Article

# Aerobic High-Intensity Intervals Improve V˙O2max More Than Moderate Training

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## Abstract

The present study compared the effects of aerobic endurance training at different intensities and with different methods matched for total work and frequency. Responses in maximal oxygen uptake (VO2max), stroke volume of the heart (SV), blood volume, lactate threshold (LT), and running economy (CR) were examined. Forty healthy, nonsmoking, moderately trained male subjects were randomly assigned to one of four groups:1) long slow distance (70% maximal heart rate; HRmax); 2)lactate threshold (85% HRmax); 3) 15/15 interval running (15 s of running at 90-95% HRmax followed by 15 s of active resting at 70% HRmax); and 4) 4 x 4 min of interval running (4 min of running at 90-95% HRmax followed by 3 min of active resting at 70%HRmax). All four training protocols resulted in similar total oxygen consumption and were performed 3 d.wk for 8 wk. High-intensity aerobic interval training resulted in significantly increased VO2max compared with long slow distance and lactate-threshold training intensities (P<0.01). The percentage increases for the 15/15 and 4 x 4 min groups were 5.5 and 7.2%, respectively, reflecting increases in V O2max from 60.5 to 64.4 mL x kg(-1) x min(-1) and 55.5 to 60.4 mL x kg(-1) x min(-1). SV increased significantly by approximately 10% after interval training (P<0.05). : High-aerobic intensity endurance interval training is significantly more effective than performing the same total work at either lactate threshold or at 70% HRmax, in improving VO2max. The changes in VO2max correspond with changes in SV, indicating a close link between the two.

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... The explanation for this is unclear, but it may be related to increased maximal cardiorespiratory fitness [4,[7][8][9][10][11][12], as maximal cardiorespiratory fitness is generally low in patients with severe obesity [10]. Aerobic exercise with either high-intensity interval training (HIIT), or moderate-intensity continuous training (MICT), is associated with increased maximal cardiorespiratory fitness, both in persons with normal-weight and obesity [13][14][15][16]. However, previous studies have reported larger improvements in maximal cardiorespiratory fitness after HIIT than after MICT [13,17,18]. ...
... Aerobic exercise with either high-intensity interval training (HIIT), or moderate-intensity continuous training (MICT), is associated with increased maximal cardiorespiratory fitness, both in persons with normal-weight and obesity [13][14][15][16]. However, previous studies have reported larger improvements in maximal cardiorespiratory fitness after HIIT than after MICT [13,17,18]. Further, 16 weeks of high-intensity or moderate-intensity exercise that leads to small weight losses was shown to improve general health and physical functioning as measured by the generic HRQOL questionnaire Short Form Health Survey (SF-36) in healthy inactive individuals with a wide range of body mass index (BMI) (33.3-64.8 ...
... Third, as is usual for this kind of exercise study, the dropout rate was relatively high. [13,18,[40][41][42], which might have biased the results. Fourth, the proportion of patients who completed the exercise program was considerably lower in the HIIT/MICT group than MICT, which might have biased the results. ...
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Background Aerobic exercise is an important part of obesity treatment and may improve health-related quality of life (HRQOL). The objective of this study was to compare the effect of two different exercise programs on health-related quality of life in patients with severe obesity. Methods This was a single-center, open-label, randomized, parallel-group study comparing the effects of a 24-week moderate-intensity continuous training (MICT) program and a combined high-intensity interval training program with MICT (HIIT/MICT). The primary objective (specified secondary outcome) was to assess HRQOL by using the general health dimension of the Short Form Health Survey (SF-36). The secondary objectives were to assess other dimensional SF-36 scores, the impact of weight on the physical and psychosocial aspects of quality of life (IWQOL-Lite), and the burden of obesity-specific weight symptoms (WRSM). Results 73 patients were enrolled and reported patient reported outcome measures, with 71 patients (55% females) allocated to either MICT (n = 34) or HIIT/MICT (n = 37). In the intention-to-treat analysis, general health scores increased between baseline and 24-week follow-up in both the HIIT/MICT group and the MICT group, with a mean change of 13 (95% CI 6–21) points and 11 (95% CI 5–17) points, respectively, with no difference between the groups. The effect sizes of these changes were moderate. The vitality and social functioning scores of SF-36, and the physical function and self-esteem scores of IWQOL-Lite increased moderately in both groups, with no difference between groups. The tiredness, back pain, and physical stamina scores based on WRSM showed moderate to strong changes in both the groups. Conclusions Patients who had completed a combined HIIT/MICT program did not experience larger improvements in general health compared with those completing a clean 24-week MICT program. Exercise may confer general health benefits independent of intensity. Trials registration Regional Committees for Medical and Health Research Ethics south east, Norway, October 23, 2013 (identifier: 2013/1849) and ClinicalTrials.gov December 8, 2014 (identifier: NCT02311738).
... Only modified to running velocity, the same equation showed similar results in a large cohort of recreational to elite runners in Støa et al. (2020). In addition, in previous training interventions, improvements in LT v or power at LT are often displayed together with improvements of either VO 2max or C, or both (e.g., Helgerud et al., 2001Helgerud et al., , 2007Enoksen et al., 2011;Stöggl and Sperlich, 2014;Rønnestad et al., 2016). Støren et al. (2014) suggest that by measuring MAS exclusively, a subsequent LT v could be calculated, given no change in LT. ...
... The individual LT value was calculated by the individual warm-up lactate value +2.3 mmol·L −1 . This protocol is presented and evaluated in Helgerud et al. (1990) and Medbø et al. (2000) and previously used in several studies (Helgerud et al., 2007;Støren et al., 2013Støren et al., , 2014Sunde et al., 2019;Johansen et al., 2020;Støa et al., 2020). The mean VO 2 during the last minute of every work period was used to calculate C DP and LT. ...
