure which for some individuals is difficult to perform. The use of international formulae leads to overestimation or underestimation of values. Therefore, the present study aimed to generate a best-fit VO2max prediction formula for young Saudi females.
MATERIALS AND METHODS
One hundred and two randomly selected young healthy Saudi females (19–25 years) with normal body mass index (18.5–24.99 kg m ⁻² ) and sedentary lifestyle underwent maximum cardiopulmonary exercise testing on cycle ergometer when using breath-by-breath analyzing system. Hemodynamic and ventilatory parameters were assessed before and during the maximum exercise. Significantly correlated exercise and nonexercise parameters enterd in multiple linear regression analysis to find the best-fit model, and used to generate a VO 2max prediction formula.
RESULTS
The mean measured VO 2max was 1449.1 ± 233.92 ml min ⁻¹ . The VO 2max prediction formula was 1304.193 ± 17.902 × body weight + 43.857 × time until exhaustion − 6.83 × maximum heart rate. The mean calculated VO 2max was 1449.14 ± 143.97 ml min ⁻¹ . No statistically significant difference was observed between the measured and calculated VO 2max . The Bland–Altman test for the limit of agreement was performed and showed good agreement between the two values with a minute proportional bias. The standard error of the estimate was 156.34, which is approximately 10.6% of the mean measured VO 2max . Reliability analysis yielded a Cronbach’s alpha of 0.709.
CONCLUSION
This study presents a reliable and valid VO 2max prediction formula for young Saudi females. This nationally generated formula is far more representative of the VO 2max value than international formulae. We recommend the implementation of this formula and an investigation of its validity in other Saudi population groups.
... However, research indicates that less than 60% of women with PCOS engage in regular physical activity [5] and more than 25% are sedentary [6]. Fitness (the sum attributes of cardiorespiratory capacity, muscular strength and endurance, and flexibility), is a marker of physical and mental health and people who are fit have lower mortality from any cause as compared to those who are not fit [7]. To date, there are no research studies about fitness as an indicator of PCOS clinical features and health risk. ...
Background
Fitness is a marker of physiological and mental health. The purpose of this pilot study was to assess the feasibility of processes to recruit women with polycystic ovary syndrome (PCOS) during the Covid pandemic and collect their health and fitness data. Additionally, the data was used to explore possible associations between anthropometrics, PCOS biomarkers, health-related quality-of-life (HRQoL), and depressive symptoms with that of fitness and self-reported physical activity levels among women with PCOS.
Methods
A convenience sample of women with PCOS (n = 15) were recruited via flyers and the snowball method. Participants completed surveys, anthropometrics, a dual energy x-ray absorptiometry scan, blood work, and a fitness assessment. Data were statistically analyzed using Spearman correlations.
Results
Feasibility measures of recruitment and retention rates were 83% and 100%, respectively. Fidelity measurement for process averaged 97%. Participants (age 25.9 (± 6.2), mostly White (80%), single (60%), and employed full-time (67%)) were categorized as obese (body mass index (BMI) 32.2 kg/m² ± 8.3, percent bodyfat 41.1% ± 8.1) with ≤1 comorbidity. Most participants were not regularly physically active and had high free testosterone levels (7.6 pg/mL ± 4.3), elevated high-density lipoprotein (63.2 mg/dL ± 12.9), fair cardiovascular capacity, and below average muscular strength/endurance. The following statistically significant and strong associations were found: (1) VO2 max with percent bodyfat (–0.59; p = 0.02), sex hormone binding globulin (0.73; p = 0.00), HRQoL (0.72; p = 0.00), and depressive symptoms (–0.67; p = 0.00), (2) abdominal strength with BMI (–0.66; p = 0.01) and high density lipoprotein (HDL) (0.59; p = 0.02), (3) physical activity level with percent bodyfat (–0.72; p = 0.00), and (4) resistance training with low density lipoprotein (LDL) (–0.52; p = 0.05).
Conclusions
Collecting health and fitness data from women with PCOS is a feasible research approach. Randomized controlled trials in which health and fitness data are collected from women with PCOS are needed to confirm possible associations between fitness and PCOS clinical features and is in the planning process.
... This is to equate the characteristics of athletes so that confounding variables during statistical analysis can be suppressed. According to the research, physical activity above 1000 METS is in the moderate to high category (Strasser & Burtscher, 2018). Apart from physical activity, the researchers also conducted matching with BMI-for-age. ...
Introduction: Despite the critical function of a nutritionist, only a few sports training centres for students in Indonesia have one. This study aimed to determine the effect of the nutrition care process (NCP) on athletes’ nutritional status and aerobic capacity performance. Methods: This cohort study was conducted in 2022 (May–August) in four training centres (TC) in Indonesia. Subjects were athletes who have been dwelling in TC for at least three months, excluding those absent for >14 days due to a competition or other commitments during the data collection period. NCP included the assistance of trained sports nutritionists. In total, 114 athletes participated in this study: 90 strength athletes and 24 endurance athletes. The participants were aged 14-19 years old with approximately (mean+SD) 6+2.5 years of experience in specific sports. Results: After three months of NCP, knowledge of nutrition (p=0.013), body fat composition (p<0.001), skinfold thickness scores (p<0.001), and performance (p<0.001) of athletes significantly improved. In spite of good intakes of protein and fat, none of the intakes showed significant changes (p>0.05). Furthermore, improved knowledge of sports nutrition and exercise science had a positive impact on dormitory meal choices. Conclusion: Overall, three months of NCP had a significant effect on athletes’ knowledge of nutrition, body fat composition, skinfold thickness, and also VO2Max.
... It is the gold standard for evaluating aerobic capacity/cardiorespiratory tness and can be objectively measured during a graded cardiopulmonary exercise test with respiratory gas exchange [39]. Therefore, VO 2max has been linked as a potential predictor of future survival and will be used as an indicator of cardiorespiratory tness in these investigations [40]. For these studies, we will use a validated model of moderate aerobic exercise in which mice will run on a treadmill at 50-75% of their maximum O 2 consumption. ...
Background:Triple-negative breast cancer constitutes approximately 15-20% of breast cancers and continues to be challenging to treat despite significant therapeutic advances. Epidemiological evidence suggests psychological stress correlates with decreased survival rates, while physical activity is presumed to improve survival rates of breast cancer patients. These correlations lead us to inquire whether aerobic exercise could improve cancer outcomes despite the psychological stress associated with a cancer diagnosis. In part, these parallels may be mediated by alterations in the anti-tumor immune responses meditated by neuroendocrine changes experienced during stress, which are believed to affect cancer progression. To address this, we used a syngenetic mouse model of breast cancer to study the impact of stressors.
Objective: This study investigated the effects of psychological stress and/or physical activity on tumor growth and cancer immunity in mice with murine triple-negative breast cancer.
Methods: We used female BALB/c mice subcutaneously injected with murine EMT6 breast carcinoma cells. Mice were assigned to treatment groups: moderate aerobic exercise, unpredictable chronic mild stress, a combination of exercise and chronic stress, or no physical/psychological stressor.
Results: Mice were assessed for tumor growth and immunological changes within the primary tumors. Our studies showed both aerobic exercise and chronic mild stress resulted in larger tumors, while non-stressed/non-exercised controls had consistently smaller tumors. We found the smaller tumors exhibited higher presence of T helper and cytotoxic T cells. Additionally, we demonstrated that exercise improves the proliferative and suppressive functions of T helper and T regulatory cells, respectively, whether with or without chronic stress. Interestingly, the anti-tumor cytotoxic T cell function was enhanced in exercised mice, but these functional benefits were not observed when chronic stress was added. Notably, the decreased cytotoxicity results are correlated with increased PD-1 expression.
Conclusions: Neither physical activity nor psychological stress reduced tumor growth once established; instead, they significantly increased tumor progression. Exercise did not appear to mitigate the impact of psychological stress on tumor growth or combat the negative impacts on anti-tumor immunity. However, our findings did suggest different stressors impact key anti-tumor immune cell numbers and functions that will need to be considered when developing treatment plans.
... However, aerobic training yielded a non-significant result for CRF using the treadmill ergometer while combined aerobic and resistance training showed marked improvement in CRF. These contradictory findings using the treadmill versus cycle ergometer can possibly indicate some heterogeneity and methodological bias in assessing the maximal oxygen uptake ( VO max , key indicator of functional performance [46], since low VO max indicates higher risk of mortality in advanced stages of BC [47] ) using the two techniques. While both cycle and treadmill ergometer are known tools for effective assessment of CRF, it should be noted that since they focus on assessing VO max , they are more likely a better choice for assessing aerobic training compared with resistance training. ...
Background
The effects of exercise in patients with breast cancer (BC), has shown some profit, but consistency and magnitude of benefit remains unclear. We aimed to conduct a meta-analysis to assess the benefits of varying types of exercises in patients with BC.
Methods
Literature search was conducted across five electronic databases (MEDLINE, Web of Science, Scopus, Google Scholar and Cochrane) from 1st January 2000 through 19th January 2024. Randomized controlled trials (RCTs) assessing the impact of different types of exercise on outcomes related to fitness and quality of life (QOL) in patients with BC were considered for inclusion. Outcomes of interest included cardiorespiratory fitness (CRF), health-related quality of life (HRQOL), muscle strength, fatigue and physical function. Evaluations were reported as mean differences (MDs) with 95% confidence intervals (CIs) and pooled using random effects model. A p value < 0.05 was considered significant.
Results
Thirty-one relevant articles were included in the final analysis. Exercise intervention did not significantly improved the CRF in patients with BC when compared with control according to treadmill ergometer scale (MD: 4.96; 95%Cl [-2.79, 12.70]; P = 0.21), however exercise significantly improved CRF according to cycle ergometer scales (MD 2.07; 95% Cl [1.03, 3.11]; P = 0.0001). Physical function was significantly improved as well in exercise group reported by 6-MWT scale (MD 80.72; 95% Cl [55.67, 105.77]; P < 0.00001). However, exercise did not significantly improve muscle strength assessed using the hand grip dynamometer (MD 0.55; 95% CI [-1.61, 2.71]; P = 0.62), and fatigue assessed using the MFI-20 (MD -0.09; 95% CI [-5.92, 5.74]; P = 0.98) and Revised Piper scales (MD -0.26; 95% CI [-1.06, 0.55] P = 0.53). Interestingly, exercise was found to improve HRQOL when assessed using the FACT-B scale (MD 8.57; 95% CI [4.53, 12.61]; P < 0.0001) but no significant improvements were noted with the EORTIC QLQ-C30 scale (MD 1.98; 95% CI [-1.43, 5.40]; P = 0.25).
Conclusion
Overall exercise significantly improves the HRQOL, CRF and physical function in patients with BC. HRQOL was improved with all exercise types but the effects on CRF vary with cycle versus treadmill ergometer. Exercise failed to improve fatigue-related symptoms and muscle strength. Large RCTs are required to evaluate the effects of exercise in patients with BC in more detail.
... The importance of the thalamus has been proven also when analyzing physical and cognitive fatigue separately [13]. Interestingly, a higher aerobic capacity, measured by maximal oxygen uptake, which represents individual exercise tolerance [14], has been also found to be associated with lower levels of fatigue in pwMS [15]. Several underlying mechanisms have been proposed to explain these beneficial effects of higher aerobic capacity on fatigue perception, among which the neuroprotective effect on CNS [16], normalization of hypothalamic-pituitary-adrenal axis imbalances [17,18] and anti-inflammatory effect [19]. ...
Background
Fatigue is frequent in people with multiple sclerosis (pwMS) impacting physical and cognitive functions. Lower aerobic capacity and regional thalamic volume may be involved in the pathophysiology of fatigue in pwMS.
Objectives
To identify associations between thalamic nuclei volumes, aerobic capacity and fatigue and to investigate whether the influence of aerobic capacity on fatigue in pwMS is mediated by thalamic integrity.
Methods
Eighty-three pwMS underwent a clinical evaluation with assessment of fatigue (Modified Fatigue Impact Scale [MFIS]), including physical (pMFIS) and cognitive (cMFIS) components, and peak of oxygen uptake (VO2peak). PwMS and 63 sex- and age-matched healthy controls (HC) underwent a 3 T brain MRI to quantify volume of the whole thalamus and its nuclei.
Results
Compared to HC, pwMS showed higher global MFIS, pMFIS and cMFIS scores, and lower VO2peak and thalamic volumes (p < 0.001). In pwMS, higher VO2peak was significantly associated with lower MFIS and pMFIS scores (r value = − 0.326 and − 0.356; pFDR ≤ 0.046) and higher laterodorsal thalamic nucleus (Dor) cluster volume (r value = 0.300; pFDR = 0.047). Moreover, lower Dor thalamic cluster volume was significantly associated with higher MFIS, pMFIS and cMFIS scores (r value range = − 0.305; − 0.293; pFDR ≤ 0.049). The volume of Dor thalamic cluster partially mediated the positive effects of VO2peak on both MFIS and cMFIS, with relative indirect effects of 21% and 32% respectively. No mediation was found for pMFIS.
Conclusions
Higher VO2peak is associated with lower fatigue in pwMS, likely acting on Dor thalamic cluster volume integrity. Such an effect might be different according to the type of fatigue (cognitive or physical).
... A 1 ml/kg/min increase in VO2max is linked to a 9% reduction in all-cause mortality in middle-aged men, indicating a correlation with longer life expectancy. [7] Mini-trampoline bouncing is more effective than traditional running, resulting in a 7.82% increase in VO2max for rebounding exercise compared to only 2.34% in running. [8] However, in comparing mini-trampoline training to treadmill running, the latter showed a slight advantage, with a significant difference observed in medium-intensity training but no significant difference in low-and high-intensity training. ...
Introduction and Objective: In the modern era, where non-communicable diseases account for 74% of deaths, physical activity plays a crucial role in reducing mortality rates, particularly from cardiovascular causes. This article aims to assess the benefits and risks of trampoline bouncing as an exercise modality. State of Knowledge: Scientific evidence predominantly focuses on rebounding-related injuries, overshadowing the relatively underexplored benefits of trampolining. Cardiovascular advantages, including increased VO2max, are notable, with mini-trampoline exercise proving more effective than traditional running. Trampolining exhibits the potential to reduce BMI and weight, impacting cardiovascular risk factors while contributing to bone strength and mental well-being. Positive outcomes are suggested for specific groups, such as Parkinson's patients and children with disabilities. Summary: Trampoline rebounding, particularly with mini-trampolines, presents an enjoyable exercise form with significant health benefits, encompassing enhanced cardiovascular endurance, improved balance, and positive effects on bone structure and mental well-being. Despite prevalent injuries associated with trampoline use, the article highlights effective preventive measures. In conclusion, trampoline bouncing holds promise as a valuable component of a healthy lifestyle, provided adequate precautions are taken to mitigate associated risks.
... Cardiorespiratory fitness (CRF) is strongly associated with reduced risk of obesity and the prevention of numerous non-communicable diseases. CRF is therefore considered an important predictor of morbidity and mortality [1][2][3]. Most commonly, aerobic capacity is expressed as maximum rate of oxygen uptake (VO 2max ). ...
Endurance performance tests directly measuring cardiorespiratory fitness are complex, but field tests indirectly assessing maximum oxygen uptake (VO2max) are an alternative. This study aimed to validate the 6-minute run test in adults, comparing it to the established shuttle run test, and to create reference equations. The cross-over design involved healthy adults aged 18–65 undertaking both tests, separated by a two-hour interval. The 6-minute run test required participants to run around a volleyball court for six minutes, aiming to maximize distance covered. The shuttle run involved participants covering 20 meters in defined time intervals at increasing speeds. Parameters measured included 6-minute run test distance, heart rates, calculated maximum oxygen uptake during the shuttle run, and total shuttle count. The study enrolled 250 participants (134 men and 116 women). Men averaged 1195.7 m (SD=161.4), while women averaged 1051.2 m (SD=148.0) in six minutes. The strongest correlation was found between the distance covered in the 6-minute run test and the total shuttle count (r=0.91, p<0.001). Two predictive models for 6-minute run test distance were developed and normative values for different sex-specific age clusters were established. The study showed that the 6-minute run test is valid as a practical endurance test for adults aged 18–65.
... This is because cardiorespiratory fitness is related to functional capacity and has been shown to be a strong and independent predictor of all-cause and disease-specific mortality. This association is so strong that cardiorespiratory fitness is considered one of the key predictors of longevity [45]. The present programme's improvements in cardiorespiratory are supported by those of O'Brien et al. [33] whose 6-month, thrice-weekly, 90 min multimodal (aerobic, strength, balance, and flexibility training) programme using middle-aged participants was found to have increased their mean peak oxygen consumption (VO2peak) by a median of 0.56 mL.kg −1 .min ...
Non-communicable diseases (NCDs) are the leading cause of death globally, particularly impacting low-and middle-income countries and rural dwellers. Therefore, this programme aimed to investigate if a community-based mind-body PA programme implemented in a low-resource setting could improve health-related physical fitness outcomes. Black overweight or obese adult women (25 ± 4.7 years) with a body mass index (BMI) >25 kg.m −2 recruited from a rural settlement in South Africa with manifest risk factors for multimorbidity were assigned to a 10-week waiting-to-treat non-exercising control group (n = 65) or a community-based mind-body programme (n = 60) consisting of 45-60 min, thrice-weekly Tae-Bo. The intervention resulted in significant (p ≤ 0.05) improvements in body weight (p = 0.043), BMI (p = 0.037), and waist (p = 0.031) and hip circumferences (p = 0.040). Flexibility was found to be significantly increased at mid-and post-programme (p = 0.033 and p = 0.025, respectively) as was static balance (mid: p = 0.022; post: p = 0.019), hand grip strength (mid: p = 0.034; post: p = 0.029), sit-up performance (mid: p = 0.021; post: p = 0.018), and cardiorespiratory endurance (mid: p = 0.017; post: p = 0.011). No significant change was found in sum of skinfolds following the programme (p = 0.057). Such a community-based mind-body programme presents an opportunity to level health inequalities and positively improve health-related physical fitness in low-resource communities irrespective of the underlying barriers to participation .