... This assumption is further strengthened by the significant correlation between ∆MAS and ∆LT v in the present study. Previous training interventions also support the strong determinant impact of MAS on LT v , since improvements in LT v are frequently observed together with increased MAS (Helgerud et al., 2001(Helgerud et al., , 2007Enoksen et al., 2011). Støren et al. (2014) suggested that a subsequent LT v could be calculated only by measuring MAS at subsequent testing sessions, given no change in LT. ...
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PurposeTo investigate the relationships between maximal aerobic speed (MAS), lactate threshold in per cent of peak oxygen uptake (LT) and velocity at LT (LTv) in cross-country skiers. Secondly, we aimed to explore the fit of an equation previously used in cyclists and runners in a cohort of well-trained, competitive cross-country skiers for calculation of LTv. Thirdly, we aimed to investigate if a new LTv could still be calculated after a period of regular training only by providing a new MAS.Methods Ninety-five competitive cross-country skiers (65 males and 30 females) were tested for maximal oxygen uptake (VO2max), peak oxygen uptake in double poling (DP-VO2peak), oxygen cost of double poling (CDP), LT, and LTv. Thirty-five skiers volunteered to be tested 3 months later to evaluate potential changes in LT and LTv.ResultsVelocity at LT was mainly determined by MAS (r = 0.88, p < 0.01). LT did not show a significant impact on LTv. The product of MAS·LT precisely predicted LTv at baseline (r = 0.99, SEE = 2.4%), and by only measuring MAS, a new LTv could be accurately calculated (r = 0.92, SEE = 6.8%) 3 months later in a sub-set of the initial 95 skiers (n = 35).Conclusion The results suggest that LT has minor impact on LTv in DP tested in a laboratory. LTv seemed to be predominantly determined by MAS, and we suggest to put more focus on MAS and less on LT and LTv in regular testing to evaluate aerobic performance capacity in DP.
... Even though the total training volume of HIIT sessions is generally considerably lower than that of 'High-Volume (low-intensity) Training' without recovery breaks (<65% of HR max, blood lactate levels < 2 mmol/L, training duration > 30 min), comparative studies often proved similar or even better effects on endurance capacity and maximal oxygen uptake capacity when HIIT sessions were used. These studies were conducted with moderately trained children, teenagers and adults [23][24][25][26][27]. Additionally, highly trained endurance athletes, who predominantly use 'High-Volume low-intensity Training', seem to profit when at least regularly implementing HIIT protocols in their training schedule [24]. ...
... The selection and choice of specific training parameters (duration and number of intervals) when using HIIT protocols seems arbitrary, and there is no gold standard related to training parameters. Several studies found optimal effects of intervals lasting between 2 and 5 min [24,26,29]. Other authors recommend shorter intervals between 15 and 30 s [30,31]. ...
... Peer-reviewed published literature on ultrashort training loads of 5-70 s is currently lacking, and only a few older studies addressed the topic. Helgerud et al. [26] found similar training effects when using 15 s intervals compared to 4 min intervals. ...
Article
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High-Intensity Interval Training (HIIT) promises high training effects on aerobic fitness in children, adolescents and adults in a relatively short time. It is therefore well-established in professional training settings. HIIT methods could also be suited to Physical Education (P.E.) lessons and contribute to students’ health and fitness. Since HIIT sessions need little time and equipment, they can be efficiently implemented in P.E. However, there are few studies which have examined non-running-based HIIT programs in the school sport setting. We therefore conducted an intervention study including 121 students aged 11–15 attending a secondary school in Baden Württemberg, Germany. The effects of three different forms of HIIT training varying in duration and content (4 × 4 HIIT, 12 × 1 HIIT, CIRCUIT) were analyzed. The training was conducted twice a week over 6 weeks (10–12 sessions). Strength and endurance performances were determined in pre- and posttests prior to and after the intervention. Results verified that all three HIIT programs led to significant improvements in aerobic fitness (p < 0.001; part ŋ2 = 0.549) with no significant interaction between time x group. In contrast to the running-based HIIT sessions, CIRCUIT training also led to significant improvements in all of the measured strength parameters. Retrospectively, students were asked to assess their perception of the training intervention. The HIIT sessions were well-suited to students who considered themselves as “athletic”. Less athletic students found it difficult to reach the necessary intensity levels. The evaluation showed that endurance training conducted in P.E. lessons needs a variety of different contents in order to sufficiently motivate students. Students perceiving themselves as “unathletic” may need additional support to reach the required intensities of HIIT. Circuit training sessions using whole-body drills can be efficiently implemented in the P.E. setting and contribute to students’ health and fitness.
... Die Gründe für die hohe Beliebtheit des HIIT sind dabei sehr vielschichtig. Hochintensive Intervalltrainingsprogramme werden zunehmend im Leistungs-und Breitensport gezielt zur Verbesserung der Ausdauerleistungsfähigkeit, sowie zur Verbesserung der maximalen Sauerstoffaufnahme (VO2max) eingesetzt (Helgerud et al., 2007). Vor allem in den Ausdauersportarten bedarf es ab einem fortgeschrittenen Leistungsniveau einer Erhöhung der Intensitäten und Trainingsreize innerhalb des Trainingsprozesses, um eine kontinuierliche Steigerung der Ausdauerleistungsfähigkeit erzielen zu können. ...
... Häufig findet allerdings bei gut ausdauertrainierten Sportlern das Belastungs-Pausenverhältnis von 2:1 oder 1:1 in der Praxis seine Anwendung (Rozenek et al., 2007). Für untrainierte Personen lässt sich häufig das Trainingsprotokoll von vier bis sechs Intervallen mit einer Belastungslänge von 30 Sekunden sowie einer aktiven Pausenzeit von drei bis vier Minuten in der Literatur finden (Gibala & Little, 2010 (Helgerud et al., 2007). Die Zielstellung eines HIIT ist ein wiederholtes Provozieren von starken Stresssituationen für die involvierten physiologischen Systeme, die von höherer Intensität sind als die durchschnittliche Intensität im Zielwettkampf (Laursen & Jenkins, 2002). ...
... Weiterhin konnten Costigan et al. (2015) zeigen, dass ein hochintensives Intervalltraining eine günstigere Beeinflussung des BMI sowie des Körperfettanteils nach sich zieht. Zusätzlich zeigt ein HIIT stärkere Effekte auf die Herz-Kreislauf-Gesundheit als ein herkömmliches Ausdauertraining (Helgerud et al., 2007). Basierend auf diesen Erkenntnissen findet diese Trainingsmethode auch immer häufiger Anwendung im Rehabilitations-und Präventionssport (Gibala, 2007). ...
Thesis
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High-intensity interval training, characterized by repetitive short to long bouts of high-intensity exercise separated by recovery periods, represents a time-efficient training methodology for improving athlete performance. Previous research indicates that physiological and anatomical differences in men and women may result in divergences in training response. Furthermore, the state of research suggests that changes in skeletal muscle and different functional systems over the course of age may induce different responses to an exercise stimulus. In this regard, the results show that there is a sexual dimorphism in load and recovery during interval exercise. Furthermore, it was found that good trainability is possible in old age, which in turn may counteract age-related changes and their influence on load and recovery behavior.
... Physical inactivity is one of the leading health problems in the world. Exercise is important for rehabilitation, to enhance health, and for health maintenance, in addition to its role in conditioning for competitive sports [1][2][3]. Robust evidence shows that low levels of cardiorespiratory fitness (CRF) are associated with a high risk of cardiovascular disease and all-cause mortality. CRF, typically assessed by directly measuring maximal oxygen consumption (VO 2max ), is a potentially stronger predictor of mortality than established risk factors such as smoking [4]. ...
... This continued until the participant reached exhaustion after about 5 minutes to 8 minutes. To ensure that VO 2max was reached, the participants were encouraged to continue as long as possible so that a leveling off of VO 2 occurred [1]. A plateau was displayed by all participants at the end of the test, confirming VO 2max . ...
... The HIIT protocol used in Myworkout GO was performed individually on the treadmill, walking or running, and consisted of a 6-minute warm-up at "talking speed." Then, the participants underwent a 4x4-minute interval training (breathing heavy but with no obvious feeling of lactic acid accumulation), interrupted by 3 minutes of active rest periods at "talking speed" between each interval [1]. The 2 HIIT sessions were performed in a supervised setting by an exercise physiologist; however, the exercise itself was guided by the app, with the following instructions: ...
Article
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Background Physical inactivity remains the largest risk factor for the development of cardiovascular disease worldwide. Wearable devices have become a popular method of measuring activity-based outcomes and facilitating behavior change to increase cardiorespiratory fitness (CRF) or maximal oxygen consumption (VO2max) and reduce weight. However, it is critical to determine their accuracy in measuring these variables. Objective This study aimed to determine the accuracy of using a smartphone and the application Myworkout GO for submaximal prediction of VO2max. Methods Participants included 162 healthy volunteers: 58 women and 104 men (17-73 years old). The study consisted of 3 experimental tests randomized to 3 separate days. One-day VO2max was assessed with Metamax II, with the participant walking or running on the treadmill. On the 2 other days, the application Myworkout GO used standardized high aerobic intensity interval training (HIIT) on the treadmill to predict VO2max. Results There were no significant differences between directly measured VO2max (mean 49, SD 14 mL/kg/min) compared with the VO2max predicted by Myworkout GO (mean 50, SD 14 mL/kg/min). The direct and predicted VO2max values were highly correlated, with an R2 of 0.97 (P<.001) and standard error of the estimate (SEE) of 2.2 mL/kg/min, with no sex differences. Conclusions Myworkout GO accurately calculated VO2max, with an SEE of 4.5% in the total group. The submaximal HIIT session (4 x 4 minutes) incorporated in the application was tolerated well by the participants. We present health care providers and their patients with a more accurate and practical version of health risk estimation. This might increase physical activity and improve exercise habits in the general population.
... Physical exercise is one method, which has been documented to improve components of EF, (Faulkner et al., 2017;Lambrick, Stoner, Grigg, & Faulkner, 2016), specifically inhibitory control, reaction time and set shifting ability in healthy young adults (Coles & Tomporowski, 2008). High intensity intermittent exercise (HIIE) has gained interest recently, which includes a number of bouts of exercising at high intensities (90-95% of HR max) interspersed by intervals of exercise at lower intensities (70% of HR max) (Helgerud et al., 2007). HIIE has gained popularity among young adults as it has been shown to be an effective way to raise metabolism hence associated with better weight control (Boutcher, 2011;Heydari, Freund, & Boutcher, 2012). ...
... A duration of 25 minutes of HIIE with intermittent 4 Â 4 bouts of high intensity (at 90-95% of HR max) and 3 minutes recovery periods in between (at 70% of HR max) (Helgerud et al., 2007) is achievable by sedentary individuals as a beginning protocol to improve fitness and is frequently adopted. This duration of exercise also fulfills the guidelines of physical activity recommendation for healthy adults, provided by ACSM. ...
... HIIE protocol was of 4 bouts of 4 minutes (4 Ã 4) at 90-95% HRmax with 3 minutes of active recovery at 70% HRmax (Helgerud et al., 2007) on a cycle ergometer (Lode Corival BV, Groningen-The Netherlands) . Heart rate was monitored using Polar heart rate Monitor (Polar Vantage V Pro Multisports Watch). ...