... The result shows a mean increase of 12.9% in VO 2 peak with a clinical benefit of all-cause and disease-specific mortality. 6 Regarding 6 MWT, the field walk test documented a mean of 38.69% change. The increased 6 MWT distance postrehabilitation has been established objectively, as evidenced by the significant outcome. ...
Patients with post-acute COVID-19 symptoms (PACS) can present with significant sequela due to the complex systemic effects of COVID-19 infection. Most affected patients have persistent symptoms for 3-12 months after recovery from the acute phase of COVID-19. Dyspnea affecting activities of daily living is one of the most challenging symptoms and has led to an influx of pulmonary rehabilitation (PR) demand. Here we report the outcome of nine subjects with PACS who underwent 24 sessions of supervised pulmonary telerehabilitation. An improvised telerehabilitation PR was formulated to accommodate home confinement during the pandemic. Exercise capacity and pulmonary function were assessed using a cardiopulmonary exercise test, pulmonary function test, and St. George Respiratory Questionnaire (SGRQ). The clinical outcome shows improved exercise capacity on the 6-minute walk test for all patients, and most had improvement in VO2 peak and SGRQ. Seven patients improved in forced vital capacity and six in forced expiratory volume. PR is a comprehensive intervention for patients with chronic obstructive disease aimed at alleviating pulmonary symptoms and improving functional capacity. In this case series, we report its usefulness in patients with PACS and its feasibility when delivered as a supervised telerehabilitation program. Further support for the effectiveness of PR patients with PACS is mandated.
... Although VȮ 2 max is measured in liters per minute, it can be expressed as a weight-adjusted rate (ml·kg −1 ·min −1 ), which is more adequate to compare individuals with different body masses [7]. This measure is also influenced by body composition, which becomes worse with increasing fat mass and decreasing lean mass during the aging process [8]. ...
Performance in endurance sports decreases with aging, which has been primarily attributed to cardiovascular and musculoskeletal aging; however, there is still no clear information on the factors that are most affected by aging. The aim of this study was to compare two groups of runners (< 50 and > 50 years of age) according to their absolute, weight-adjusted maximal oxygen uptake (V̇O2max), lower limb lean mass-adjusted V̇O2max, ventilatory threshold, and respiratory compensation point (RCP). A total of 78 male recreational long-distance runners were divided into Group 1 (38.12 ± 6.87 years) and Group 2 (57.55 ± 6.14 years). Participants were evaluated for body composition, V̇O2max, VT, and RCP. Group 1 showed higher absolute and body mass-adjusted V̇O2max (4.60 ± 0.57 l·min-1 and 61.95 ± 8.25 ml·kg-1·min-1, respectively) than Group 2 (3.77 ± 0.56 l·min-1 and 51.50 ± 10.22 ml·kg-1·min-1, respectively), indicating a significant difference (p < 0.001, d = - 1.46 and p < 0.001, d = - 1.16). Correspondingly, Group 1 showed a significantly higher lower limb lean mass-adjusted V̇O2max (251.72 ± 29.60 ml·kgLM-1·min-1) than Group 2 (226.36 ± 43.94 ml·kgLM-1·min-1) (p = 0.008, d = - 0.71). VT (%V̇O2max) (p = 0.19, d = 0.19) and RCP (%V̇O2max) (p = 0.24, d = 0.22) did not differ between the groups. These findings suggest that both variables that are limited by central or peripheral conditions are negatively affected by aging, but the magnitude of the effect is higher in variables limited by central conditions. These results contribute to our understanding of how aging affects master runners.
... [12][13][14] Training strategies that are most effective in enhancing VȮ 2max are clinically relevant, as VȮ 2max is predictive of long-term survival. 15,16 However, substantially less is known regarding the effects of HIIT in cardiac rehabilitation on submaximal variables of exercise capacity. These variables are relevant, as their measurement does not rely on maximal effort and motivation of patients, and allow conclusions about the physiological and metabolic strain during exercise at a given intensity 17 and can be used to prescribe exercise intensities. ...
Here, we present evidence that replacement of half of the usually prescribed continuous exercise training sessions in cardiac rehabilitation with high-intensity interval training sessions affects these trajectories. High-intensity interval training shifts the nadirs of ventilatory equivalents for O2 and CO2 and the subsequent rise to load termination in cardiopulmonary exercise tests toward higher wattages. Surprisingly, however, the difference between training types does not show up in the trajectories of blood lactate concentrations, although they are thought to be based, at least in part, at least in part, on common physiological mechanisms. Thus, cardiopulmonary exercise tests (CPET) allow to detect adaptations to exercise training that are not detectable by measuring blood lactate concentrations. This underlines their importance in cardiac rehabilitation to detect training responses independent of maximally achieved values.
In addition, we present a novel statistical approach of analyzing CPET and BLa data for scientific studies. In contrast to many previous studies, it does not rely on the determination of thresholds. The underlying idea was to circumvent the arbitrary application of any of the multiple (lactate) threshold concepts, which, as pointed out by Poole et al. (Poole DC, Rossiter HB, Brooks GA, Gladden LB. The anaerobic threshold: 50+ years of controversy. The Journal of physiology. 2021;599(3):737-67), “... attempt to describe a curve with a single data point” and therefore, in our view, constitute practical, yet overly simplistic summary measures. Instead, we statistically modelled the entire shape of the trajectories defining the relationship between both blood lactate concentrations and CPET parameters with power output. This allowed us to estimate and visualize how the entire curves changed due to training and allows to estimate group difference for any relative intensity.
... Most patients with NASH have a poor or very poor fitness level, independent of age, body mass index (BMI), and sex [11]. Cardiorespiratory fitness is predictive of mortality in the general population and in those with chronic disease, including NAFLD [12][13][14][15]. The HUNT study found all-cause mortality was increased 52% in NAFLD patients with low cardiorespiratory fitness compared to participants with high cardiorespiratory fitness [15]. ...
Background & Aims
Cardiorespiratory fitness and liver fibrosis are independently associated with poor outcomes in patients with nonalcoholic steatohepatitis (NASH), however, conflicting reports exist about their relationship. We aimed to better characterize the relationship between cardiorespiratory fitness and liver histology in a cross-sectional study of patients with biopsy-proven NASH.
Methods
Participants aged 18–75 years completed VO2peak fitness assessment using symptom-limited graded exercise testing. Participants were compared by liver fibrosis stage and NAFLD Activity Score (NAS). Multivariable models were constructed to assess factors related to relative VO2peak, including liver fibrosis and NAS.
Results
Thirty-five participants with mean age 48 ± 12 years and body mass index 33.5 ± 7.6 kg/m² were enrolled. Seventy-four percent of participants were female and 49% had diabetes. A dose-dependent relationship was found between relative VO2peak and liver fibrosis. Relative VO2peak was significantly lower in participants with advanced fibrosis (F3 disease- 15.7 ± 5.3 vs. ≤ F2 disease- 20.7 ± 5.9 mL/kg/min, p = 0.027). NAS > 5 was also associated with lower relative VO2peak (22.6 ± 5.7 vs. 16.5 ± 5.1 mL/kg/min, p = 0.012) compared to NAS ≤ 5. With multivariable modeling, advanced fibrosis remained independently predictive of relative VO2peak while NAS trended towards significance.
Discussion and Conclusions
Advanced liver fibrosis is independently associated with cardiorespiratory fitness in patients with NASH. This may explain the incremental increase in mortality as liver fibrosis stage increases. Further research is needed to determine if exercise training can improve cardiorespiratory fitness across multiple stages of liver fibrosis and directly reduce morbidity and mortality in patients with NASH.
... In the current state, most molecular clocks are inferior to functional parameters to predict morbidity and mortality in humans (Fig. 4). Endurance and cardiovascular function (for exampleV O 2 max (Strasser & Burtscher, 2018), maximal endurance (Kodama et al., 2009) or daily steps (Paluch et al., 2022)), skeletal muscle function (for example muscle and grip strength (Sayer & Kirkwood, 2015), muscle power (Losa-Reyna et al., 2022) or muscle mass (Liu et al., 2022)) and neuromuscular function (for example gait speed (White et al., 2013)) all show strong prospective correlation with health. Importantly, these parameters represent at least part of the main decline in functional capacity with age that strongly contributes to loss of independence, hospitalization and admission to nursing homes (Nwagwu et al., 2020). ...
Ageing is a biological process that is linked to a functional decline, ultimately resulting in death. Large interindividual differences exist in terms of life‐ and healthspan, representing life expectancy and the number of years spent in the absence of major diseases, respectively. The genetic and molecular mechanisms that are involved in the regulation of the ageing process, and those that render age the main risk factor for many diseases are still poorly understood. Nevertheless, a growing number of compounds have been put forward to affect this process. However, for scientists and laypeople alike, it is difficult to separate fact from fiction, and hype from hope. In this review, we discuss the currently pursued pharmacological anti‐ageing approaches. These are compared to non‐pharmacological interventions, some of which confer powerful effects on health and well‐being, in particular an active lifestyle and exercise. Moreover, functional parameters and biological clocks as well as other molecular marks are compared in terms of predictive power of morbidity and mortality. Then, conceptual aspects and roadblocks in the development of anti‐ageing drugs are outlined. Finally, an overview on current and future strategies to mitigate age‐related pathologies and the extension of life‐ and healthspan is provided. image
... Heart rate (HR, Polar S810i, Polar Electro), maximum oxygen uptake (VȮ 2 max, ZAN 600, ZAN-Messgeräte, Oberthulba, Germany) and maximal power output [W] were recorded. The VȮ 2 max reflects the cardiovascular capacity of a defined person 19 and was, therefore, measured to detect potential changes in cardiovascular capacities of the subject between pre and post the respective training interventions. ...
Mechanosensors control muscle integrity as demonstrated in mice. However, no information is available in human muscle about the distribution of mechanosensors and their adaptations to mechanical loading and environmental conditions (hypoxia). Here, we hypothesized that mechanosensors show fiber‐type‐specific distributions and that loading and environmental conditions specifically regulate mechanosensors. We randomly subjected 28 healthy males to one of the following groups (n = 7 each) consisting of nine loading sessions within 3 weeks: normoxia moderate (NM), normoxia intensive (NI), hypoxia moderate (HM), and hypoxia intensive (HI). We took six biopsies: pre (T0), 4 h (T1), and 24 h (T2) after the third as well as 4 h (T3), 24 h (T4), and 72 h (T5) after the ninth training session. We analyzed subjects' maximal oxygen consumption (V̇O2max), maximal power output (Pmax), muscle fiber types and cross‐sectional areas (CSA), fiber‐type‐specific integrin‐linked kinase (ILK) localizations as well as ILK, vinculin and talin protein and gene expressions in dependence on loading and environmental conditions. V̇O2max increased upon NM and HM, Pmax upon all interventions. Fiber types did not change, whereas CSA increased upon NI and HI, but decreased upon HM. ILK showed a type 2‐specific fiber type localization. ILK, vinculin, and talin protein and gene expressions differed depending on loading and environmental conditions. Our data demonstrate that mechanosensors show fiber type‐specific distributions and that exercise intensities rather than environmental variables influence their profiles in human muscles. These data are the first of their kind in human muscle and indicate that mechanosensors manage the mechanosensing at a fiber‐type‐specific resolution and that the intensity of mechanical stimulation has a major impact.
... Good CRF protects people's health by reducing the development of noncommunicable diseases and decreasing associated risk factors (Tikkanen et al., 2018). In the cardiovascular system, it reduces cardiac stiffness, contributing to better blood distribution (Howden et al., 2018), which is associated with a lower incidence of heart failure (Kokkinos et al., 2019), in addition to maximizing mitochondrial respiration and increasing the eddectivity of blood distribution in the vascular system (Strasser & Burtscher, 2018). Furthermore, good CRF is directly related to the amount of time (minutes) spent in weekly physical activities/exercise. ...
Objective: To associate and compare the level of physical activity with cardiovascular health (CVH), quality of life, cardiorespiratory fitness, anthropometric variables and workload of active and sedentary women working in a university environment. Methods: Cross-sectional study, carried out with employees of a higher education institution. The sample was for convenience and 51 healthy adult women participated. Seven metrics were evaluated for CVH, using the international physical activity questionnaire and the Mediterranean diet questionnaire. Quality of life was assessed using the Short Form-36 instrument and cardiorespiratory fitness using the shuttle run test. The Student-t test and Mann-Whitney U test were used to analyze the data, and a multiple linear regression was performed with data adjusted for age and the climacteric period. Results: Active women had lower values for waist-hip ratio (WHR) (p=0.001) and diastolic blood pressure (DBP) (p<0.001), and higher results for maximal oxygen consumption (VO2max) (p<0.001), CVH score (p<0.001), functional capacity (p=0.004), and general health (p=0.009). There was a direct relationship with the CVH score (p= 0.018) and VO2max (p= 0.012), and an inverse relationship for workload (p=0.013). Conclusion: The level of physical activity contributes to lower values of risk factors for cardiovascular diseases (WHR and DBP) and higher values of VO2max, SCV scores and quality of life in active women.
... Low cardiorespiratory fitness (CRF) quantified as low maximal oxygen uptake (VO2max) is one of the most important risk factors for CVD and premature death, and suggested to be a stronger predictor of morbidity and mortality than established CVD risk factors like obesity, diabetes, smoking, and hypercholesterolemia (2). VO2max is also shown to a be strong and independent predictor of allcause and diseases-specific mortality (3). Low VO2max is shown to increase risk of dementia, cancer, and other lifestyle-related diseases (4,5). ...
Funding Acknowledgements
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Central Norway Regional Health Authority
Norwegian Health Association
Introduction
Cardiovascular disease (CVD) is the leading cause of death worldwide. Several studies have shown that low cardiorespiratory fitness (CRF) is a major risk factor for CVD and is suggested to be a stronger predictor of CVD morbidity and mortality than established cardiovascular risk factors.
CRF quantified as maximal oxygen uptake (VO2max) has a strong genetic component, estimated to be ~50%. Unfortunately, current studies on genetic markers for CRF are limited by small sample sizes. In addition, there are few studies on directly measured VO2max, as most of the previous studies are based on estimated CRF. To overcome these limitations, we performed a large-scale systematic screening for genetic variants associated with VO2max aiming to provide awaited insight to this complex trait and discover possible links between VO2max and CVD.
Purpose
To identify and validate genetic factors associated with VO2max.
Methods
The genotypes of 70,000 participants from the Trøndelag Health study (HUNT) were imputed providing information on 25 million single-nucleotide polymorphisms (SNPs). We conducted a genome-wide association study (GWAS) including 4,525 participants with directly measured VO2max from the HUNT3 Fitness study. The GWAS was performed using BOLT-LMM, adjusted for age, gender, physical activity, principal components, and genotyping batch. In addition, we ran a GWAS with the same covariates except physical activity. Further, gender specific analyses were conducted. For validation, similar analyses were performed in the United Kingdom Biobank (UKBB). In the UKBB, CRF was assessed through a submaximal bicycle test. The analyses of UKBB included ~60,000 participants and over 90 million SNPs. Functional analyses of the GWAS results were examined by functional mapping and annotation (FUMA).
Results
Two GWAS-significant (p < 5×10-8) SNPs associated with VO2max were identified in the total population, two in the male population, and 24 in the female population in HUNT. Two of the 24 SNPs found in the female population were nominally significant in the UKBB. One of the validated SNPs in the female population is located inside PIK3R5, that is shown to be of importance in cardiac function and CVD. In addition, the functional analyses in the total- and male population revealed candidate SNPs in a gene previously found to be associated with endurance, PPP3CA.
Conclusions
We have identified 28 novel SNPs associated with VO2max in the HUNT cohort. Two of these SNPs were nominally validated in females in UKBB. One of the validated SNPs resides within a gene previously reported to be related to heart function and CVD. In addition, the functional analyses in the total- and male population revealed candidate SNPs in a gene previously found to be associated with endurance. Further functional analyses using bioinformatic approaches may provide more information on the physiological importance of these findings and their relation to CVD.
... Low cardiorespiratory fitness (CRF) quantified as low maximal oxygen uptake (VO2max) is one of the most important risk factors for CVD and premature death, and suggested to be a stronger predictor of morbidity and mortality than established CVD risk factors like obesity, diabetes, smoking, and hypercholesterolemia (2). VO2max is also shown to a be strong and independent predictor of allcause and diseases-specific mortality (3). Low VO2max is shown to increase risk of dementia, cancer, and other lifestyle-related diseases (4,5). ...
Funding Acknowledgements
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Central Norway Regional Health AuthorityNorwegian Health Association
Introduction
Cardiovascular disease (CVD) is the leading cause of death worldwide. Several studies have shown that low cardiorespiratory fitness (CRF) is a major risk factor for CVD. Low CRF is suggested to be a stronger predictor of CVD morbidity and mortality than established cardiovascular risk factors like obesity, diabetes, and cholesterol.
Several studies suggest that CRF quantified as maximal oxygen uptake (VO2max) has a strong genetic component, estimated to be ~50%. Unfortunately, current studies on genetic markers for CRF are limited by small sample sizes. In addition, there are few studies on directly measured VO2max, as most of the previous studies are based on estimated CRF. Directly measured VO2max is considered as the gold standard for measuring CRF. Thus, a large-scale systematic screening for genetic variants associated with VO2max may provide awaited insight to this complex trait and discover possible links between VO2max and CVD.
Purpose
To identify and validate genetic factors associated with VO2max.