Article
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We investigated prefrontal cortex (PFC) hemodynamic response, through functional near infrared spectroscopy (fNIRS) during executive function (EF) processing in response to acute high intensity intermittent exercise (HIIE) in young adults. We also assessed the associated sex differences in the cognitive scores and related PFC hemodynamic functions in response to HIIE. 49 young healthy adult participants (32 women, 17 men) were randomly assigned to either control or HIIE intervention groups. HIIE group participants performed 4 × 4 minutes of HIIE on cycle ergometer with 3 minutes of active recovery between the bouts; control group relaxed for the time equivalent to intervention. fNIRS data was collected during the performance of the EF tests including Color Word Stroop Test (CWST) and Trail Making Test (TMT) in pre and post sessions in both the groups. Results indicated a significant change in the hemodynamic response in the form of increased oxygenated and decreased deoxygenated hemoglobin in the PFC areas specific to the EF tasks, with improved CWST and TMT scores in response to HIIE intervention. PFC activation was different in men and women in response to HIIE, however similar scores of task performance were observed in men and women during the performance of executive functions in response to HIIE. The study concludes that an acute HIIE session improves executive function which is associated with an increase activation of PFC. Sex differences exist in the activation of PFC in response to HIIE during EF processing. Our study adds to the current evidence regarding exercise and cognition.
... In addition to the pre-season soccer training, a continuous running protocol was applied for 45 minutes at 70% of the maximum heart rate (maxHR) of the players immediately after the end of the unit training (24). In long-term jogs applied as additional training, the participants' HR was kept at the desired levels by means of polar watches worn by the participants. ...
... In addition to the pre-season period soccer training in the high-intensity interval training (HIIT) group, a running protocol was applied for 90-95% of the maximum heart rate (maxHR) of the athletes for 15 seconds immediately after the end of the unit training. In 70% of maxHR, a high-intensity interval running protocol was applied with a rest period of 15 seconds, with a total of 8 repetitions, 3 sets and 3 minutes of rest between sets (24). In high-intensity interval runs applied as additional training, the participants' HR was kept at the desired levels by means of polar watches worn by the participants. ...
... These results show us that the groups were formed homogeneously. There is a common view that there is an increase in VO2max values with high-intensity aerobic training (16,20,24). While Mcmillan et al (30) revealed that the increase in VO2max value in each training unit was 0.56% with high-intensity training, Helgerud et al (23) found this rate to be 0.67% in their study. ...
Article
The aim of this study is to examine the effects of different training methods on aerobic performance and respiratory parameters in young soccer players. For this purpose, fourty healthy young male soccer players participated in the study. The mean age of the participants was 16.72± 1.09 years, their average height was 172.45± 5.56 cm and their body weight average was 62.79± 8.91 kg. The study protocol was approved by the Selcuk University Faculty of Sport Sciences Ethics Committee. Different training methods applied in the study were applied in addition to routine training programs 3 times a week for 8 weeks. Fourty soccer players who participated in the study were divided into 5 groups as the control group (CG), small sided games (SSG), transition in SSG (TSSG), high intensity interval training (HIIT) and low intensity continuous training (LICT) groups. Three measurements were made for aerobic performance (VO2max), lactate levels and rating of perceived exertion (RPE). And also, two measurements were applied for respiratory parameters. As a result, significantly increased the VO2max levels of the other groups except the SSG group. LICT significantly decreased lactate levels. RPE were found to be significantly higher in the HIIT in all three measures. It provided significant increases in force vital capacity (FVC) and the forced expiratory volume in 1 second (FEV1) levels of LICT and HIIT groups. There was a significant decrease in the FEV1/FVC levels of the LICT and the peak expiratory flow (PEF) levels of the HIIT. As a result, different trainings applied for eight weeks significantly improved aerobic performance and decreased lactate levels. It resulted in different changes in RPE levels and respiratory parameters. Özet Bu çalışmanın amacı genç futbolcularda farklı antrenman yöntemlerinin aerobik performans ve solunum parametreleri üzerine etkilerini incelemektir. Bu amaçla, çalışmaya sağlıklı 40 genç erkek futbolcu katılmıştır. Katılımcıların yaş ortalamaları 16.72± 1.09 yıl, boy ortalamaları 172.45± 5.56 cm ve vücut ağırlığı ortalamaları 62.79± 8.91 kg olarak tespit edilmiştir. Çalışma protokolü Selçuk Üniversitesi Spor Bilimleri Fakültesi girişimsel olmayan etik kurulu tarafından onaylanmıştır. Çalışmada uygulanan farklı antrenman yöntemleri, 8 hafta boyunca haftada 3 kez rutin antrenman programlarına ek olarak uygulanmıştır. Çalışmaya katılan 40 futbolcu, kontrol grubu, sınırlı alan oyunları (SAO), sınırlandırılmış alanlarda geçiş oyunu (SAGO), yüksek şiddetli interval antrenman (YŞİA) ve
... Another important factor for aerobic endurance performance [51], along with VȮ 2max , is work efficiency, the ratio between work output and oxygen uptake [52,53]. Physical work conducted less efficiently implies that human locomotion requires more energy and oxygen consumption, resulting in impaired aerobic endurance and poorer physical function during activities of daily living. ...
... Similar to what has been observed in healthy individuals [53] and other patient populations [83,84], endurance training with high aerobic intensity seems to yield greater increases in V O 2peak compared to endurance training with moderate aerobic intensity. In line with this notion, high-intensity aerobic interval training (4-min intervals at ~ 90% of peak heart rate with intermittent active rest periods) was demonstrated to increase pulmonary measured treadmill V O 2peak by 3.1-4.2 ...