Methods
The genotypes of 70.000 participants from the Trøndelag Health study (HUNT) were imputed providing information on 25 million SNPs. We conducted a genome-wide association study (GWAS) including 4525 participants with directly measured VO2max from the HUNT3 Fitness study. The GWAS was performed using BOLT-LMM, adjusted for age, gender, physical activity, principal components, and genotyping batch. In addition, we ran a GWAS with the same covariates except physical activity. Further, gender specific analyses were conducted. For validation, similar analyses were performed in the United Kingdom Biobank (UKBB). In the UKBB, CRF was assessed through a submaximal bicycle test. The analyses of UKBB included ~60.000 participants and over 90 million SNPs.
Results
Two GWAS-significant (p < 5x10-8) SNPs associated with VO2max were identified in the total population in HUNT. Further, 24 GWAS-significant SNPs associated with VO2max in females, and two GWAS-significant SNPs associated with VO2max in males were discovered. Two of the 24 SNPs found in the female population were nominally significant in the UKBB. The validated SNPs are rs376927175, an intergenic SNP downstream of APBA1, and rs551942830 (proxy for rs190675254 with LD = 1.0), a 3 Prime UTR variant inside PIK3R5. PIK3R5 encodes the regulatory subunit of one class of PI3Ks, that is shown to be of importance in cardiac function and CVD. None of the SNPs found in the total population nor the male population were validated in UKBB.
Conclusions
We have identified 28 novel SNPs associated with VO2max in the HUNT cohort. Two of these SNPs were nominally validated in females in UKBB. One of the validated SNPs resides within a gene previously reported to be related to heart function and CVD. Further functional analyses using bioinformatic approaches may provide more information on the physiological importance of these findings and their relation to CVD.
... Low cardiorespiratory fitness (CRF) quantified as low maximal oxygen uptake (VO 2max ) is one of the most important risk factors for CVD and premature death, and is suggested to be a stronger predictor of morbidity and mortality than established CVD risk factors like obesity, diabetes, smoking, and hypercholesterolemia (2). TheVO 2max is also shown to a be strong and independent predictor of allcause and diseases-specific mortality (3). LowVO 2max is shown to increase risk of dementia, cancer, and other lifestyle-related diseases (4,5). ...
Purpose:
Low cardiorespiratory fitness (CRF) is a major risk factor for CVD and a stronger predictor of CVD morbidity and mortality than established risk factors. The genetic component of CRF, quantified as peak oxygen uptake (VO2peak), is estimated to be ~60%. Unfortunately, current studies on genetic markers for CRF have been limited by small sample sizes and using estimated CRF. To overcome these limitations, we performed a large-scale systematic screening for genetic variants associated with VO2peak.
Methods:
A genome-wide association study (GWAS) was performed with BOLT-LMM including directly measured VO2peak from 4,525 participants in the HUNT3 Fitness study and 14 million single-nucleotide polymorphisms (SNPs). For validation, similar analyses were performed in the United Kingdom Biobank (UKB), where CRF was assessed through a submaximal bicycle test, including ~60,000 participants and ~ 60 million SNPs. Functional mapping and annotation of the GWAS results was conducted using FUMA.
Results:
In HUNT, two genome-wide significant SNPs associated with VO2peak were identified in the total population, two in males, and 35 in females. Two SNPs in the female population showed nominally significant association in the UKB. One of the replicated SNPs is located in PIK3R5, shown to be of importance for cardiac function and CVD. Bioinformatic analyses of the total and male population revealed candidate SNPs in PPP3CA, previously associated with CRF.
Conclusions:
We identified 38 novel SNPs associated with VO2peak in HUNT. Two SNPs were nominally replicated in UKB. Several interesting genes emerged from the functional analyses, among them one previously reported to be associated with CVD and another with CRF.
... The Cooper test was performed by running on a treadmill (Precor 966i, USA) for 12 min, and VO2max was calculated from the distance covered by running in this period of time (Tanaka et al 2000). According to the calculated VO2max expressed as ml/kg/min, the subjects were assigned to one of 5 categories of physical fitness (Strasser 2018): ...
Purpose
The effects of aerobic exercise on bone metabolism are still unclear. Thus, the main goal of this study was to explore if there was an effect of the short-term aerobic exercise program on the bone remodeling process and if there were sex differences in the effect of the training program on bone metabolism.
Methods
Twenty-one participants (men and women) aged 20–23 performed an 8-week aerobic exercise program three times per week in 1-h sessions with increases in the exercise load every 2 weeks. Bone density, bone mineral content and concentration of markers of bone metabolism: osteocalcin, C-terminal procollagen type I peptide, pyridinoline, parathyroid hormone, osteoprotegerin, and the receptor activator of nuclear kappa B ligand by ELISA were measured at the start and at the end of the study, while changes in body composition were assessed by a bioelectric impedance analysis method 6 times during the study.
Results
The aerobic exercise program increased the concentration of osteocalcin (11.34 vs 14.24 ng/ml), pyridinoline (67.51 vs 73.99 nmol/l), and the receptor activator of nuclear kappa B ligand (95.122 vs 158.15 pg/ml). A statistically significant increase in bone density at neck mean (1.122 vs 1.176 g/cm³) and in bone mineral content at dual femur (33.485 vs 33.700 g) was found in women, while there was no statistically significant change at any site in men.
Conclusion
8 weeks of the aerobic exercise program with increment in intensity increased some of bone remodeling biomarkers and showed different effects for men and women.
... It is important to recognise the integrative pathophysiological processes following COVID-19 infection and subsequent long-COVID. Cardiorespiratory fitness is a key predictor of functional capacity, quality of life, and a strong predictor of mortality [73,74]. Aerobic capacity, quantified by maximal oxygen consumption (VO 2peak ), and ventilatory efficiency, is quantified by the minute ventilation/carbon dioxide production (VE/VCO 2 ) slope, are two established measures obtained through cardio-pulmonary exercise testing and several initial studies to date have reported the impact of COVID-19 on both [75]. ...
Severe acute respiratory syndrome coronavirus type-2 (SARS-CoV-2) transmission continues to impact people globally. Whilst the acute symptoms and management strategies are well documented, millions of people globally are experiencing a prolonged and debilitating symptom profile that is reported to last months and even years. COVID-19 is a multi-system disease however the magnitude of the effects and its associated legacy is presently not well understood. Early reports indicate that multidisciplinary approaches between clinical and non-clinical entities are needed to provide effective and rehabilitative patient support pathways and restore pre-COVID-19 quality of life and functional status. Accordingly, this review provides a summary of the impact on cardiovascular, inflammatory, respiratory, and musculoskeletal function following an acute COVID-19 infection along with the prolonged effects of long-COVID.
... Aerobic training improves body composition, the functioning of the cardiovascular system, the cardiovascular lipid profile and insulin sensitivity 3 . Importantly, aerobic training increases aerobic fitness (VO2max) 3 , which is an independent predictor of health and protects against a range of chronic conditions including type 2 diabetes and cardiovascular disease 4 . Resistance training increases total muscle mass, muscle strength and power, neuromuscular firing rate 5 and recruitment and functioning of the fast twitch type 2 fibers which deteriorate with age 6 . ...
Middle-aged (50-64yrs) and older adults (65-90yrs) in Laois predominantly undertook sufficient aerobic activities to improve health, but most did not meet the guidelines for resistance, balance or flexibility training. Thus, educating middle-aged and older adults on the benefits of multimodal PA and providing enjoyable opportunities for both populations within the community that focus on social inclusion is required.
Background
Kaempferol (KMP), a flavonoid in edible plants, exhibits diverse pharmacological effects. Growing body of evidence associates extended lifespan with physical activity (PA) and sleep, but KMP’s impact on these behaviors is unclear. This double-blind, placebo-controlled, crossover trial assessed KMP’s effects on PA and sleep.
Methods
A total of 33 city workers (17 males and 16 females) participated in this study. They were randomly assigned to take either 10 mg of KMP or placebo for 2 weeks in the order allocated, with a 7-day washout period in between. All participants wore an accelerometer-based wearable device (Fitbit Charge 4), which monitored daily PA, heart rate (HR), and HR variability during sleep.
Results
The duration of wearing the device was 23.73 ± 0.04 h/day. HR decreased in each PA level, and the mean daily step count and distance covered increased significantly during KMP intake compared to placebo. The outing rate, number of trips, number of recreational activities, and time spent in recreation on weekends increased. Sleep quality improved following KMP intake. The decrease in HR and increase in RMSSD may be important in mediating the effects of these KMPs.
Conclusion
KMP leads to behavioral changes that subsequently improve sleep quality and potentially improve long-term quality of life.
Clinical Trial Registration
https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000048447, UMIN000042438.
Objective:To evaluate cardiovascular health (CVH) in university workers at a higher education institution in relation to other health-related factors.Methods:Cross-sectional study consisting of 121 workers. CVH was assessed by seven measures [food consumption, physical activity level (PAL), smoking, total cholesterol, blood glucose, systemic blood pressure (BP), and body mass index (BMI)]. The independent variables waist circumference (WC), waist-hip ratio (WHR), HDL-c, LDL-c, triglycerides, maximal oxygen consumption (VO2max), workload, and health related quality of life (HRQoL)were assessed. Results:Overall, 25% of the sample had poor CVH. The ideal CVH group had lower WC (p<0.001) and WHR (p<0.001), and higher VO2max(p=0.041). The physical component score was higher in the groups with intermediate (p=0.036) and ideal (p=0.002) CVH. Daily workload was higher in the poor CVH group (p=0.05). CVH score was directly related to VO2max(p=0.001) and physical component (p=0.020), and inversely related to WC (p<0.001), WHR (p<0.001), LDL-c (p<0.001), and triglycerides (p< 0.001). Conclusion:Implementation of educational practices, and promotion of physical activity, adequate dietary intake, and other lifestyle habits can help to improve CVH and the physical component of HRQoL.
Introdução: A Força Aérea Brasileira é uma instituição militar integrante das forças armadas responsável pela segurança e controle do espaço aéreo nacional. Para o exercício das funções militares os oficiais necessitam de uma boa aptidão física que é a expressão do estado de sanidade física e mental que o habilita ao exercício das atividades funcionais dos cargos militares do posto, quadro e categoria a que pertence. Objetivo: comparar a aptidão física dos voluntários antes e após o primeiro mês de Estágio de Adaptação da Base Aérea de Fortaleza no Estado do Ceará. Metodologia: Trata-se de um estudo quantitativo, observacional analítico. A amostra foi constituída por 12 voluntários de ambos os sexos com idade média de 36 anos. Os estagiários foram submetidos a um estágio de adaptação com duração de dois meses foram comparadas as médias dos testes físicos antes e após trinta dias. Resultados: Foi identificado diferenças estatísticas significantes (P<0,05) entre as médias dos testes de flexão de braço, abdominal, corrida de 12 minutos. Foi observado um aumento estatisticamente significante na capacidade aeróbia estimada pelo Vo2máx. Conclusão: A rotina imposta aos Estagiários nos primeiros 30 dias no Estágio de Adaptação na Base Aérea de Fortaleza desencadeou alterações fisiológicas suficientes para promove um melhor desempenho nos testes físicos.
Background
Neurofilament Light Chain (NfL) is a biomarker of axonal injury elevated in mild cognitive impairment (MCI) and Alzheimer’s disease dementia. Blood NfL also inversely correlates with cognitive performance in those conditions. However, few studies have assessed NfL as a biomarker of global cognition in individuals demonstrating mild cognitive deficits who are at risk for vascular-related cognitive decline.
Objective
To assess the relationship between blood NfL and global cognition in individuals with possible vascular MCI (vMCI) throughout cardiac rehabilitation (CR). Additionally, NfL levels were compared to age/sex-matched cognitively unimpaired (CU) controls.
Method
Participants with coronary artery disease (vMCI or CU) were recruited at entry to a 24-week CR program. Global cognition was measured using the Montreal Cognitive Assessment (MoCA) and plasma NfL level (pg/ml) was quantified using a highly sensitive enzyme-linked immunosorbent assay.
Results
Higher plasma NfL was correlated with worse MoCA scores at baseline (β = −.352, P = .029) in 43 individuals with vMCI after adjusting for age, sex, and education. An increase in NfL was associated with worse global cognition (b[SE] = −4.81[2.06], P = .023) over time, however baseline NfL did not predict a decline in global cognition. NfL levels did not differ between the vMCI (n = 39) and CU (n = 39) groups (F(1, 76) = 1.37, P = .245).
Conclusion
Plasma NfL correlates with global cognition at baseline in individuals with vMCI, and is associated with decline in global cognition during CR. Our findings increase understanding of NfL and neurobiological mechanisms associated with cognitive decline in vMCI.
Currently, a major pulmonary rehabilitation focus is on expanding access. At-home rehabilitation is being explored as an in-center pulmonary rehabilitation alternative. It has been asserted that in-home pulmonary rehabilitation confers similar benefits to in-center pulmonary rehabilitation. An extensive database documents that in-center pulmonary rehabilitation confers a range of patient-relevant benefits. Recently, evidence has been presented that in-center pulmonary rehabilitation improves survival, perhaps the most important benefit of all. It can be argued that improvements in physical fitness, assessed as exercise capacity, are mechanistically related to survival improvements. Therefore, in-home rehabilitation must demonstrate exercise capacity improvements similar to those regularly seen in-center to be considered equivalent. A literature search identified 11 studies that compared in-home with in-center pulmonary rehabilitation for COPD that recorded exercise tolerance outcomes. Despite being described as in-home programs, almost all featured prefatory in-center evaluation; some featured in-home visits by rehabilitation professionals. In 6 of the 11 studies, only walking exercise was prescribed. Only 3 included 2-way audio/visual patient-therapist contact. With regard to exercise outcomes; in 3, there was greater in-center group improvement; in 4, outcomes were similar; and, in 4, the in-center group failed to demonstrate clinically important exercise outcome increases; decidedly mixed results. Importantly, in 8 of 11 studies, the 6-min walk test was an exercise outcome. It is argued that the 6-min walk test does not generally elicit physiologically maximum responses and cannot be used to assess exercise capacity improvements. Of the 4 studies that used other exercise outcomes, in 2, exercise endurance increase was similar between in-home and in-center groups; in the other 2, the in-center group had superior improvements. Mixed results indeed! In conclusion, there is insufficient evidence to conclude that in-home pulmonary rehabilitation yields improvements equivalent to center-based programs in physical function, the outcome likely driving long-term prognosis. Moreover, it needs to be established which of the wide variety of in-home program designs now being offered should be promoted.
Objective
There is widespread agreement about the key role of hemoglobin for oxygen transport. Both observational and interventional studies have examined the relationship between hemoglobin levels and maximal oxygen uptake (V˙O2max) in humans. However, there exists considerable variability in the scientific literature regarding the potential relationship between hemoglobin and V˙O2max. Thus, we aimed to provide a comprehensive analysis of the diverse literature and examine the relationship between hemoglobin levels (hemoglobin concentration and mass) and V˙O2max (absolute and relative V˙O2max) among both observational and interventional studies.
Methods
A systematic search was performed on December 6th, 2021. The study procedures and reporting of findings followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Article selection and data abstraction were performed in duplicate by two independent reviewers. Primary outcomes were hemoglobin levels and V˙O2max values (absolute and relative). For observational studies, meta-regression models were performed to examine the relationship between hemoglobin levels and V˙O2max values. For interventional studies, meta-analysis models were performed to determine the change in V˙O2max values (standard paired difference) associated with interventions designed to modify hemoglobin levels or V˙O2max. Meta-regression models were then performed to determine the relationship between a change in hemoglobin levels and the change in V˙O2max values.
Results
Data from 384 studies (226 observational studies and 158 interventional studies) were examined. For observational data, there was a positive association between absolute V˙O2max and hemoglobin levels (hemoglobin concentration, hemoglobin mass, and hematocrit (P<0.001 for all)). Prespecified subgroup analyses demonstrated no apparent sex-related differences among these relationships. For interventional data, there was a positive association between the change of absolute V˙O2max (standard paired difference) and the change in hemoglobin levels (hemoglobin concentration (P<0.0001) and hemoglobin mass (P = 0.006)).
Conclusion
These findings suggest that V˙O2max values are closely associated with hemoglobin levels among both observational and interventional studies. Although our findings suggest a lack of sex differences in these relationships, there were limited studies incorporating females or stratifying results by biological sex.
Background:
Oxygen consumption is an important index to evaluate in cardiac patients, particularly those with heart failure, and is measured in the setting of advanced cardiopulmonary exercise testing. However, technological advances now allow for the estimation of this parameter in many consumer and medical-grade wearable devices, making it available for the medical provider at the initial evaluation of patients. We report a case of an apparently healthy male aged 40 years who presented for evaluation due to an Apple Watch (Apple Inc) notification of low cardiac fitness. This alert triggered a thorough workup, revealing a diagnosis of familial nonischemic cardiomyopathy with severely reduced left ventricular systolic function. While the use of wearable devices for the measurement of oxygen consumption and related parameters is promising, further studies are needed for validation.
Objective:
The aim of this report is to investigate the potential utility of wearable devices as a screening and risk stratification tool for cardiac fitness for the general population and those with increased cardiovascular risk, particularly through the measurement of peak oxygen consumption (VO2). We discuss the possible advantages of measuring oxygen consumption using wearables and propose its integration into routine patient evaluation and follow-up processes. With the current evidence and limitations, we encourage researchers and clinicians to explore bringing wearable devices into clinical practice.
Methods:
The case was identified at Sheba Medical Center, and the patient's cardiac fitness was monitored through an Apple Watch Series 6. The patient underwent a comprehensive cardiac workup following his presentation. Subsequently, we searched the literature for articles relating to the clinical utility of peak VO2 monitoring and available wearable devices.
Results:
The Apple Watch data provided by the patient demonstrated reduced peak VO2, a surrogate index for cardiac fitness, which improved after treatment initiation. A cardiological workup confirmed familial nonischemic cardiomyopathy with severely reduced left ventricular systolic function. A review of the literature revealed the potential clinical benefit of peak VO2 monitoring in both cardiac and noncardiac scenarios. Additionally, several devices on the market were identified that could allow for accurate oxygen consumption measurement; however, future studies and approval by the Food and Drug Administration (FDA) are still necessary.
Conclusions:
This case report highlights the potential utility of peak VO2 measurements by wearable devices for early identification and screening of cardiac fitness for the general population and those at increased risk of cardiovascular disease. The integration of wearable devices into routine patient evaluation may allow for earlier presentation in the diagnostic workflow. Cardiac fitness can be serially measured using the wearable device, allowing for close monitoring of functional capacity parameters. Devices need to be used with caution, and further studies are warranted.
This study aims to determine the effect of motivation, self-confidence, and maximum oxygen consumption on the basic skills of playing soccer. This research includes path analysis research (path analysis). Exogenous variables are motivation (x1), confidence (x2), and maximum oxygen consumption (x3), while endogenous variables are the basic skills of playing soccer. The sample of this research was 100 male students of class XI MAN 2 Bone. Data were analyzed by inferential statistical analysis, namely the regression test. The findings showed that motivation (MTV), self-confidence (PD), and maximum oxygen ability (VO2 max) affected the basic skills of playing soccer (KSB) (p<0.05). This study only involved a small sample, so the findings of this study can still be developed for further research using more methods or samples.
Background and aims:
We present findings from the inaugural American College of Sports Medicine (ACSM) International Multidisciplinary Roundtable, which was convened to evaluate the evidence for physical activity as a means of preventing or modifying the course of NAFLD.
Approach and results:
A scoping review was conducted to map the scientific literature and identify key concepts, research gaps, and evidence available to inform clinical practice, policymaking, and research. The scientific evidence demonstrated regular physical activity is associated with decreased risk of NAFLD development. Low physical activity is associated with a greater risk for disease progression and extrahepatic cancer. During routine health care visits, all patients with NAFLD should be screened for and counseled about physical activity benefits, including reduction in liver fat and improvement in body composition, fitness, and quality of life. While most physical activity benefits occur without clinically significant weight loss, evidence remains limited regarding the association between physical activity and liver fibrosis. At least 150 min/wk of moderate or 75 min/wk of vigorous-intensity physical activity are recommended for all patients with NAFLD. If a formal exercise training program is prescribed, aerobic exercise with the addition of resistance training is preferred.
Conclusions:
The panel found consistent and compelling evidence that regular physical activity plays an important role in preventing NAFLD and improving intermediate clinical outcomes. Health care, fitness, and public health professionals are strongly encouraged to disseminate the information in this report. Future research should prioritize determining optimal strategies for promoting physical activity among individuals at risk and in those already diagnosed with NAFLD.
Background Maximal oxygen uptake and muscle strength are fundamental components of physical fitness. Improving these capacities is highly beneficial to health. The validity of maximal oxygen uptake and muscle strength has been widely emphasized in clinical, sports, and research-related settings. However, many of the previous tests required special equipment and space. Aim This study examined the effectiveness of field tests that do not require special equipment or space. Materials and methods The relationship between the 3-minute burpee test (3MBT) and estimated maximal oxygen uptake (Yo-Yo intermittent recovery test (Yo-Yo IRT)) using whole-body muscle groups was examined. The subjects were young men (n=127) with a history of exercising at least once a week. Results A strong relationship between 3MBT and Yo-YoIRT was shown (p<0.001). Conclusions The 3MBT is a field test that can be performed anytime and anywhere there is space for plank and standing postures. Because it is very brief, efficient, and uses muscle groups throughout the body, it is effective and potentially quite useful as a new field test.
Physical activity (PA) is a key component for brain health and Reserve, and it is among the main dementia protective factors. However, the neurobiological mechanisms underpinning Reserve are not fully understood. In this regard, a noradrenergic (NA) theory of cognitive reserve (Robertson, 2013) has proposed that the upregulation of NA system might be a key factor for building reserve and resilience to neurodegeneration because of the neuroprotective role of NA across the brain. PA elicits an enhanced catecholamine response, in particular for NA. By increasing physical commitment, a greater amount of NA is synthetised in response to higher oxygen demand. More physically trained individuals show greater capabilities to carry oxygen resulting in greater
– a measure of oxygen uptake and physical fitness (PF).
Methods
We hypothesized that greater
would be related to greater Locus Coeruleus (LC) MRI signal intensity. In a sample of 41 healthy subjects, we performed Voxel-Based Morphometry analyses, then repeated for the other neuromodulators as a control procedure (Serotonin, Dopamine and Acetylcholine).
Results
As hypothesized, greater
related to greater LC signal intensity, and weaker associations emerged for the other neuromodulators.
Conclusion
This newly established link between
and LC–NA system offers further understanding of the neurobiology underpinning Reserve in relationship to PA. While this study supports Robertson's theory proposing the upregulation of the NA system as a possible key factor building Reserve, it also provides ground for increasing LC–NA system resilience to neurodegeneration via
enhancement.
Human skeletal muscle demonstrates remarkable plasticity, adapting to numerous external stimuli including the habitual level of contractile loading. Accordingly, muscle function and exercise capacity encompass a broad spectrum, from inactive individuals with low levels of endurance and strength, to elite athletes who produce prodigious performances underpinned by pleiotropic training-induced muscular adaptations. Our current understanding of the signal integration, interpretation and output coordination of the cellular and molecular mechanisms that govern muscle plasticity across this continuum is incomplete. As such, training methods and their application to elite athletes largely rely on a "trial and error" approach with the experience and practices of successful coaches and athletes often providing the bases for "post hoc" scientific enquiry and research. This review provides a synopsis of the morphological and functional changes along with the molecular mechanisms underlying exercise adaptation to endurance- and resistance-based training. These traits are placed in the context of innate genetic and inter-individual differences in exercise capacity and performance, with special considerations given to the ageing athletes. Collectively, we provide a comprehensive overview of skeletal muscle plasticity in response to different modes of exercise, and how such adaptations translate from "molecules to medals".
Cette thèse avait pour ambition de contribuer à la compréhension des effets des variables de contrôle sur la performance, que sont le temps, la vitesse, la perception de l'effort (article 1), la distance (article 2) ainsi que V̇O2 et la fréquence cardiaque (article 3). Nous avons pu réaliser ce travail en utilisant les nouvelles possibilités qu'offrent les nouvelles technologies affranchissant le physiologiste du tapis roulant tout en disposant de la possibilité de contrôler par Bluetooth® toutes les variables physiologiques. Nous avons mis en évidence que : 1) les athlètes étaient capables d'adapter et de reproduire des réponses physiologiques non seulement en intensité mais en durée (article 1), 2) lorsque la variable de contrôle est la distance avec une mise en situation de compétition, la contribution de l'énergie à V̇O2max était relativement identique en proportion de l'énergie aérobie et ce, du 100 au 10,000m (article 2). Il y aurait donc un continuum énergétique allant du sprint au 10 kilomètres qui pourrait être une information intégrée dans l'organisme de façon centrale (demi-fond et fond) ou métabolique (sprint), 3) Enfin, nous avons montré que même dans un effort assez long (12 minutes) et maximal, le coureur tirait bénéfice d'une aide de contrôle « physiologique » par la fréquence cardiaque ou V̇O2 pour parvenir à sa meilleure performance. En conclusion, ce travail de thèse propose une méthodologie dans laquelle le coureur devient autonome dans le choix de sa stratégie de vitesse en s'affranchissant des calculs de vitesse cible à partir des seuils physiologiques, V̇O2max et autres facteurs physiologiques rendus limitants en cela.
The aim of this systematic review and meta-analysis was to evaluate the association between glycemic control (HbA1c) and functional capacity (VO2max) in individuals with type 1 diabetes (T1DM). A systematic literature search was conducted in EMBASE, PubMed, Cochrane Central Register of Controlled Trials, and ISI Web of Knowledge for publications from January 1950 until July 2020. Randomized and observational controlled trials with a minimum number of three participants were included if cardio-pulmonary exercise tests to determine VO2maxand HbA1c measurement has been performed. Pooled mean values were estimated for VO2maxand HbA1c and weighted Pearson correlation and meta-regression were performed to assess the association between these parameters. We included 187 studies with a total of 3278 individuals with T1DM. The pooled mean HbA1c value was 8.1% (95%CI; 7.9–8.3%), and relative VO2maxwas 38.5 mL/min/kg (37.3–39.6). The pooled mean VO2maxwas significantly lower (36.9 vs. 40.7, p = 0.001) in studies reporting a mean HbA1c >7.5% compared to studies with a mean HbA1c ≤7.5%. Weighted Pearson correlation coefficient was r = −0.19 (p < 0.001) between VO2maxand HbA1c. Meta-regression adjusted for age and sex showed a significant decrease of −0.94 mL/min/kg in VO2maxper HbA1c increase of 1% (p = 0.024). In conclusion, we were able to determine a statistically significant correlation between HbA1c and VO2maxin individuals with T1DM. However, as the correlation was only weak, the association of HbA1c and VO2maxmight not be of clinical relevance in individuals with T1DM.
Physical inactivity is the fourth leading global cause of death and is a major contributor to metabolic and endocrine diseases. In this review we provide a current update of the past 5 years in the field as it pertains to the most prevalent and deadly chronic diseases. Despite the prevalence of physical inactivity in modern society, it remains largely overlooked relative to other comparable risk factors such as obesity, and our molecular understanding of how physical inactivity impacts metabolism is still partially unknown. Therefore, we discuss current clinical inactivity models along with their most recent findings regarding health outcomes along with any discrepancies that are present in the field. Lastly, we discuss future directions and the need for translatable animal models of physical inactivity to discover novel molecular targets for the prevention of chronic disease.
Elite masters endurance athletes are considered models of optimal healthy aging due to the maintenance of high cardiorespiratory fitness (CRF) until old age. Whereas a drop in VO2max in masters athletes has been broadly investigated, the modifying impact of training still remains a matter of debate. Longitudinal observations in masters endurance athletes demonstrated VO2max declines between −5% and −46% per decade that were closely related to changes in training volume. Here, using regression analyses, we show that 54% and 39% of the variance in observed VO2max decline in male and female athletes, respectively is explained by changes in training volume. An almost linear VO2max decrease was observed in studies on young and older athletes, as well as non-athletes, starting a few days after training cessation, with a decline of as much as −20% after 12 weeks. Besides a decline in stroke volume and cardiac output, training cessation was accompanied by considerable reductions in citrate synthase and succinate dehydrogenase activity (reduction in mitochondrial content and oxidative capacity). This reduction could largely be rescued within similar time periods of training (re)uptake. It is evident that training reduction or cessation leads to a considerably accelerated VO2max drop, as compared to the gradual aging-related VO2max decline, which can rapidly nullify many of the benefits of preceding long-term training efforts.
Introduction: The genetic disorder causing Down syndrome (DS) affects the cardiorespiratory and hemodynamic parameters. When exercising, sufficient blood flow is necessary for active muscles. Cardiac output (Q) must be proportional to the peripheral requirements. In case the stroke volume (SV) is lower, the heart rate (HR) will increase further in order to maintain an adequate blood flow in the active territories (HR compensatory response). People with DS have a lower HR response to maximal exercise. Nevertheless, the response of the hemodynamic and cardiorespiratory parameters during the submaximal phases of maximal exercise was not well studied.
Objective: to evaluate cardiorespiratory and hemodynamic parameters 1) during submaximal and 2) maximal metabolic treadmill test in individuals with and without DS.
Methods: fifteen adults with DS (age = 27.33 ± 4.98 years old; n = 12 males/3 females) and 15 adults without disabilities, matched by age and sex, participated in this cross-sectional study. Peak and submaximal cardiorespiratory and hemodynamic parameters were measured during a treadmill test. Linear mixed-effects models were used to analyse interactions between the variables. Post-hoc analyses were employed to assess within and between-group differences.
Results: The DS group showed lower peak values for ventilation (VE), respiratory exchange ratio (RER), tidal volume (VT), ventilatory equivalent for O2 (VEqO2), end-tidal partial pressure for O2 (PETO2), O2 uptake (VO2) and CO2 production (all p < 0 .050), Q, SV, systolic and diastolic blood pressure (SBP, DBP), and HR (all p < 0 .050). There were group-by-time interactions (all p < 0 .050) for all ventilatory submaximal values. Significant group and time differences were observed for VE; RER; respiratory rate (RR); VEqO2; PETO2; VO2, and VT (all p < 0 .050). There were also group-by-time interactions (all p < 0 .050) and group and time differences for SBP, mean arterial blood pressure (MAP) and HR (all p < 0.010).
Conclusion: During submaximal exercise, we verified a compensatory response of HR, and greater VE and VO2 in the individuals with DS. In addition, we were able to observe that the DS group had a reduced SBP and MAP response to submaximal exercise. On the other hand, we found that adults with DS have lower peak hemodynamic and cardiorespiratory values, and a lower cardiac reserve. Further research is warranted to investigate the effects of these results on the general health of adults with DS and the impact of long-term exercise programs on these parameters.
Introdução: A prática de corrida é uma importante estratégia para o indivíduo tornar-se fisicamente ativo, entretanto muitos praticam de forma recreacional e sem supervisão profissional, neste sentido a literatura carece de estudos sobre os efeitos sobre esta prática de exercícios para a saúde cardiovascular. Objetivo: Avaliar a influência da corrida recreativa na capacidade cardiorrespiratória em mulheres adultas. Materiais e Métodos: Neste estudo descritivo, comparativo e quase-experimental, a amostra foi composta por 60 mulheres adultas distribuídas em dois grupos: Grupo Não Praticantes (n=29), com idade de (33,17 ± 11,58 anos) e Grupo Praticantes (n=31), com idade de (40,1 ± 10,5 anos). Após avaliação da massa corporal e estatura, foi calculado o índice de massa corporal das participantes. Em seguida, ambos os grupos foram submetidos ao teste de esteira para avaliar a capacidade cardiorrespiratória. A frequência cardíaca e a percepção subjetiva de esforço (0 a 10) foram monitoradas durante todo o teste. Resultados: Em relação ao índice de massa corporal não foram encontradas diferenças significativas entre os grupos. Quanto ao teste de capacidade cardiorrespiratória os resultados foram estatisticamente maiores no grupo praticantes em relação ao grupo não praticantes. Conclusão: A corrida recreativa melhora capacidade cardiorrespiratória contribuindo para prevenção de doenças e proteção a saúde de mulheres de meia idade.
Background
A negative impact of premature birth on health in adulthood is well established. However, it is not clear whether healthy adults who were born prematurely but have similar physical activity levels compared to adults born at term have a reduced maximal aerobic exercise capacity (maximum oxygen consumption [VO2max]).
Objective
We aimed to determine the effect of premature birth on aerobic exercise capacity and lung function in otherwise healthy, physically active individuals.
Methods
A broad literature search was conducted in the PubMed database. Search terms included ‘preterm/premature birth’ and ‘aerobic exercise capacity’. Maximal oxygen consumption (mL/kg/min) was the main variable required for inclusion, and amongst those investigations forced expiratory volume in 1 s (FEV1, % predicted) was evaluated as a secondary parameter. For the systematic review, 29 eligible articles were identified. Importantly, for the meta-analysis, only studies which reported similar activity levels between healthy controls and the preterm group/s were included, resulting in 11 articles for the VO2max analysis (total n = 688, n = 333 preterm and n = 355 controls) and six articles for the FEV1 analysis (total n = 296, n = 147 preterm and n = 149 controls). Data were analysed using Review Manager ( Review Manager. RevMan version 5.4 software. The Cochrane Collaboration; 2020.).
Results
The systematic review highlighted the broad biological impact of premature birth. While the current literature tends to suggest that there may be a negative impact of premature birth on both VO2max and FEV1, several studies did not control for the potential influence of differing physical activity levels between study groups, thus justifying a focused meta-analysis of selected studies. Our meta-analysis strongly suggests that prematurely born humans who are otherwise healthy do have a reduced VO2max (mean difference: − 4.40 [95% confidence interval − 6.02, − 2.78] mL/kg/min, p < 0.00001, test for overall effect: Z = 5.32) and FEV1 (mean difference − 9.22 [95% confidence interval − 13.54, − 4.89] % predicted, p < 0.0001, test for overall effect: Z = 4.18) independent of physical activity levels.
Conclusions
Whilst the current literature contains mixed findings on the effects of premature birth on VO2max and FEV1, our focused meta-analysis suggests that even when physical activity levels are similar, there is a clear reduction in VO2max and FEV1 in adults born prematurely. Therefore, future studies should carefully investigate the underlying determinants of the reduced VO2max and FEV1 in humans born preterm, and develop strategies to improve their maximal aerobic capacity and lung function beyond physical activity interventions.
A poor Fitness Fatness Index (FFI) is associated with type 2 diabetes incidence, other chronic conditions (Alzheimer’s, cancer, and cardiovascular disease) and all-cause mortality. Recent investigations have proposed that an individualised exercise prescription based on ventilatory thresholds is more effective than a standardised prescription in improving cardiorespiratory fitness (CRF), a key mediator of FFI. Thus, the aim of the current study was to determine the effectiveness of individualised versus standardised exercise prescription on FFI in sedentary adults. Thirty-eight sedentary individuals were randomised to 12-weeks of: (1) individualised exercise training using ventilatory thresholds (n = 19) or (2) standardised exercise training using a percentage of heart rate reserve (n = 19). A convenience sample was also recruited as a control group (n=8). Participants completed CRF exercise training three days per week, for 12-weeks on a motorised treadmill. FFI was calculated as CRF in metabolic equivalents (METs), divided by fatness determined by waist to height ratio (WtHR). A graded exercise test was used to measure CRF, and anthropometric measures (height and waist circumference) were assessed to ascertain WtHR. There was a difference in FFI change between study groups, whilst controlling for baseline FFI, F (2, 42) = 19.382 p < .001, partial η2 = 0.480. The magnitude of FFI increase from baseline was significantly higher in the individualised (+15%) compared to the standardised (+10%) (p = 0.028) and control group (+4%) (p = <.001). The main finding of the present study is that individualised exercise prescription had the greatest effect on improving FFI in sedentary adults compared to a standardised prescription. Therefore, an individualised based exercise prescription should be considered a viable and practical method of improving FFI in sedentary adults.