... Used with permission from Nygård et al. [54]. other cohorts, such as patients with substance use disorder [86], coronary artery disease [83], and young adults [53]. Although one study failed to document aerobic interval training-induced improvement in V O 2peak with intention-to-treat analyses in people with schizophrenia [87], explorative ad hoc analyses revealed a V O 2peak difference of 4.7 ml kg −1 min −1 after training between subjects instructed by personnel with (2.4 ml kg −1 min −1 increase) or without (2.2 ml kg −1 min −1 decrease) competence in supervising the sessions. ...
Article
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Background Individuals with severe mental disorders (SMDs; schizophrenia spectrum disorders, bipolar disorder, and major depressive disorder) are not only suffering from their mental conditions; they also have an attenuated physical health, augmenting their overall critical condition. Objectives We review and critically appraise the evidence based on (1) key physiological factors relating to aerobic endurance and skeletal muscle strength; (2) implications for physical function and health; and (3) effects of training interventions with different intensities evaluated in individuals with SMDs. Findings Reductions in aerobic endurance factors, peak oxygen uptake (VO2peak) and walking work efficiency, are paralleled by reductions in maximal skeletal muscle strength and power. In turn, the poor aerobic endurance and muscle strength lead to impaired physical function, increased risk of lifestyle-related diseases, and ultimately early death. Exercise has the potential to counteract the attenuated physical health in people with SMDs. While aerobic endurance training is shown to increase VO2peak due to plasticity of the oxygen transport system, strength training is documented to improve maximal muscle strength, power, and walking work efficiency as a result of adaptations in neuromuscular force developing factors. Conclusions In conclusion, improvements in these key determinants for physical health appear to be achievable in people with SMDs despite many being challenged by motivational difficulties with attending regular exercise and have beneficial implications for physical function during activities of daily living, lifestyle-related diseases, and early death.
... Satisfactorily, "exercise control" and "direct supervision" criteria of reporting quality achieved the highest assessments. Among studies that did not equalize protocols, twenty-one compared HIIT with typical MICT programs (Figure 3) that had been designated by previous studies to be equal based on energy expenditure or production [24]. Therefore, although protocol equalization was not reported in the methods section of these studies, it had possibly been achieved anyway, thereby increasing the proportion of protocols actually equalized. ...
... The primary methods used for protocol equalization were energy-based. Most studies measured exercise-induced energy expenditure through oxygen consumption, while some others measured external work based on power output and exercise duration [12,24,25]. Energy expenditure methods typically incorporated both exercise and recovery periods, while methods based on external work only considered exercise bouts. ...
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Based on comparisons to moderate continuous exercise (MICT), high-intensity interval training (HIIT) is becoming a worldwide trend in physical exercise. This raises methodological questions related to equalization of exercise dose when comparing protocols. The present scoping review aims to identify in the literature the evidence for protocol equalization and the soundness of methods used for it. PubMed and Scopus databases were searched for original investigations comparing the effects of HIIT to MICT. A total of 2041 articles were identified, and 169 were included. Of these, 98 articles equalized protocols by utilizing energy-based methods or exercise volume (58 and 31 articles, respectively). No clear consensus for protocol equalization appears to have evolved over recent years. Prominent equalization methods consider the exercise dose (i.e., energy expenditure/production or total volume) in absolute values without considering the nonlinear nature of its relationship with duration. Exercises resulting from these methods induced maximal exertion in HIIT but low exertion in MICT. A key question is, therefore, whether exercise doses are best considered in absolute terms or relative to individual exercise maximums. If protocol equalization is accepted as an essential methodological prerequisite, it is hypothesized that comparison of program effects would be more accurate if exercise was quantified relative to intensity-related maximums.
... In the last few years, a large number of studies have been published which have shown positive effects of HIIT on aerobic power in children and adults. Positive effects are shown especially in maximum oxygen uptake (VO 2max ), power at the ventilator thresholds (VT1 and VT2) and power at the lactate threshold (Engel, Ackermann, Chtourou & Sperlich, 2018;Esfarjani & Laursen, 2007;Helgerud et al., 2007;Laursen, Blanchard & Jenkins, 2002). In artistic gymnastics, HIIT as a training method for aerobic power has become a greater focus of attention (Salagas, Donti, Katsikas & Bogdanis, 2020). ...
... The lack of improvement in VO 2peak after HIIT in this study contradicts the results of Schoenmakers et al. (2016) who demonstrated an increase in VO 2peak after HIIT. An increase in VO 2peak after HIIT has also been shown in studies on the cycle ergometer or treadmill (Edge et al., 2006;Helgerud et al., 2007). One reason for the lack of increase in VO 2peak can be seen in the difference in VO 2 uptake kinetics between upper and lower body exercise. ...
Article
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Problem Statement. While there is an agreement on specific endurance training for typical endurance sports such as running, swimming and cycling, there is a need for discussion for sports with short-term high-intensity exercise like artistic gymnastics. Purpose. The aim of this study was to investigate the effects of gymnastics-specific high intensity interval training on endurance performance on the pommel horse and the arm ergometer. Materials and methods. Endurance performance on the pommel horse was determined by the maximum number of circles, endurance performance on the arm ergometer by peak power and power at the ventilatory thresholds 1 and 2. In addition, the effect on oxygen uptake, peak blood lactate concentration and peak heart rate on the pommel horse and arm ergometer should be investigated. Eleven gymnasts (age: 15.27 ± 2.49 years; weight: 55.5 ± 12.8 kg; height: 163.5 ± 12.2 cm) from a local gymnastics club performed high intensity interval training 2 times per week for 4 weeks. The high intensity interval training consisted of ten 40 s intervals (2 x 5 upper body exercises with 90% of the maximum heart rate) and a rest period of 60 s between each interval. Results. The maximum number of circles (56.0 to 66.5), peak power (160.5 to 194.5 W), power at the ventilatory thresholds 1 (79.0 to 104.5 W) and power at the ventilatory thresholds 2 (132.5 to 156.0 W) increased significantly from pre-to post-test. Peak oxygen uptake shows a significant decrease on the arm ergometer (47.2 to 43.1 ml/min/kg), but no significant change on the pommel horse (42.9 to 43.2 ml/min/kg). Peak blood lactate concentration and peak heart rate show no change from pre to post test on the pommel horse and arm ergometer. Conclusions. The results of the study show that gymnastics-specific high intensity interval training is a time-efficient training method for improving upper body and pommel horse-specific endurance performance.