Background
International evidence-based guidelines recommend physical exercise to form part of standard care for all cancer survivors. However, at present, the optimum exercise intensity is unclear. Therefore, we aimed to evaluate the effectiveness of a high intensity (HI) and low-to-moderate intensity (LMI) resistance and endurance exercise program compared with a wait list control (WLC) group on physical fitness and fatigue in a mixed group of cancer survivors who completed primary cancer treatment, including chemotherapy.
Methods
Overall, 277 cancer survivors were randomized to 12 weeks of HI exercise (n = 91), LMI exercise (n = 95), or WLC (n = 91). Both interventions were identical with respect to exercise type, duration and frequency, and only differed in intensity. Measurements were performed at baseline (4–6 weeks after primary treatment) and post-intervention. The primary outcomes were cardiorespiratory fitness (peakVO2), muscle strength (grip strength and 30-second chair-stand test), and self-reported fatigue (Multidimensional Fatigue Inventory; MFI). Secondary outcomes included health-related quality of life, physical activity, daily functioning, body composition, mood, and sleep disturbances. Multilevel linear regression analyses were performed to estimate intervention effects using an intention-to-treat principle.
Results
In the HI and LMI groups, 74 % and 70 % of the participants attended more than 80 % of the prescribed exercise sessions, respectively (P = 0.53). HI (β = 2.2; 95 % CI, 1.2–3.1) and LMI (β = 1.3; 95 % CI, 0.3–2.3) exercise showed significantly larger improvements in peakVO2 compared to WLC. Improvements in peakVO2 were larger for HI than LMI exercise (β = 0.9; 95 % CI, −0.1 to 1.9), but the difference was not statistically significant (P = 0.08). No intervention effects were found for grip strength and the 30-second chair-stand test. HI and LMI exercise significantly reduced general and physical fatigue and reduced activity (MFI subscales) compared to WLC, with no significant differences between both interventions. Finally, compared to WLC, we found benefits in global quality of life and anxiety after HI exercise, improved physical functioning after HI and LMI exercise, and less problems at work after LMI exercise.
Conclusions
Shortly after completion of cancer treatment, both HI and LMI exercise were safe and effective. There may be a dose–response relationship between exercise intensity and peakVO2, favoring HI exercise. HI and LMI exercise were equally effective in reducing general and physical fatigue.
Trial registration
This study was registered at the Netherlands Trial Register [NTR2153] on the 5th of January 2010.
Muscle atrophy is an unfortunate effect of aging and many diseases and can compromise physical function and impair vital metabolic processes. Low levels of muscular fitness together with insufficient dietary intake are major risk factors for illness and mortality from all causes. Ultimately, muscle wasting contributes significantly to weakness, disability, increased hospitalization, immobility, and loss of independence. However, the extent of muscle wasting differs greatly between individuals due to differences in the aging process per se as well as physical activity levels. Interventions for sarcopenia include exercise and nutrition because both have a positive impact on protein anabolism but also enhance other aspects that contribute to well-being in sarcopenic older adults, such as physical function, quality of life, and anti-inflammatory state. The process of aging is accompanied by chronic immune activation, and sarcopenia may represent a consequence of a counter-regulatory strategy of the immune system. Thereby, the kynurenine pathway is induced, and elevation in the ratio of kynurenine to tryptophan concentrations, which estimates the tryptophan breakdown rate, is often linked with inflammatory conditions and neuropsychiatric symptoms. A combined exercise program consisting of both resistance-type and endurance-type exercise may best help to ameliorate the loss of skeletal muscle mass and function, to prevent muscle aging comorbidities, and to improve physical performance and quality of life. In addition, the use of dietary protein supplementation can further augment protein anabolism but can also contribute to a more active lifestyle, thereby supporting well-being and active aging in the older population.
Background:
Evidence regarding the efficacy of nutritional supplementation to enhance exercise training responses in COPD patients with low muscle mass is limited. The objective was to study if nutritional supplementation targeting muscle derangements enhances outcome of exercise training in COPD patients with low muscle mass.
Methods:
Eighty-one COPD patients with low muscle mass, admitted to out-patient pulmonary rehabilitation, randomly received oral nutritional supplementation, enriched with leucine, vitamin D, and omega-3 fatty acids (NUTRITION) or PLACEBO as adjunct to 4 months supervised high intensity exercise training.
Results:
The study population (51% males, aged 43-80) showed moderate airflow limitation, low diffusion capacity, normal protein intake, low plasma vitamin D, and docosahexaenoic acid. Intention-to-treat analysis revealed significant differences after 4 months favouring NUTRITION for body mass (mean difference ± SEM) (+1.5 ± 0.6 kg, P = 0.01), plasma vitamin D (+24%, P = 0.004), eicosapentaenoic acid (+91%,P < 0.001), docosahexaenoic acid (+31%, P < 0.001), and steps/day (+24%, P = 0.048). After 4 months, both groups improved skeletal muscle mass (+0.4 ± 0.1 kg, P < 0.001), quadriceps muscle strength (+12.3 ± 2.3 Nm,P < 0.001), and cycle endurance time (+191.4 ± 34.3 s, P < 0.001). Inspiratory muscle strength only improved in NUTRITION (+0.5 ± 0.1 kPa, P = 0.001) and steps/day declined in PLACEBO (-18%,P = 0.005).
Conclusions:
High intensity exercise training is effective in improving lower limb muscle strength and exercise performance in COPD patients with low muscle mass and moderate airflow obstruction. Specific nutritional supplementation had additional effects on nutritional status, inspiratory muscle strength, and physical activity compared with placebo.
Background:
Age-related differences concerning cardiorespiratory responses and myocardial function during exercise have not been extensively investigated in healthy populations.
Aims:
To compare cardiorespiratory performance and myocardial function during maximal exercise in healthy/unmedicated men (older, n = 24, 63-75 years; young, n = 22, 19-25 years) and women (older, n = 18, age = 63-74 years; young, n = 23, 19-25 years).
Methods:
Oxygen uptake (VO2), ventilation minute (V E), heart rate (HR), stroke volume (SV), cardiac output (Q), O2 pulse (O2p), preejection period (PEP), and left ventricular ejection time (LVET) were assessed during cycle incremental exercise.
Results:
HR and SV remained equivalent between age groups until 75 and 50% peak workload, respectively. Q increased by 2.5 and 4.5 times in older and young groups, respectively. However, Q/VO2 ratio was always similar across age and sex groups (∼0.50). The energetic efficiency ratio (W/VO2) was also alike in older and young men, but slightly lower in women. At maximal exercise, cardiorespiratory responses were lower in older than young men and women: VO2 (-40 to 50%), V E (-35 to 37%), HR (-23%), SV (-26 to 29%), Q (-43 to 45%), and O2p (-15 to 20%). Cardiac and SV indices were lower in older than young groups by approximately 42 and 25%, respectively. LVET was longer in the older individuals, while PEP was similar across age groups. Hence, PEP/LVET was lowered among older vs. young men and women.
Conclusion:
Submaximal work capacity was preserved in healthy and unmedicated older individuals. Age-related lessening of maximal performance in both sexes was due to poor chronotropic and, particularly, inotropic properties of the heart.
The prevalence of type 2 diabetes (T2D) is rapidly increasing, and effective strategies to manage and prevent this disease are urgently needed. Resistance training (RT) promotes health benefits through increased skeletal muscle mass and qualitative adaptations, such as enhanced glucose transport and mitochondrial oxidative capacity. In particular, mitochondrial adaptations triggered by RT provide evidence for this type of exercise as a feasible lifestyle recommendation to combat T2D, a disease typically characterized by altered muscle mitochondrial function. Recently, the synergistic and antagonistic effects of combined training and Metformin use have come into question and warrant more in-depth prospective investigations. In the future, clinical intervention studies should elucidate the mechanisms driving RT-mitigated mitochondrial adaptations in muscle and their link to improvements in glycemic control, cholesterol metabolism and other cardiovascular disease risk factors in individuals with T2D.
Background
Reduced muscular strength in the old age is strongly related to activity impairment and mortality. However, studies evaluating the gender-specific association between muscularity and mortality among older adults are lacking. Thus, the objective of the present study was to examine gender differences in the association between muscular strength and mortality in a prospective population-based cohort study. Methods
Data used in this study derived from the Cooperative Health Research in the Region of Augsburg (KORA)-Age Study. The present analysis includes 1,066 individuals (mean age 76 ± 11 SD years) followed up over 3 years. Handgrip strength was measured using the Jamar Dynamometer. A Cox proportional hazard model was used to determine adjusted hazard ratios of mortality with 95% confidence intervals (95% CI) for handgrip strength. Potential confounders (i.e. age, nutritional status, number of prescribed drugs, diseases and level of physical activity) were pre-selected according to evidence-based information. ResultsDuring the follow-up period, 56 men (11%) and 39 women (7%) died. Age-adjusted mortality rates per 1,000 person years (95% CI) were 77 (59–106), 24 (13–41) and 14 (7–30) for men and 57 (39–81), 14 (7–27) and 1 (0–19) for women for the first, second and third sex-specific tertile of muscular strength, respectively. Low handgrip strength was significantly associated with all-cause mortality among older men and women from the general population after controlling for significant confounders. Hazard ratios (95% CI) comparing the first and second tertile to the third tertle were 3.33 (1.53–7.22) and 1.42 (0.61-3.28), respectively. Respective hazard ratios (95% CI) for mortality were higher in women than in men ((5.23 (0.67–40.91) and 2.17 (0.27–17.68) versus 2.36 (0.97–5.75) and 0.97 (0.36–2.57)). Conclusions
Grip strength is inversely associated with mortality risk in older adults, and this association is independent of age, nutritional status, number of prescribed drugs, number of chronic diseases and level of physical activity. The association between muscular strength and all-cause mortality tended to be stronger in women. It seems to be particularly important for the weakest to enhance their levels of muscular strength in order to reduce the risk of dying early.
Background:
Impairment in aerobic fitness is a potential modifiable risk factor for postoperative complications. In this randomized controlled trial, we hypothesized that a high-intensity interval training (HIIT) program enhances cardiorespiratory fitness before lung cancer surgery and therefore reduces the risk of postoperative complications.
Methods:
Patients with operable lung cancer were randomly assigned to usual care (UC, N=77) or preoperative rehabilitation based on HIIT (Rehab, N=74). Maximal cardiopulmonary exercise testing and the six-minute walk test were performed twice before surgery. The primary outcome measure was a composite of death and in-hospital postoperative complications.
Results:
Groups were well balanced in terms of patient characteristics. During the preoperative waiting period (median 25 days), the peak oxygen consumption (peakVO2) and the six-minute walking distance increased (respectively, median +15 % [IQ 25-75%, +9 to +22%] P=0.003 and +15% [IQ25-75, +8 to +28%], P<0.001) in the Rehab group whereas VO2peak declined in the UC group (median -8% [IQ25-75, -16 to 0%], P=0.005). The primary endpoint did not differ significantly between the two groups: 27 of the 74 patients (35.5%) in the Rehab group and 39 of 77 patients (50.6%) in the UC group developed at least one postoperative complication (P=0.080). Noteworthy, the incidence of pulmonary complications was lower in the Rehab compared with the UC group (23% vs 44%, P=0.018), owing to a significant reduction in atelectasis (12.2% vs 36.4%, P<0.001) and this was accompanied by a shorter length of stay in the postanesthesia care unit (median -7 hours, IQ25-75% -4 to -10).
Conclusions:
In this RCT, preoperative HIIT resulted in significant improvement in aerobic performances but failed to reduce early complications after lung cancer resection.
Few studies have investigated long-term changes in cardiorespiratory fitness (CRF), defined by indirect measures of CRF, and all-cause mortality. We aimed to investigate whether long-term change in CRF, as assessed by the gold standard method of respiratory gas exchange during exercise, is associated with all-cause mortality. A population-based sample of 579 men aged 42 to 60 years with no missing data at baseline examination (V1) and at reexamination at 11 years (V2) were included. Maximal oxygen uptake (VO2max) was measured at both visits using respiratory gas exchange during maximal exercise testing, and the difference (ΔVO2max) was calculated as VO2max (V2) − VO2max (V1). Deaths were ascertained annually using national death certificates during 15 years of follow-up after V2. The mean ΔVO2max was −5.2 mL/min*kg. During median follow-up of 13.3 years (interquartile range, 12.5-14.0 years), 123 deaths (21.2%) were recorded. In a multivariate analysis adjusted for baseline age, VO2max, systolic blood pressure, smoking status, low- and high-density lipoprotein cholesterol and triglyceride levels, C-reactive protein level, body mass index, alcohol consumption, physical activity, socioeconomic status, and history of type 2 diabetes mellitus and ischemic heart disease, a 1 mL/min*kg higher ΔVO2max was associated with a 9% relative risk reduction of all-cause mortality (hazard ratio, 0.91; 95% CI, 0.87-0.95). This study suggested that in this population, long-term CRF reduction was associated with an increased risk of mortality, emphasizing the importance of maintaining good CRF over the decades.
Background:
Considerable debate continues to surround the concept of mitochondrial dysfunction in aging muscle. We tested the overall hypothesis that age per se does not influence mitochondrial function and markers of mitochondria quality control, that is, expression of fusion, fission, and autophagy proteins. We also investigated the influence of cardiorespiratory fitness (VO2max) and adiposity (body mass index) on these associations.
Methods:
Percutaneous biopsies of the vastus lateralis were obtained from sedentary young (n = 14, 24±3 years), middle-aged (n = 24, 41±9 years) and older adults (n = 20, 78±5 years). A physically active group of young adults (n = 10, 27±5 years) was studied as a control. Mitochondrial respiration was determined in saponin permeabilized fiber bundles. Fusion, fission and autophagy protein expression was determined by Western blot. Cardiorespiratory fitness was determined by a graded exercise test.
Results:
Mitochondrial respiratory capacity and expression of fusion (OPA1 and MFN2) and fission (FIS1) proteins were not different among sedentary groups despite a wide age range (21 to 88 years). Mitochondrial respiratory capacity and fusion and fission proteins were, however, negatively associated with body mass index, and mitochondrial respiratory capacity was positively associated with cardiorespiratory fitness. The young active group had higher respiration, complex I and II respiratory control ratios, and expression of fusion and fission proteins. Finally, the expression of fusion, fission, and autophagy proteins were linked with mitochondrial respiration.
Conclusions:
Mitochondrial respiration and markers of mitochondrial dynamics (fusion and fission) are not associated with chronological age per se, but rather are more strongly associated with body mass index and cardiorespiratory fitness.
Purpose
Following colorectal cancer diagnosis and anti-cancer therapy, declines in cardiorespiratory fitness and body composition lead to significant increases in morbidity and mortality. There is increasing interest within the field of exercise oncology surrounding potential strategies to remediate these adverse outcomes. This study compared 4 weeks of moderate-intensity exercise (MIE) and high-intensity exercise (HIE) training on peak oxygen consumption (V̇O2peak) and body composition in colorectal cancer survivors.
Methods
Forty seven post-treatment colorectal cancer survivors (HIE = 27 months post-treatment; MIE = 38 months post-treatment) were randomised to either HIE [85–95 % peak heart rate (HRpeak)] or MIE (70 % HRpeak) in equivalence with current physical activity guidelines and completed 12 training sessions over 4 weeks.
Results
HIE was superior to MIE in improving absolute (p = 0.016) and relative (p = 0.021) V̇O2peak. Absolute (+0.28 L.min−1, p < 0.001) and relative (+3.5 ml.kg−1.min−1, p < 0.001) V̇O2 peak were increased in the HIE group but not the MIE group following training. HIE led to significant increases in lean mass (+0.72 kg, p = 0.002) and decreases in fat mass (−0.74 kg, p < 0.001) and fat percentage (−1.0 %, p < 0.001), whereas no changes were observed for the MIE group. There were no severe adverse events.
Conclusions
In response to short-term training, HIE is a safe, feasible and efficacious intervention that offers clinically meaningful improvements in cardiorespiratory fitness and body composition for colorectal cancer survivors.
Implications for Cancer Survivors
HIE appears to offer superior improvements in cardiorespiratory fitness and body composition in comparison to current physical activity recommendations for colorectal cancer survivors and therefore may be an effective clinical utility following treatment.
Muscular strength, an important component of physical fitness, has an independent role in the prevention of chronic diseases whereas muscular weakness is strongly related to functional limitations and physical disability. Our purpose was to investigate the role of muscular strength as a predictor of mortality in health and disease. We conducted a systematic search in EMBASE and MEDLINE (1980-2014) looking for the association between muscular strength and mortality risk (all-cause and cause-specific mortality). Selected publications included 23 papers (15 epidemiological and 8 clinical studies). Muscular strength was inversely and independently associated with all-cause mortality even after adjusting for several confounders including the levels of physical activity or even cardiorespiratory fitness. The same pattern was observed for cardiovascular mortality; however more research is needed due to the few available data. The existed studies failed to show that low muscular strength is predictive of cancer mortality. Furthermore, a strong and inverse association of muscular strength with all-cause mortality has also been confirmed in several clinical populations such as cardiovascular disease, peripheral artery disease, cancer, renal failure, chronic obstructive pulmonary disease, rheumatoid arthritis and patients with critical illness. However, future studies are needed to further establish the current evidence and to explore the exact independent mechanisms of muscular strength in relation to mortality. Muscular strength as a modifiable risk factor would be of great interest from a public health perspective.
Copyright © 2015 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.
Background:
Mortality risk decreases beyond a certain fitness level. However, precise definition of this threshold is elusive and varies with age. Thus, fitness-related mortality risk assessment is difficult.
Methods and results:
We studied 18 102 male veterans (8305 blacks and 8746 whites). All completed an exercise test between 1986 and 2011 with no evidence of ischemia. We defined the peak metabolic equivalents (METs) level associated with no increase in all-cause mortality risk (hazard ratio, 1.0) for the age categories of <50, 50 to 59, 60 to 69, and ≥70 years. We used this as the threshold group to form additional age-specific fitness categories based on METs achieved below and above it: least-fit (>2 METs below threshold; n=1692), low-fit (2 METs below threshold; n=4884), moderate-fit (2 METs above threshold; n=4646), fit (2.1-4 METs above threshold; n=1874), and high-fit (>4 METs above threshold; n=1301) categories. Multivariable Cox models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality across fitness categories. During follow-up (median=10.8 years), 5102 individuals died. Mortality risk for the cohort and each age category increased for the least-fit and low-fit categories (HR, 1.51; 95% CI, 1.37-1.66; and HR, 1.21; 95% CI, 1.12-1.30, respectively) and decreased for the moderate-fit; fit and high-fit categories (HR, 0.71; 95% CI, 0.65-0.78; HR, 0.63; 95% CI, 0.56-0.78; and HR, 0.49; 95% CI, 0.41-0.58, respectively). The trends were similar for 5- and 10-year mortality risk.
Conclusion:
We defined age-specific exercise capacity thresholds to guide assessment of mortality risk in individuals undergoing a clinical exercise test.
Purpose:
The aim of this work was to investigate cardiorespiratory fitness in breast cancer patients at different time points of anti-cancer treatment.
Patients and methods:
Non-metastatic breast cancer patients (n = 222, mean age 55 years) were categorized into four subgroups according to their treatment status. Cardiopulmonary exercise testing (CPET) was used to measure patients' cardiorespiratory fitness, including oxygen delivery and metabolic muscle function. Testing was performed by bicycle ergometry, and maximal oxygen uptake (VO2peak) was measured. Heart rate during exercise at 50 watts (HR50) was assessed as a cardiocirculatory parameter and ventilatory threshold (VT) was used as an indicator of the O2 supply to muscle. Analysis of covariance was used to estimate the impact of different cancer treatments on cardiorespiratory fitness with adjustment for clinical factors.
Results:
Submaximal measures were successfully assessed in 220 (99%) and 200 (90%) patients for HR50 and VT, while criteria for maximal exercise testing were met by 176 patients (79%), respectively. The mean VO2peak was 20.6 ± 6.7 ml/kg/min, mean VT 10.7 ± 2.9 ml/min/kg and mean HR50 112 ± 16 beats/min. Chemotherapy was significantly associated with decreased VO2peak, with significantly lower adjusted mean VO2peak among patients post adjuvant chemotherapy compared to patients with no chemotherapy or those who just started chemotherapy regime (all p < 0.01). Patients post adjuvant chemotherapy reached only 63% of the VO2peak level expected for their age- and BMI-category (mean VO2peak 15.5 ± 4.8 ml/kg/min). Similarly, HR50 was significantly associated with treatment. However, VT was not associated with treatment.
Conclusion:
Breast cancer patients have marked and significantly impaired cardiopulmonary function during and after chemotherapy. Hereby, chemotherapy appears to impair cardiorespiratory fitness by influencing the oxygen delivery system rather than impacting metabolic muscle function. Our findings underline the need of exercise training in breast cancer patients to counteract the loss of cardiorespiratory fitness during the anti-cancer treatment.
Muscle wasting and cachexia are the ultimate consequence of aging and a variety of acute and chronic illnesses. Significant efforts are made by many stakeholders to develop effective therapies. An important aspect of successful therapeutic development research is a common nomenclature for effective communication between researchers and clinicians, to the public, and also with regulatory bodies. Despite several efforts to develop consensus definitions for cachexia and sarcopenia, including such new terms for muscle wasting as myopenia, a common conceptual approach and acceptable vocabulary and classification system are yet to be established. Notwithstanding the potential need to translate such disease definitions and terminologies into different languages, we advocate the use of the term "muscle wasting" as the unifying entity that represents the single most common disease process across a large spectrum of cachexia and in sarcopenia-associated disorders. In this paper, we outline a first proposal for the disease nomenclature and classification of "Muscle Wasting Diseases." This concept can be applied in acute and chronic disease settings. It is pertinent for wasting diseases, cachexia, and sarcopenia of any severity and due to any underlying illness. The concept of muscle wasting disease underscores the most common denominator of the underlying wasting processes, i.e., muscle wasting, without ignoring the advanced disease states that are also accompanied by fat tissue wasting. The term muscle wasting disease is easily understood by both the scientific community and the lay public. This may promote its general use and efforts to heighten education and awareness in the field.
BACKGROUND: Pulmonary rehabilitation is recognized as a core component of the management of individuals with chronic respiratory disease. Since the 2006 American Thoracic Society (ATS)/European Respiratory Society (ERS) Statement on Pulmonary Rehabilitation, there has been considerable growth in our knowledge of its efficacy and scope.
PURPOSE: The purpose of this Statement is to update the 2006 document, including a new definition of pulmonary rehabilitation and highlighting key concepts and major advances in the field.
METHODS: A multidisciplinary committee of experts representing the ATS Pulmonary Rehabilitation Assembly and the ERS Scientific Group 01.02, "Rehabilitation and Chronic Care," determined the overall scope of this update through group consensus. Focused literature reviews in key topic areas were conducted by committee members with relevant clinical and scientific expertise. The final content of this Statement was agreed on by all members.
RESULTS: An updated definition of pulmonary rehabilitation is proposed. New data are presented on the science and application of pulmonary rehabilitation, including its effectiveness in acutely ill individuals with chronic obstructive pulmonary disease, and in individuals with other chronic respiratory diseases. The important role of pulmonary rehabilitation in chronic disease management is highlighted. In addition, the role of health behavior change in optimizing and maintaining benefits is discussed.
CONCLUSIONS: The considerable growth in the science and application of pulmonary rehabilitation since 2006 adds further support for its efficacy in a wide range of individuals with chronic respiratory disease.
Endurance exercise training studies frequently show modest changes in VO2max with training and very limited responses in some subjects. By contrast, studies using interval training (IT) or combined IT and continuous training (CT) have reported mean increases in VO2max of up to ∼1.0 L · min(-1). This raises questions about the role of exercise intensity and the trainability of VO2max. To address this topic we analyzed IT and IT/CT studies published in English from 1965-2012. Inclusion criteria were: 1)≥3 healthy sedentary/recreationally active humans <45 yrs old, 2) training duration 6-13 weeks, 3) ≥3 days/week, 4) ≥10 minutes of high intensity work, 5) ≥1∶1 work/rest ratio, and 6) results reported as mean ± SD or SE, ranges of change, or individual data. Due to heterogeneity (I(2) value of 70), statistical synthesis of the data used a random effects model. The summary statistic of interest was the change in VO2max. A total of 334 subjects (120 women) from 37 studies were identified. Participants were grouped into 40 distinct training groups, so the unit of analysis was 40 rather than 37. An increase in VO2max of 0.51 L ·min(-1) (95% CI: 0.43 to 0.60 L · min(-1)) was observed. A subset of 9 studies, with 72 subjects, that featured longer intervals showed even larger (∼0.8-0.9 L · min(-1)) changes in VO2max with evidence of a marked response in all subjects. These results suggest that ideas about trainability and VO2max should be further evaluated with standardized IT or IT/CT training programs.
We examined whole body aerobic capacity and myocellular markers of oxidative metabolism in lifelong endurance athletes (n=9, 81±1 y, 68±3 kg, BMI=23±1 kg/m(2)) and age-matched, healthy, untrained men (n=6; 82±1 y, 77±5 kg, BMI=26±1 kg/m(2)). The endurance athletes were cross-country skiers, including a former Olympic champion and several national/regional champions, with a history of aerobic exercise and participation in endurance events throughout their lives. Each subject performed a maximal cycle test to assess aerobic capacity (VO(2)max). Subjects had a resting vastus lateralis muscle biopsy to assess oxidative enzymes (citrate synthase and βHAD) and molecular (mRNA) targets associated with mitochondrial biogenesis (PGC-1α and Tfam). The octogenarian athletes had a higher (P<0.05) absolute (2.6±0.1 vs. 1.6±0.1 L•min(-1)) and relative (38±1 vs. 21±1 ml•kg(-1)•min(-1)) VO(2)max, ventilation (79±3 vs. 64±7 L•min(-1)), heart rate (160±5 vs. 146±8 b•min(-1)), and final workload (182±4 vs. 131±14 watts). Skeletal muscle oxidative enzymes were 54% (citrate synthase) and 42% (βHAD) higher (P<0.05) in the octogenarian athletes. Likewise, basal PGC-1α and Tfam mRNA were 135% and 80% greater (P<0.05) in the octogenarian athletes. To our knowledge, the VO(2)max of the lifelong endurance athletes is the highest recorded in humans >80 y of age and comparable to non-endurance trained men 40 years younger. The superior cardiovascular and skeletal muscle health profile of the octogenarian athletes provides a large functional reserve above the aerobic frailty threshold and is associated with lower risk for disability and mortality.
To systematically evaluate the effects of physical activity in adult patients after completion of main treatment related to cancer.
Meta-analysis of randomised controlled trials with data extraction and quality assessment performed independently by two researchers.
Pubmed, CINAHL, and Google Scholar from the earliest possible year to September 2011. References from meta-analyses and reviews.
Randomised controlled trials that assessed the effects of physical activity in adults who had completed their main cancer treatment, except hormonal treatment.
There were 34 randomised controlled trials, of which 22 (65%) focused on patients with breast cancer, and 48 outcomes in our meta-analysis. Twenty two studies assessed aerobic exercise, and four also included resistance or strength training. The median duration of physical activity was 13 weeks (range 3-60 weeks). Most control groups were considered sedentary or were assigned no exercise. Based on studies on patients with breast cancer, physical activity was associated with improvements in insulin-like growth factor-I, bench press, leg press, fatigue, depression, and quality of life. When we combined studies on different types of cancer, we found significant improvements in body mass index (BMI), body weight, peak oxygen consumption, peak power output, distance walked in six minutes, right handgrip strength, and quality of life. Sources of study heterogeneity included age, study quality, study size, and type and duration of physical activity. Publication bias did not alter our conclusions.
Physical activity has positive effects on physiology, body composition, physical functions, psychological outcomes, and quality of life in patients after treatment for breast cancer. When patients with cancer other than breast cancer were also included, physical activity was associated with reduced BMI and body weight, increased peak oxygen consumption and peak power output, and improved quality of life.
The purpose of this Position Stand is to provide guidance to professionals who counsel and prescribe individualized exercise to apparently healthy adults of all ages. These recommendations also may apply to adults with certain chronic diseases or disabilities, when appropriately evaluated and advised by a health professional. This document supersedes the 1998 American College of Sports Medicine (ACSM) Position Stand, "The Recommended Quantity and Quality of Exercise for Developing and Maintaining Cardiorespiratory and Muscular Fitness, and Flexibility in Healthy Adults." The scientific evidence demonstrating the beneficial effects of exercise is indisputable, and the benefits of exercise far outweigh the risks in most adults. A program of regular exercise that includes cardiorespiratory, resistance, flexibility, and neuromotor exercise training beyond activities of daily living to improve and maintain physical fitness and health is essential for most adults. The ACSM recommends that most adults engage in moderate-intensity cardiorespiratory exercise training for ≥30 min·d on ≥5 d·wk for a total of ≥150 min·wk, vigorous-intensity cardiorespiratory exercise training for ≥20 min·d on ≥3 d·wk (≥75 min·wk), or a combination of moderate- and vigorous-intensity exercise to achieve a total energy expenditure of ≥500-1000 MET·min·wk. On 2-3 d·wk, adults should also perform resistance exercises for each of the major muscle groups, and neuromotor exercise involving balance, agility, and coordination. Crucial to maintaining joint range of movement, completing a series of flexibility exercises for each the major muscle-tendon groups (a total of 60 s per exercise) on ≥2 d·wk is recommended. The exercise program should be modified according to an individual's habitual physical activity, physical function, health status, exercise responses, and stated goals. Adults who are unable or unwilling to meet the exercise targets outlined here still can benefit from engaging in amounts of exercise less than recommended. In addition to exercising regularly, there are health benefits in concurrently reducing total time engaged in sedentary pursuits and also by interspersing frequent, short bouts of standing and physical activity between periods of sedentary activity, even in physically active adults. Behaviorally based exercise interventions, the use of behavior change strategies, supervision by an experienced fitness instructor, and exercise that is pleasant and enjoyable can improve adoption and adherence to prescribed exercise programs. Educating adults about and screening for signs and symptoms of CHD and gradual progression of exercise intensity and volume may reduce the risks of exercise. Consultations with a medical professional and diagnostic exercise testing for CHD are useful when clinically indicated but are not recommended for universal screening to enhance the safety of exercise.
The time-course and mechanisms of adaptation of cardiorespiratory fitness were examined in 8 older (O) (68 +/- 7 yr old) and 8 young (Y) (23 +/- 5 yr old) men pretraining and at 3, 6, 9, and 12 wk of training. Training was performed on a cycle ergometer three times per week for 45 min at approximately 70% of maximal oxygen uptake (Vo(2 max)). Vo(2 max) increased within 3 wk with further increases observed posttraining in both O (+31%) and Y (+18%), (P < 0.05). Maximal cardiac output (Q(max), open-circuit acetylene) and stroke volume were higher in O and Y after 3 wk with further increases after 9 wk of training (P < 0.05). Maximal arterial-venous oxygen difference (a-vO(2 diff)) was higher at weeks 3 and 6 and posttraining compared with pretraining in O and Y (P < 0.05). In O, approximately 69% of the increase in Vo(2 max) from pre- to posttraining was explained by an increased Q(max) with the remaining approximately 31% explained by a widened a-vO(2 diff). This proportion of Q and a-vO(2 diff) contributions to the increase in Vo(2 max) was consistent throughout testing in O. In Y, 56% of the pre- to posttraining increase in Vo(2 max) was attributed to a greater Q(max) and 44% to a widened a-vO(2 diff). Early adaptations (first 3 wk) mainly relied on a widened maximal a-vO(2 diff) (approximately 66%) whereas further increases in Vo(2 max) were exclusively explained by a greater Q(max). In conclusion, with short-term training O and Y significantly increased their Vo(2 max); however, the proportion of Vo(2 max) increase explained by Q(max) and maximal a-vO(2 diff) throughout training showed a different pattern by age group.
Background:
Aging is associated with loss in both muscle mass and the metabolic quality of skeletal muscle. A major part of these changes is associated with an age-related decrease in the level of physical activity and may be counteracted by endurance training (ET) and resistance training (RT).
Objective:
Since both muscle strength and aerobic power decrease with age, we investigated what form of training might be best for improvements in physical performance in the elderly. In detail, we wanted to know whether systematic ET can augment muscle strength and/or whether systematic RT can augment the aerobic power of healthy elderly adults.
Methods:
Forty-two volunteers (32 women, 10 men) were recruited for the study and randomized into three groups: 13 persons undertook a continuous 6-month ET program, 15 undertook a continuous 6-month RT program and 14 served as a control group. All persons performed a cycling test to measure aerobic power (VO(2max)) and maximum workload (W(max)) before and after the training period. Maximum strength was determined from one repetition maximum (1-RM).
Results:
After 6 months of RT, maximum strength increased by an average of 15% for leg press (P < 0.01), 25% for bench press (P < 0.01) and 30% for bench pull (P < 0.001); ET showed no effect on maximum strength except for the 1-RM in bench pull. Aerobic power improved by 6% in the ET group and by 2.5% in the RT group, neither of which was significant. Maximum workload improved significantly by 31% in the ET group (P < 0.001) and by 6% in the RT group (P = 0.05). ET resulted in a significant 5.3% reduction of body fat (P < 0.05), whereas only RT increased lean body mass by 1.0 +/- 0.5 kg.
Conclusion:
RT leads to a genuine increase in lean body mass and muscle strength in healthy elderly adults and is therefore the best method for treatment of amyotrophia. ET appears to be the most efficacious training mode for maintaining and improving maximum aerobic power in the elderly and should be viewed as a complement to RT. The loading intensity to promote hypertrophy should approach 60-80% of 1-RM with an exercise volume ranging from 3 to 6 sets per muscle group per week of 10-15 repetitions per exercise. ET should be performed on two days per week controlled by a heart rate according to 60% of VO(2max) and an exercise volume ranging from 30 to 60 minutes per week.
Exercise capacity is known to be an important prognostic factor in patients with cardiovascular disease, but it is uncertain whether it predicts mortality equally well among healthy persons. There is also uncertainty regarding the predictive power of exercise capacity relative to other clinical and exercise-test variables.
We studied a total of 6213 consecutive men referred for treadmill exercise testing for clinical reasons during a mean (+/-SD) of 6.2+/-3.7 years of follow-up. Subjects were classified into two groups: 3679 had an abnormal exercise-test result or a history of cardiovascular disease, or both, and 2534 had a normal exercise-test result and no history of cardiovascular disease. Overall mortality was the end point.
There were a total of 1256 deaths during the follow-up period, resulting in an average annual mortality of 2.6 percent. Men who died were older than those who survived and had a lower maximal heart rate, lower maximal systolic and diastolic blood pressure, and lower exercise capacity. After adjustment for age, the peak exercise capacity measured in metabolic equivalents (MET) was the strongest predictor of the risk of death among both normal subjects and those with cardiovascular disease. Absolute peak exercise capacity was a stronger predictor of the risk of death than the percentage of the age-predicted value achieved, and there was no interaction between the use or nonuse of beta-blockade and the predictive power of exercise capacity. Each 1-MET increase in exercise capacity conferred a 12 percent improvement in survival.