... BMC Sports Science, Medicine and Rehabilitation (2022) 14:84 Background Athletes use high-intensity interval training (HIIT) as a complementary training method to continuous endurance training [1]. HIIT sessions are usually less time-consuming but still effective to improve the aerobic fitness compared with high volume low-intensity sessions [2][3][4][5][6]. ...
... LIT serves as a potent stimulus to enhance fat oxidation and glucose utilization, which are essential for aerobic energy provision during prolonged endurance training [61][62][63][64]. In contrast, HIIT may lead to cardiopulmonary improvements, such as increased stroke and blood volume [2,65]. In addition, metabolic alterations [66] such as increased mitochondrial biogenesis and oxidative capacity are possible [67][68][69]. ...
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Background Performing multiple high-intensity interval training (HIIT) sessions in a compressed period of time (approximately 7–14 days) is called a HIIT shock microcycle (SM) and promises a rapid increase in endurance performance. However, the efficacy of HIIT-SM, as well as knowledge about optimal training volumes during a SM in the endurance-trained population have not been adequately investigated. This study aims to examine the effects of two different types of HIIT-SM (with or without additional low-intensity training (LIT)) compared to a control group (CG) on key endurance performance variables. Moreover, participants are closely monitored for stress, fatigue, recovery, and sleep before, during and after the intervention using innovative biomarkers, questionnaires, and wearable devices. Methods This is a study protocol of a randomized controlled trial that includes the results of a pilot participant. Thirty-six endurance trained athletes will be recruited and randomly assigned to either a HIIT-SM (HSM) group, HIIT-SM with additional LIT (HSM + LIT) group or a CG. All participants will be monitored before (9 days), during (7 days), and after (14 days) a 7-day intervention, for a total of 30 days. Participants in both intervention groups will complete 10 HIIT sessions over 7 consecutive days, with an additional 30 min of LIT in the HSM + LIT group. HIIT sessions consist of aerobic HIIT, i.e., 5 × 4 min at 90–95% of maximal heart rate interspersed by recovery periods of 2.5 min. To determine the effects of the intervention, physiological exercise testing, and a 5 km time trial will be conducted before and after the intervention. Results The feasibility study indicates good adherence and performance improvement of the pilot participant. Load monitoring tools, i.e., biomarkers and questionnaires showed increased values during the intervention period, indicating sensitive variables. Conclusion This study will be the first to examine the effects of different total training volumes of HIIT-SM, especially the combination of LIT and HIIT in the HSM + LIT group. In addition, different assessments to monitor the athletes' load during such an exhaustive training period will allow the identification of load monitoring tools such as innovative biomarkers, questionnaires, and wearable technology. Trial Registration : clinicaltrials.gov, NCT05067426. Registered 05 October 2021—Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT05067426 . Protocol Version Issue date: 1 Dec 2021. Original protocol. Authors: TLS, NH.
... HIIE protocol was of 4 bouts of 4 minutes (4*4) at 90-95% HRmax with 3 min active recovery at 70% HRmax in accordance with Helgerud et al., 2007. HR max (beats/min) was calculated by the formula: HRmax = 206.9 ...
... We aimed to determine sex-specific effect of high intensity intermittent exercise on the concentration of neurotrophic factors in young adults. For this purpose, 4 sessions of high intensity intermittent exercise for 4 minutes each at intensities between 90-95% of HR max, with 3 minutes of active rest in between the sessions were used (Helgerud et al., 2007) as an intervention of the study. Blood for the assessment of neurotrophic factors and other hormones was extracted before and after the intervention. ...
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The neurophysiological response to exercise on cognition is modulated through chemical pathways which involve several neurotrophic factors and the sex of the individual determines this effect. We examined sex differences in the concentration of neural growth factors (NGF); brain derived neurotrophic factor (BDNF), vascular endothelial growth factor (VEGF) and insulin like growth factor-I (IGF- I) in response to acute high intensity intermittent exercise (HIIE). We also evaluated the relationship of NGF with gonadal hormones before and after the HIIE session. Forty healthy young adults (22 males and 18 females) performed HIIE (4 bouts of 4 minutes at 90–95% HR max with 3min active recovery at 70% HRmax). Venous blood was drawn before and immediately after the exercise session and was analyzed for the concentration of serum BDNF, VEGF, IGF-I, cortisol, estradiol, luteinizing hormone (LH), follicle stimulating hormone (FSH) and testosterone, using ELISA method. A significant sex difference (p<0.05) was observed for BDNF concentration in response to HIIE and a significant increase was found in males but not in females. A significant (p<0.005) positive correlation of BDNF with FSH and LH and a significant (p<0.05) negative correlation of BDNF and VEGF with testosterone were found. Other NGFs (VEGF and IGF-I) did not show sex differences in response to HIIE. In conclusion, a single session of HIIE increases the serum concentration of BDNF in males and IGF-I in females and the response of NGF is different in males and females.
... Due to its effectiveness, training under high intensities is common among runners. One popular example is high-intensity interval training (HIIT) [8]. During this type of training, runners perform shorter intervals at a high intensity rather than prolonged jogging at a low intensity. ...