Exercise capacity is a more powerful predictor of mortality among men than other established risk factors for cardiovascular disease.
During the winter and spring of 1952-53 a survey of hemoglobin values was made in Halifax among 1308 male subjects 6 to 98 years of age, and 1424 female subjects 6 to 94 years of age.
Among children 6 to 14 years old the values increased from about 13 to about 14 Gm. per 100 ml. of blood, and there were essentially no differences between the sexes. The average value for both the boys and the girls was 13.5 Gm.
In girls between 14 and 20 years of age the hemoglobin values decreased slightly, reaching about 13 Gm. per 100 ml. In boys of corresponding ages there was an increase to about 15 Gm. In both sexes these values were attained at about 20 years of age, and remained characteristic of the third decade of life. They were essentially the lowest and the highest shown respectively by the female and the male subjects of any age group.
Hemoglobin values in men between 20 and 60 years of age were typically 14.5 to 15 Gm. per 100 ml., the higher values tending to occur among the younger men. After the fifth decade there were progressive and marked decreases to an average of 12.4 in men between 80 and 90 years of age.
In women from 20 years of age onward the average hemoglobin values remained near 13 Gm. per 100 ml.
Physiological functional capacity (PFC) is defined here as the ability to perform the physical tasks of daily life and the ease with which these tasks can be performed. For the past decade, we have sought to determine the effect of primary (healthy) adult human aging on PFC and the potential modulatory influences of gender and habitual aerobic exercise status on this process by studying young adult and Masters athletes. An initial approach to determining the effects of aging on PFC involved investigating changes in peak exercise performance with age in highly trained and competitive athletes. PFC, as assessed by running and swimming performance, decreased only modestly until age 60-70 yr but declined exponentially thereafter. A progressive reduction in maximal O2 consumption (V(O2 max)) appears to be the primary physiological mechanism associated with declines in endurance running performance with advancing age, along with a reduction in the exercise velocity at lactate threshold. Because V(O2 max) is important in mediating age-related reductions in exercise performance and PFC, we then investigated the modulatory influence of habitual aerobic exercise status on the rate of decline in V(O2 max) with age. Surprisingly, as a group, endurance-trained adults appear to undergo greater absolute rates of decline in V(O2 max) with advancing age compared with healthy sedentary adults. This appears to be mediated by a baseline effect (higher V(O2 max) as young adults) and/or a marked age-related decline in exercise training volume and intensity (stimulus) in endurance-trained adults. Thus the ability to maintain habitual physical activity levels with advancing age appears to be a critical determinant of changes in PFC in part via modulation of maximal aerobic capacity.
This study examined the effects of short-term endurance training (ET) on the left ventricular (LV) adaptation and functional response to a series of exercise challenges with increasing intensity. Eight untrained men, with a mean age of 19.4 +/- 0.5 (SE) yr, were studied before and after 6 days of ET consisting of cycling 2 h/day at 65% peak aerobic power (VO2max). LV ejection fraction and LV volumes were assessed by radionuclide angiography at rest and during exercise at three uninterrupted successive work rates corresponding to 53, 68, and 83% of VO2max, each lasting 20 min. ET produced a calculated plasma volume expansion of 11.4 +/- 2.2% (P < 0.05). The increase in plasma volume was accompanied by an increase in VO2max from 45.9 +/- 1.9 to 49.0 +/- 1.0 ml x kg(-1) x min(-1) (P < 0.01) and a decrease in maximal heart rate (197 +/- 2.3 to 188 +/- 1.0 beats/min; P < 0.01). Resting LV function was not changed, although there was a trend for higher stroke volumes (SVs) and improvement in the rapid filling phase of diastole (P = 0.08). Training induced an increase in exercise SV by 10.4, 10.2, and 7% at 53, 68, and 83% VO2max, respectively (P < 0.01). These changes were secondary to increases in end-diastolic volume, which increased significantly at each exercise work rate following training (139 +/- 6 to 154 +/- 6 ml at 53% VO2max, and from 136 +/- 5 to 156 +/- 5 ml at 83% VO2max; P < 0.01). End-systolic volumes were unchanged after ET. A significant bradycardia was observed both at rest (decreasing 7%) and exercise (decreasing 10.4%). LV ejection fraction during exercise was increased slightly by training, reaching significance at the highest work rate, after 60 min of exercise. (P < 0.05). Cardiac output was higher following training at the highest workload (20.8 +/- 2.2 vs. 22.9 +/- 3.1 l/min; P < 0.01). These data indicate that short-term training elicits rapid adaptation to the LV functional response exercise, with increases in SV being secondary to a Frank-Starling effect with minor changes in contractile performance. This produced a volume-induced bradycardia and increase in LV filling, which may be of benefit during prolonged exercise.
Exercise training reduces the symptoms of chronic heart failure. Which exercise intensity yields maximal beneficial adaptations is controversial. Furthermore, the incidence of chronic heart failure increases with advanced age; it has been reported that 88% and 49% of patients with a first diagnosis of chronic heart failure are >65 and >80 years old, respectively. Despite this, most previous studies have excluded patients with an age >70 years. Our objective was to compare training programs with moderate versus high exercise intensity with regard to variables associated with cardiovascular function and prognosis in patients with postinfarction heart failure.
Twenty-seven patients with stable postinfarction heart failure who were undergoing optimal medical treatment, including beta-blockers and angiotensin-converting enzyme inhibitors (aged 75.5+/-11.1 years; left ventricular [LV] ejection fraction 29%; VO2peak 13 mL x kg(-1) x min(-1)) were randomized to either moderate continuous training (70% of highest measured heart rate, ie, peak heart rate) or aerobic interval training (95% of peak heart rate) 3 times per week for 12 weeks or to a control group that received standard advice regarding physical activity. VO2peak increased more with aerobic interval training than moderate continuous training (46% versus 14%, P<0.001) and was associated with reverse LV remodeling. LV end-diastolic and end-systolic volumes declined with aerobic interval training only, by 18% and 25%, respectively; LV ejection fraction increased 35%, and pro-brain natriuretic peptide decreased 40%. Improvement in brachial artery flow-mediated dilation (endothelial function) was greater with aerobic interval training, and mitochondrial function in lateral vastus muscle increased with aerobic interval training only. The MacNew global score for quality of life in cardiovascular disease increased in both exercise groups. No changes occurred in the control group.
Exercise intensity was an important factor for reversing LV remodeling and improving aerobic capacity, endothelial function, and quality of life in patients with postinfarction heart failure. These findings may have important implications for exercise training in rehabilitation programs and future studies.
Heart Failure (HF) results in high healthcare costs and burdens for the United States both in respects to hospitalizations, therapies, and associated disability. The relative proportion of HF with preserved ejection fraction (HFpEF) compared with HF with reduced ejection fraction (HFrEF) is on the rise; HFpEF has already become the dominant form of HF and it continues to increase. The serious implications of these trends are compounded by a dearth of effective HFpEF therapies. While low physical activity, low cardiorespiratory fitness (CRF), and obesity, are risk factors for HF in general, they particularly predispose to HFpEF. Thus, weight loss and exercise that leads to improved CRF may constitute important opportunities for effective intervention. In this review, we discuss the interplay between physical inactivity, CRF, and obesity in the development of HF, particularly HFpEF, and highlight the current evidence on weight loss and exercise as preventive and therapeutic opportunities.
Objectives:
To systematically examine the relative magnitude and predictors of responses to exercise training in older adult with heart failure (HF) with reduced ejection fraction (HFrEF), and preserved EF (HFpEF).
Design:
Secondary analysis of a randomized controlled trial.
Setting:
Outpatient cardiac rehabilitation program.
Participants:
Individuals with HF (24 HFrEF, 24 HFpEF) who underwent supervised exercise training.
Measurements:
The study included individual-level data from the exercise training arms of a randomized controlled trial that evaluated the effect of 16 weeks of supervised moderate-intensity endurance exercise training in older adults with chronic, stable HFpEF and HFrEF. Changes in peak oxygen uptake (VO2peak ) in response to supervised training in individuals with HFpEF were compared with that of individuals with HFrEF. The significant clinical predictors of changes in VO2peak with exercise training were assessed using univariate and multivariate regression models.
Results:
Training-related improvement in VO2peak was higher in participants with HFpEF than in those with HFrEF (change: 18.7 ± 17.6% vs -0.3 ± 15.4%, P < .001). In univariate analysis, echocardiographic abnormalities in left ventricular structure and function and lower body mass index were associated with blunted response of VO2peak with exercise training. In multivariate regression analysis using stepwise selection, submaximal exercise systolic blood pressure, and resting early deceleration time were independent predictors of change in VO2peak .
Conclusion:
The change in VO2peak in response to endurance exercise training in older adults with HF differs significantly according to HF subtype, with greater VO2peak improvement in HFpEF than HFrEF. These results suggest that the current Centers for Medicare and Medicaid Services policy excluding individuals with HFpEF from reimbursement from cardiac rehabilitation may need to be revisited.
Cardiorespiratory fitness (CRF) has been one of the most widely examined physiological variables, particularly as it relates to functional capacity and human performance. Over the past three decades, CRF has emerged as a strong, independent predictor of all-cause and disease-specific mortality. The evidence supporting the prognostic use of CRF is so powerful that the American Heart Association recently advocated for the routine assessment of CRF as a clinical vital sign. Interestingly, the continuity of evidence of the inverse relationship between CRF and mortality over the past decade exists despite a wide variation of methods used to assess CRF in these studies, ranging from the gold-standard method of directly measured maximal oxygen uptake (VO2max) during cardiopulmonary exercise testing to estimation from exercise tests and non-exercise prediction equations. This review highlights new knowledge and the primary advances since 2009, with specific reference to the impact variations in CRF have on all-cause and disease-specific mortality.
In this review we argue that several key features of maximal oxygen uptake (VO2max) should underpin discussions about the biological and reductionist determinants of its inter-individual variability: 1) Training induced increases in VO2max are largely facilitated by expansion of red blood cell volume and an associated improvement in stroke volume, which also adapts independent of changes in red blood cell volume. These general concepts are also informed by cross sectional studies in athletes that have very high values for VO2max. Therefore, 2) variations in VO2max improvements with exercise training are also likely related to variations in these physiological determinants. 3) All previously untrained individuals will respond to endurance exercise training in terms of improvements in VO2max provided the stimulus exceeds a certain volume and/or intensity. Thus genetic analysis and/or reductionist studies performed to understand or predict such variations might focus specifically on DNA variants or other molecular phenomena of relevance to these physiological pathways. This article is protected by copyright. All rights reserved.
Objective:
Emerging research suggests that aerobic-based physical activity may help to promote survival among chronic obstructive pulmonary disease patients. However, the extent to which engagement in resistance training on survival among chronic obstructive pulmonary disease patients is relatively unknown. Therefore, the purpose of this study was to examine the independent associations of muscle strengthening activities on all-cause mortality among a national sample of U.S. adults with chronic obstructive pulmonary disease. We hypothesize that muscle strengthening activities will be inversely associated with all-cause mortality.
Methods:
Data from the 2003-2006 NHANES were employed, with follow-up through 2011. Aerobic-based physical activity was objectively measured via accelerometry, muscle strengthening activities engagement was assessed via self-report, and chronic obstructive pulmonary disease was assessed via physician-diagnosis.
Results:
Analysis included 385 adults (20 + yrs) with chronic obstructive pulmonary disease, who represent 13.3 million chronic obstructive pulmonary disease patients in the USA. The median follow-up period was 78 months (IQR=64-90), with 82 chronic obstructive pulmonary disease patients dying during this period. For a two muscle strengthening activity sessions/week increase (consistent with national guidelines), chronic obstructive pulmonary disease patients had a 29% reduced risk of all-cause mortality (HR=0.71; 95% CI: 0.51-0.99; P = 0.04).
Conclusion:
Participation in muscle strengthening activities, independent of aerobic-based physical activity and other potential confounders, is associated with greater survival among chronic obstructive pulmonary disease patients.
Exercise training enhances physical performance and confers health benefits, largely through adaptations in skeletal muscle. Mitochondrial adaptation, encompassing coordinated improvements in quantity (content) and quality (structure and function), is increasingly recognized as a key factor in the beneficial outcomes of exercise training. Exercise training has long been known to promote mitochondrial biogenesis, but recent work has demonstrated that it has a profound impact on mitochondrial dynamics (fusion and fission) and clearance (mitophagy), as well. In this review, we discuss the various mechanisms through which exercise training promotes mitochondrial quantity and quality in skeletal muscle.—Drake, J. C., Wilson, R. J., Yan, Z. Molecular mechanisms for mitochondrial adaptation to exercise training in skeletal muscle. FASEB J. 30, 000–000 (2016). www.fasebj.org
Nutrition and metabolism have been the topic of extensive scientific research in chronic obstructive pulmonary disease (COPD) but clinical awareness of the impact dietary habits, nutritional status and nutritional interventions may have on COPD incidence, progression and outcome is limited. A multidisciplinary Task Force was created by the European Respiratory Society to deliver a summary of the evidence and description of current practice in nutritional assessment and therapy in COPD, and to provide directions for future research. Task Force members conducted focused reviews of the literature on relevant topics, advised by a methodologist. It is well established that nutritional status, and in particular abnormal body composition, is an important independent determinant of COPD outcome. The Task Force identified different metabolic phenotypes of COPD as a basis for nutritional risk profile assessment that is useful in clinical trial design and patient counselling. Nutritional intervention is probably effective in undernourished patients and probably most when combined with an exercise programme. Providing evidence of cost-effectiveness of nutritional intervention is required to support reimbursement and thus increase access to nutritional intervention. Overall, the evidence indicates that a well-balanced diet is beneficial to all COPD patients, not only for its potential pulmonary benefits, but also for its proven benefits in metabolic and cardiovascular risk.
Background
Although running is a popular leisure-time physical activity, little is known about the long-term effects of running on mortality. The dose-response relations between running, as well as the change in running behaviors over time, and mortality remain uncertain.
Objectives
We examined the associations of running with all-cause and cardiovascular mortality risks in 55,137 adults, 18 to 100 years of age (mean age 44 years).
Methods
Running was assessed on a medical history questionnaire by leisure-time activity.
Results
During a mean follow-up of 15 years, 3,413 all-cause and 1,217 cardiovascular deaths occurred. Approximately 24% of adults participated in running in this population. Compared with nonrunners, runners had 30% and 45% lower adjusted risks of all-cause and cardiovascular mortality, respectively, with a 3-year life expectancy benefit. In dose-response analyses, the mortality benefits in runners were similar across quintiles of running time, distance, frequency, amount, and speed, compared with nonrunners. Weekly running even <51 min, <6 miles, 1 to 2 times, <506 metabolic equivalent-minutes, or <6 miles/h was sufficient to reduce risk of mortality, compared with not running. In the analyses of change in running behaviors and mortality, persistent runners had the most significant benefits, with 29% and 50% lower risks of all-cause and cardiovascular mortality, respectively, compared with never-runners.
Conclusions
Running, even 5 to 10 min/day and at slow speeds <6 miles/h, is associated with markedly reduced risks of death from all causes and cardiovascular disease. This study may motivate healthy but sedentary individuals to begin and continue running for substantial and attainable mortality benefits.
Background:
Epidemiologic studies have reported that cardiorespiratory fitness is inversely associated with mortality from cancer. However, the evidence relating cardiorespiratory fitness to cancer mortality has not yet been quantitatively summarized.
Methods:
Following the preferred reporting items for sytematic reviews and meta-analyses (PRISMA) checklist, we conducted a systematic review and meta-analysis of the association between cardiorespiratory fitness and total cancer mortality. Relevant studies were identified through a literature search in PubMed up to August 2013 and by screening reference lists of qualifying articles. Data extraction was carried out independently by both authors and summary risk estimates were obtained using random-effects models.
Results:
Six prospective studies with an overall number of 71 654 individuals and 2002 cases of total cancer mortality were included. The median follow-up time in the studies was 16.4 years. Cardiorespiratory fitness showed a strong, graded, inverse association with total cancer mortality. Using low cardiorespiratory fitness as the reference group, intermediate and high levels of cardiorespiratory fitness were related to statistically significant decreased summary relative risks (RRs) of total cancer mortality of 0.80 [95% confidence interval (CI) 0.67-0.97] and 0.55 (95% CI 0.47-0.65), respectively. Studies that adjusted for adiposity yielded similar results to those that did not adjust for adiposity.
Conclusion:
Increased cardiorespiratory fitness represents a strong predictor of decreased total cancer mortality risk, independent of adiposity.
-We evaluated the individual and joint associations among cardiorespiratory fitness (CRF), body mass index (BMI), and heart failure (HF) mortality as well as the additive effect of increasing number of cardiovascular risk factors on HF mortality in fit versus unfit men.
-44 674 men without a history of cardiovascular disease underwent a baseline examination between 1971-2010. Measures included BMI and CRF quantified as duration of maximal treadmill exercise testing. Participants were divided into age-specific low, moderate, and high CRF categories. Hazard ratios (HRs) were computed with Cox regression analysis. During a mean follow-up of 19.8±10.4 years, 153 HF deaths occurred. Adjusted HRs across high, moderate, and low CRF categories were 1.0, 1.63, and 3.97 respectively, while those of normal, overweight, and obese BMI categories were 1.0, 1.56, and 3.71 respectively (P for trend <0.0001 for each). When grouped into categories of fit and unfit (upper 80% and lower 20% of CRF distribution respectively), HRs were significantly lower in fit compared with unfit men in normal and overweight BMI strata (P<0.002), but not in obese men. Within men matched for number of HF risk factors, fit men had significantly lower HF mortality than unfit men (P<0.02).
-Higher baseline CRF is associated with lower HF mortality risk in men, regardless of the number of HF risk factors present. Men should be counseled on physical activity with the goal of achieving at least a moderate level of CRF, thereby presumably decreasing their risk of HF mortality.
This study sought to elucidate the mechanisms responsible for the benefits of small muscle mass exercise training in patients with chronic heart failure (CHF).
How central cardiorespiratory and/or peripheral skeletal muscle factors are altered with small muscle mass training in CHF is unknown.
We studied muscle structure, and oxygen (O(2)) transport and metabolism at maximal cycle (whole-body) and knee-extensor exercise (KE) (small muscle mass) in 6 healthy controls and 6 patients with CHF who then performed 8 weeks of KE training (both legs, separately) and repeated these assessments.
Pre-training cycling and KE peak leg O(2) uptake (Vo(2peak)) were ~17% and ~15% lower, respectively, in the patients compared with controls. Structurally, KE training increased quadriceps muscle capillarity and mitochondrial density by ~21% and ~25%, respectively. Functionally, despite not altering maximal cardiac output, KE training increased maximal O(2) delivery (~54%), arterial-venous O(2) difference (~10%), and muscle O(2) diffusive conductance (D(M)O(2)) (~39%) (assessed during KE), thereby increasing single-leg Vo(2peak) by ~53%, to a level exceeding that of the untrained controls. Post-training, during maximal cycling, O(2) delivery (~40%), arterial-venous O(2) difference (~15%), and D(M)O(2) (~52%) all increased, yielding an increase in Vo(2peak) of ~40%, matching the controls.
In the face of continued central limitations, clear improvements in muscle structure, peripheral convective and diffusive O(2) transport, and subsequently, O(2) utilization support the efficacy of local skeletal muscle training as a powerful approach to combat exercise intolerance in CHF.
The health benefits of leisure-time physical activity are well known, but whether less exercise than the recommended 150 min a week can have life expectancy benefits is unclear. We assessed the health benefits of a range of volumes of physical activity in a Taiwanese population.
In this prospective cohort study, 416,175 individuals (199,265 men and 216,910 women) participated in a standard medical screening programme in Taiwan between 1996 and 2008, with an average follow-up of 8·05 years (SD 4·21). On the basis of the amount of weekly exercise indicated in a self-administered questionnaire, participants were placed into one of five categories of exercise volumes: inactive, or low, medium, high, or very high activity. We calculated hazard ratios (HR) for mortality risks for every group compared with the inactive group, and calculated life expectancy for every group.
Compared with individuals in the inactive group, those in the low-volume activity group, who exercised for an average of 92 min per week (95% CI 71-112) or 15 min a day (SD 1·8), had a 14% reduced risk of all-cause mortality (0·86, 0·81-0·91), and had a 3 year longer life expectancy. Every additional 15 min of daily exercise beyond the minimum amount of 15 min a day further reduced all-cause mortality by 4% (95% CI 2·5-7·0) and all-cancer mortality by 1% (0·3-4·5). These benefits were applicable to all age groups and both sexes, and to those with cardiovascular disease risks. Individuals who were inactive had a 17% (HR 1·17, 95% CI 1·10-1·24) increased risk of mortality compared with individuals in the low-volume group.
15 min a day or 90 min a week of moderate-intensity exercise might be of benefit, even for individuals at risk of cardiovascular disease.
Taiwan Department of Health Clinical Trial and Research Center of Excellence and National Health Research Institutes.
The aim of this study was to test the hypotheses that 1) skeletal muscles of elderly subjects can adapt to a single endurance exercise bout and 2) endurance trained elderly subjects have higher expression/activity of oxidative and angiogenic proteins in skeletal muscle than untrained elderly people. To investigate this, lifelong endurance trained elderly (ET; n = 8) aged 71.3 ± 3.4 years and untrained elderly subjects (UT; n = 7) aged 71.3 ± 4 years, performed a cycling exercise bout at 75% VO(2max) with vastus lateralis muscle biopsies obtained before (Pre), immediately after exercise (0 h) and at 2 h of recovery. Capillarization was detected histochemically and oxidative enzyme activities were determined on isolated mitochondria. GLUT4, HKII, Cyt c and VEGF protein expression was measured on muscle lysates from Pre-biopsies, phosphorylation of AMPK and P38 on lysates from Pre and 0 h biopsies, while PGC-1α, VEGF, HKII and TFAM mRNA content was determined at all time points. ET had ~40% higher PDH, CS, SDH, α-KG-DH and ATP synthase activities and 27% higher capillarization than UT, reflecting increased skeletal muscle oxidative capacity with lifelong endurance exercise training. In addition, acute exercise increased in UT PGC-1α mRNA 11-fold and VEGF mRNA 4-fold at 2 h of recovery, and AMPK phosphorylation ~5-fold immediately after exercise, relative to Pre, indicating an ability to adapt metabolically and angiogenically to endurance exercise. However, in ET PGC-1α mRNA only increased 5 fold and AMPK phosphorylation ~2-fold, while VEGF mRNA remained unchanged after the acute exercise bout. P38 increased similarly in ET and UT after exercise. In conclusion, the present findings suggest that lifelong endurance exercise training ensures an improved oxidative capacity of skeletal muscle, and that skeletal muscle of elderly subjects maintains the ability to respond to acute endurance exercise.
The purpose of this study was to determine the association between fitness and lifetime risk for cardiovascular disease (CVD).
Higher levels of traditional risk factors are associated with marked differences in lifetime risks for CVD. However, data are sparse regarding the association between fitness and the lifetime risk for CVD.
We followed up 11,049 men who underwent clinical examination at the Cooper Institute in Dallas, Texas, before 1990 until the occurrence of CVD death, non-CVD death, or attainment of age 90 years (281,469 person-years of follow-up, median follow-up 25.3 years, 1,106 CVD deaths). Fitness was measured by the Balke protocol and categorized according to treadmill time into low, moderate, and high fitness, with further stratification by CVD risk factor burden. Lifetime risk for CVD death determined by the National Death Index was estimated for fitness levels measured at ages 45, 55, and 65 years, with non-CVD death as the competing event.
Differences in fitness levels (low fitness vs. high fitness) were associated with marked differences in the lifetime risks for CVD death at each index age: age 45 years, 13.7% versus 3.4%; age 55 years, 34.2% versus 15.3%; and age 65 years, 35.6% versus 17.1%. These associations were strongest among persons with CVD risk factors.
A single measurement of low fitness in mid-life was associated with higher lifetime risk for CVD death, particularly among persons with a high burden of CVD risk factors.
Twenty years ago, the term 'sarcopenia' has been introduced to describe the ageing related loss of skeletal muscle mass. Since then, sarcopenia has been intensively studied and prevalence values have been reported in fifteen papers covering several continents and races. However, consistency regarding the outcome measures and corresponding cut-off values defining sarcopenia is lacking. Most approaches are based on estimations of muscle mass and proposed cut-off values might be too strict, thus reducing their use in daily practice. From a clinical viewpoint, the assessment of muscle performance (grip strength and endurance) can be proposed as a screening tool showing sufficient sensitivity. The pathophysiology of sarcopenia is multifactorial, and important changes at the tissue level have been identified. Close relationships with inflammatory processes have been demonstrated and there is strong evidence for the involvement of a chronic low-grade inflammatory activity. Sarcopenia is aggravated by a complex interaction of several factors among which aging, disuse, immobilization, disease and malnutrition. A comprehensive geriatric assessment should allow the clinician to estimate the relative contribution of these factors and to elaborate appropriate management. From all interventions studied, intensive resistance training seems the most efficient to counter sarcopenia, even in the very old geriatric patients. Significant ameliorations (up to >50% strength gain) can be expected after six weeks of training at a rhythm of 2-3 sessions per week. From a preventive viewpoint, all elderly patients should be advised to start such an exercise program and continue it as long as possible. To date, most pharmacological interventions to counter sarcopenia include drugs with anabolic effects. Unfortunately, their effect is questionable and no clear guidelines exist for the prescription of these products in the context of sarcopenia.
Physical activity may protect against breast cancer. Few prospective studies have evaluated breast cancer mortality in relation to cardiorespiratory fitness (CRF), an objective marker of physiologic response to physical activity habits.
We examined the association between CRF and risk of death from breast cancer in the Aerobics Center Longitudinal Study. Women (N = 14,811), aged 20 to 83 yr with no prior breast cancer history, received a preventive medical examination at the Cooper Clinic in Dallas, Texas, between 1970 and 2001. Mortality surveillance was completed through December 31, 2003. CRF was quantified as maximal treadmill exercise test duration and was categorized for analysis as low (lowest 20% of exercise duration), moderate (middle 40%), and high (upper 40%). At baseline, all participants were able to complete the exercise test to at least 85% of their age-predicted maximal heart rate.
A total of 68 breast cancer deaths occurred during follow-up (mean = 16 yr). Age-adjusted breast cancer mortality rates per 10,000 woman-years were 4.4, 3.2, and 1.8 for low, moderate, and high CRF groups, respectively (trend P = 0.008). After further controlling for body mass index, smoking, drinking, chronic conditions, abnormal exercise ECG responses, family history of breast cancer, oral contraceptive use, and estrogen use, hazard ratios (95% CI) for breast cancer mortality across incremental CRF categories were 1.00 (referent), 0.67 (0.35-1.26), and 0.45 (0.22-0.95) (trend P = 0.04).
These results indicate that CRF is associated with a reduced risk of dying from breast cancer in women.
Oxygen uptake at the anaerobic threshold (VO(2)AT) is considered as the main determinant for endurance performance in humans. Endurance performance steeply decreases with aging but seems to be kept exceedingly high in elite mountain runners.
To obtain the age- and gender-related upper limits of endurance performance in this sport, we analyzed the results of the World Masters Athletic Championships in Mountain Running 2007. Additionally, to investigate the relationship between the individual VO(2)AT values and running times, laboratory tests were performed in 10 mountain runners.
The World Championships race times of the first 5 finishers of the 5-year age groups did not differ significantly from 35 to 49 years. The corresponding mean (+/- SD) values of the VO(2)AT were 68.0 +/- 1.7 ml/min/kg in males and 58.1 +/- 1.9 ml/min/kg in females. In the following age groups up to 70+ there was a decrease in the VO(2)AT of 29.1% in males and 33.9% in females.
Thus, at the beginning of the 3rd millennium, elite mountain runners demonstrate that VO(2)AT and probably also VO(2max) may be held at top levels in humans up to the age of 45-49 years in both sexes. Despite the following decrease, endurance capacity remains about 3.5-fold higher in elite mountain runners up to 70+ years when compared to their untrained peers.
It is not currently known whether central hemodynamic or peripheral (vascular or metabolic) factors limit maximal oxygen uptake. By measuring the blood flow and oxygen uptake of exercising muscles when only a small fraction of the total muscle mass is engaged in exercise, it has been demonstrated that the skeletal muscle of man could accommodate a blood flow of at least 200 ml/100 g min, and consume 300 ml O2/100 g min at exhaustive exercise. Thus, in whole body exercise the limiting factor is the capacity of the heart to deliver oxygen, not the muscle. It has also been observed that at high perfusion of the muscle the arteriovenous O2 difference is small (14 to 15 vol %), and that the low extraction of oxygen is related to the mean transit time (MTT) of red blood cells passing through the capillaries. It has been concluded that the primary importance of enlargement of the capillary bed with endurance training is not to accommodate flow but to maintain or elongate MTT. It has also been concluded that, in whole body exercise, the capacity of the muscles to receive a flow exceeds by a factor of 2 to 3 the capacity of the heart to supply the flow. Thus, vasoconstrictor tone must also be present in the arteries that "feed" exercising muscles.
We sought to determine a generalized equation for predicting maximal heart rate (HRmax) in healthy adults.
The age-predicted HRmax equation (i.e., 220 - age) is commonly used as a basis for prescribing exercise programs, as a criterion for achieving maximal exertion and as a clinical guide during diagnostic exercise testing. Despite its importance and widespread use, the validity of the HRmax equation has never been established in a sample that included a sufficient number of older adults.
First, a meta-analytic approach was used to collect group mean HRmax values from 351 studies involving 492 groups and 18,712 subjects. Subsequently, the new equation was cross-validated in a well-controlled, laboratory-based study in which HRmax was measured in 514 healthy subjects.
In the meta-analysis, HRmax was strongly related to age (r = -0.90), using the equation of 208 - 0.7 x age. The regression equation obtained in the laboratory-based study (209 - 0.7 x age) was virtually identical to that obtained from the meta-analysis. The regression line was not different between men and women, nor was it influenced by wide variations in habitual physical activity levels.
1) A regression equation to predict HRmax is 208 - 0.7 x age in healthy adults. 2) HRmax is predicted, to a large extent, by age alone and is independent of gender and habitual physical activity status. Our findings suggest that the currently used equation underestimates HRmax in older adults. This would have the effect of underestimating the true level of physical stress imposed during exercise testing and the appropriate intensity of prescribed exercise programs.
Adult skeletal muscle has a remarkable ability to regenerate following myotrauma. Because adult myofibers are terminally differentiated, the regeneration of skeletal muscle is largely dependent on a small population of resident cells termed satellite cells. Although this population of cells was identified 40 years ago, little is known regarding the molecular phenotype or regulation of the satellite cell. The use of cell culture techniques and transgenic animal models has improved our understanding of this unique cell population; however, the capacity and potential of these cells remain ill-defined. This review will highlight the origin and unique markers of the satellite cell population, the regulation by growth factors, and the response to physiological and pathological stimuli. We conclude by highlighting the potential therapeutic uses of satellite cells and identifying future research goals for the study of satellite cell biology.
1. Endurance exercise induces a variety of metabolic and morphological responses/adaptations in skeletal muscle that function to minimize cellular disturbances during subsequent training sessions.
2. Chronic adaptations in skeletal muscle are likely to be the result of the cumulative effect of repeated bouts of exercise, with the initial signalling responses leading to such adaptations occurring after each training session.
3. Recently, activation of the mitogen-activated protein kinase signalling cascade has been proposed as a possible mechanism involved in the regulation of many of the exercise-induced adaptations in skeletal muscle.
4. The protein targets of AMP-activated protein kinase also appear to be involved in both the regulation of acute metabolic responses and chronic adaptations to exercise.
5. Endurance training is associated with an increase in the activities of key enzymes of the mitochondrial electron transport chain and a concomitant increase in mitochondrial protein concentration. These morphological changes, along with increased capillary supply, result in a shift in trained muscle to a greater reliance on fat as a fuel with a concomitant reduction in glycolytic flux and tighter control of acid–base status. Taken collectively, these adaptations result in an enhanced performance capacity.
Cumulative mtDNA damage occurs in aging animals, and mtDNA mutations are reported to accelerate aging in mice. We determined whether aging results in increased DNA oxidative damage and reduced mtDNA abundance and mitochondrial function in skeletal muscle of human subjects. Studies performed in 146 healthy men and women aged 18–89 yr demonstrated that mtDNA and mRNA abundance and mitochondrial ATP production all declined with advancing age. Abundance of mtDNA was positively related to mitochondrial ATP production rate, which in turn, was closely associated with aerobic capacity and glucose tolerance. The content of several mitochondrial proteins was reduced in older muscles, whereas the level of the oxidative DNA lesion, 8-oxo-deoxyguanosine, was increased, supporting the oxidative damage theory of aging. These results demonstrate that age-related muscle mitochondrial dysfunction is related to reduced mtDNA and muscle functional changes that are common in the elderly.
• sarcopenia
• mtDNA
• oxidative damage
• mRNA
• mitochondrial proteins
Increased arterial stiffness and impaired vascular endothelial function are the two most clinically important events that occur with vascular ageing in humans. Together they contribute to age-associated increases in systolic hypertension, left ventricular remodeling and diastolic dysfunction, coronary artery and other atherosclerotic vascular diseases, congestive heart failure, and the attendant cardiac events such as myocardial infarction. However, there is marked individual variability in arterial stiffness and endothelial function with advancing age, which suggests modulation by one or, more likely, several biological and/or lifestyle factors. Consistent with this idea, habitual aerobic exercise appears to attenuate or completely prevent these adverse changes. Other factors including sex hormone status, circulating total and low-density lipoprotein-cholesterol levels, total body and abdominal fatness, and dietary sodium intake also appear to influence arterial stiffening and endothelial dysfunction with ageing. It is now clear that a number of physiological factors and lifestyle behaviors collectively determine how much and, perhaps in some cases, if functionally or clinically significant vascular ageing occurs in adult humans. Of these, the existing evidence indicates that habitual aerobic exercise may be the single most important modulatory influence.
Advancing age is associated with a decline in the strength of the skeletal muscles, including those of respiration. Respiratory muscles can be strengthened with nonrespiratory activities. We therefore hypothesized that regular exercise in the elderly would attenuate this age-related decline in respiratory muscle strength. Twenty-four healthy subjects older than 65 years were recruited (11 males and 13 females). A comprehensive physical activity survey was administered, and subjects were categorized as active (n = 12) or inactive (n = 12). Each subject underwent testing of maximum inspiratory and expiratory pressures (PI(max) and PE(max)). Diaphragmatic thickness (tdi) was measured via two-dimensional B-mode ultrasound. There were no significant differences between the active and inactive groups with respect to age (75 vs. 73 years) or body weight (69.1vs. 69.9 kg). There were more women (9) than men (3) in the inactive group. Diaphragm thickness was greater in the active group (0.31 +/- 0.06 cm vs. 0.25 +/- 0.04 cm; p = 0.011). PE(max) and PI(max) were also greater in the active group (130 +/- 44 cm H(2)O vs. 80 +/- 24 cm H(2)O; p = 0.002; and 99 +/- 32 cm H(2)O vs. 75 +/- 14 cm H(2)O; p = 0.03). There was a positive association between PI(max )and tdi (r = 0.43, p = 0.03). Regular exercise was positively associated with diaphragm muscle thickness in this cohort. As PE(max) was higher in the active group, we postulate that recruitment of the diaphragm and abdominal muscles during nonrespiratory activities may be the source of this training effect.