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Even though running enjoys growing popularity, the effects of fatigue on the running kinematics of novices have rarely been studied. This is surprising, given the risk of running-related injuries when detrimental movement patterns are adopted. Therefore, the goal of the present study was to characterize the effects of fatigue induced by a high-intensity running protocol on spatiotemporal and stiffness parameters as well as on joint kinematics and center of mass (CoM) motion in novice runners. 14 participants performed a standardized treadmill familiarization and ran at 13 km/h until voluntary exhaustion. Kinematics were captured using a 3D motion capture system. Spatiotemporal and stiffness parameters as well as the range of motion (RoM) of the joints and CoM were compared by use of paired t-tests. Time series of the joint angles and CoM motion were analyzed by the statistical parametric mapping method. The results revealed that novice runners did not change spatiotemporal or stiffness parameters, but showed adaptations in joint kinematics, e.g. decreased dorsiflexion and increased pronation in the ankle joint during the swing phase. The findings of this study underline the importance of strengthening the ankle joint to prevent excessive pronation and increase its stability in novice runners.
... The historical view is that, compared to a high frequency of LIT bouts, high-intensity training (HIT) stimulates central adaptations to a larger degree (e.g., increased stroke volume of the heart) [127][128][129]. However, in welltrained athletes that are performing a high total volume of training, further increases in V O 2 max are not consistently observed after periods of increased HIT [130][131][132]. ...
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In this review we integrate the scientific literature and results-proven practice and outline a novel framework for understanding the training and development of elite long-distance performance. Herein, we describe how fundamental training characteristics and well-known training principles are applied. World-leading track runners (i.e., 5000 and 10,000 m) and marathon specialists participate in 9 ± 3 and 6 ± 2 (mean ± SD) annual competitions, respectively. The weekly running distance in the mid-preparation period is in the range 160–220 km for marathoners and 130–190 km for track runners. These differences are mainly explained by more running kilometers on each session for marathon runners. Both groups perform 11–14 sessions per week, and ≥ 80% of the total running volume is performed at low intensity throughout the training year. The training intensity distribution vary across mesocycles and differ between marathon and track runners, but common for both groups is that volume of race-pace running increases as the main competition approaches. The tapering process starts 7–10 days prior to the main competition. While the African runners live and train at high altitude (2000–2500 m above sea level) most of the year, most lowland athletes apply relatively long altitude camps during the preparation period. Overall, this review offers unique insights into the training characteristics of world-class distance runners by integrating scientific literature and results-proven practice, providing a point of departure for future studies related to the training and development in the Olympic long-distance events.
... The continue form in aerobic exercise is not suited to cancer patients who are characterized by early fatigability and lack motivation.The training methodology recommended the use of intermittent exercise to avoid the constraint of motivation and fatigue. Beyond the fatigability and motivational aspects related to aerobic continuous exercise, intermittent training has been shown efficiency greater benefits compared to continuous one(Helgerud and al. 2007). ...
Thesis
L'objectif de ce travail était d'étudier les effets combinés d'un entrainement aérobie intermittent supervisé, d'un entrainement de renforcement musculaire et d'électrostimulation et d'un programme de marche continu à domicile, sur l'aptitude cardiorespiratoire, sur la fonction musculaire et la qualité de vie des patientes atteintes d'un cancer du sein au cours de traitement par chimiothérapie adjuvante. Les mesures ont été réalisées avant et après 6 semaines d'entrainement sur un groupe entrainé (n=20), et à 6 semaines d'intervalle sans modification de l'activité physique sur un groupe témoin (n= 12). Par comparaison avec les témoins, la première étude a montré les effets positifs de notre protocole d'entrainement sur l'aptitude aérobie et les besoins métaboliques de nos patientes entrainées. De même, la deuxième étude a révélé les importantes augmentations de la FMVi, du TE lors d'un test isométrique, et de la désoxygénation musculaire ΔHHb, suggérant une amélioration de l'utilisation de l'oxygène au niveau musculaire dans le groupe entrainé après six semaines d'entrainement. Par ailleurs, les résultats de la troisième étude ont confirmé les effets sur la fonction musculaire, en observant une amélioration de l'activité myoélectrique du vaste latéral, caractérisée par la diminution du RMS et l'augmentation du MPF lors de la phase du maintien à 50% de la FMVi, dans le groupe entrainé après les six semaines d'entrainement combiné aérobie et de renforcement musculaire. Enfin, dans la quatrième étude, nous avons observé une amélioration significative de la qualité de vie du groupe entrainé. Cette amélioration est caractérisée d'une part, par une augmentation de la qualité de vie globale et des scores aux échelles fonctionnelles, d'autre part, d'une réduction des scores des échelles de symptômes chez les cancéreuses traitées par chimiothérapie adjuvante
... High-intensity interval exercise (HIIE) is traditionally characterized by brief periods of vigorous exercise performed at "near maximal" efforts and intensities which elicit ≥85% of maximum heart rate (%HRmax) and/or ≥ 80% of maximum oxygen consumption (%VO 2 max), separated by periods of active or passive recovery (Helgerud et al., 2007;MacInnis and Gibala, 2017). According to the American College of Sports Medicine (ACSM), vigorous aerobic exercise can also be classified as 64-90% VO 2 max, 77-95%HRmax, and a rating of perceived exertion of somewhat hard to very hard (RPE 14-17; Garber et al., 2011;American College of Sports Medicine, 2018). ...
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Objective The purpose of this study was to compare the acute physiological, perceptual, and enjoyment responses between bodyweight high-intensity interval exercise (BW-HIIE) and treadmill running high-intensity interval exercise HIIE (RUN-HIIE). Methods Twelve adults [age: 29.5 ± 5.3 years; weight: 70.9 ± 15.0 kg; height: 167.9 ± 8.9 cm; peak oxygen consumption (VO 2 peak): 48.7 ± 6.5 ml min ⁻¹ ·kg ⁻¹ ] performed both RUN-HIIE and BW-HIIE. RUN-HIIE consisted of two sets of 5, 60-s (s) run intervals at 100% of the speed achieved during VO 2 peak testing followed by 60s of walking at 4.02 km/h. BW-HIIE consisted of two sets of 5, 60s ‘all-out’ effort calisthenic exercises followed by 60s of marching in place at 100 steps per minute. Oxygen consumption (VO 2 ), blood lactate (B lac ), heart rate (HR), and rating of perceived exertion (RPE) were measured during exercise. Physical activity enjoyment (PACES) was assessed post-exercise. Creatine Kinase (CK) was measured before exercise and 48-h post-exercise. Muscle soreness was assessed before exercise, post-exercise, and 48-h post-exercise. Results Oxygen consumption relative to VO 2 peak was higher ( p < 0.001) during RUN-HIIE (88 ± 3%) compared to BW-HIIE (77 ± 4%). HR relative to HRpeak was higher ( p = 0.002) for RUN-HIIE (93 ± 1%) compared to BW-HIIE (88 ± 2%). B lac was higher ( p < 0.001) after BW-HIIE (11.2 ± 3.2 mmol/l) compared to RUN-HIIE (6.9 ± 2.0 mmol/l). Average RPE achieved was higher ( p = 0.003) during BW-HIIE (16 ± 2) than RUN-HIIE (14 ± 2). PACES was similar for RUN-HIIE and BW-HIIE ( p > 0.05). No differences ( p > 0.05) in CK were observed between RUN-HIIE and BW-HIIE. Conclusion Our results indicate ‘all-out’ calisthenic exercise can elicit vigorous cardiorespiratory, B lac , and RPE responses. Implementing this style of exercise into training requires minimal space, no equipment, and may elicit cardiometabolic adaptations seen with traditional forms of high-intensity exercise.
... Extensive research has presented the enhanced health benefits of performing higher intensities of exercise [1]. High-intensity exercise participation has been demonstrated to promote greater cardiovascular health benefits when compared to low intensity exercise [2,3]. Indeed, exercise intensity has been established as the single most important aspect of aerobic exercise prescription in reducing cardiovascular death risk and all-cause mortality [4]. ...
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The second ventilatory threshold (VT2) is established as an important indicator of exercise intensity tolerance. A higher VT2 allows for greater duration of higher intensity exercise participation and subsequently greater reductions in cardiovascular disease (CVD) risk. This study aimed to compare the efficacy of standardised and individualised exercise prescription on VT2 among physically inactive adults. Forty-nine physically inactive male and female participants (48.6 ± 11.5 years) were recruited and randomised into a 12-week standardised (n = 25) or individualised (n = 24) exercise prescription intervention. The exercise intensity for the standardised and individualised groups was prescribed as a percentage of heart rate reserve (HRR) or relative to the first ventilatory threshold (VT1) and VT2, respectively. Participants were required to complete a maximal graded exercise test at pre-and post-intervention to determine VT1 and VT2. Participants were categorised as responders to the intervention if an absolute VT2 change of at least 1.9% was attained. Thirty-eight participants were included in the analysis. A significant difference in VT2 change was found between individualised (pre vs. post: 70.6% vs. 78.7% maximum oxygen uptake (VO2max)) and standardised (pre vs. post: 72.5% vs. 72.3% VO2max) exercise groups. Individualised exercise prescription was significantly more efficacious (p = 0.04) in eliciting a positive response in VT2 (15/19, 79%) when compared to the standardised exercise group (9/19, 47%). Individualised exercise prescription appears to be more efficacious than standardised exercise prescription in eliciting a positive VT2 change among physically inactive adults. Increasing VT2 allows for greater tolerance to higher exercise intensities and therefore greater cardiovascular health outcomes.
... Thereby, mainly two HIT protocols were commonly used in the literature. First, a Wingate-based "all-out" protocol [also called sprint interval training (SIT)] consisting of 4-6 × 30 s intervals, mainly used by the group of Gibala et al. [ 4 ] , and second, the 4 × 4 min protocol performed at intensities of 90-95 % of maximal heart rate, mainly used by Helgerud et al. [ 5 ] . However, up to now no study directly compared 4 × 30 s and 4 × 4 min with each other, and also a comparison with HVT is missing in this context. ...
... Today, researchers believe that participation in physical activities can be effective in improving the health of athletes or even people with diseases (Edge et al.,2006;Helgerud et al.,2006) While participating in these activities, especially exhaustive activities is accompanied to releasing free radicals (free radicals) and depletion of antioxidant resources that Lipid peroxidation and oxidative stress indices of blood and urine rises(increases), in fact, free radicals can cause inflammatory responses (Scott and Jackson Malcolm 2008). ...
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Introduction: Oxidative stress is a condition in which the reactive oxygen species production exceeds the antioxidant system capacity to neutralize these peroxidases. In these situations, proteins, lipids, and nucleic acids are damaged. In this regard, the cherry can be noted as a food antioxidant which leads an increasing antioxidant capacity and reducing inflammation and damage muscle. Therefore, The purpose of this study was to determine the effect of cherry juice supplementation on total antioxidant capacity (TAC), creatine kinase (CK), hydrogen peroxide (H 2 O 2) in non-athlete men after an exhaustive aerobic exercise. Method: In this quasi-experimental research, ten untrained (UT) men were randomly selected. Then, they were divided into two equal groups: supplement group (cherry juice) and placebo group (commercial Cherry juice diluted with natural water). After eight days of supplementation period, all subjects were participated in aerobic exercise protocol (Bruce test run to the point of exhaustion) on the treadmill. Primary blood samples in the baseline were taken. The second was immediately after the Bruce test, third and fourth were six and twenty-four hours later were taken (5 ml). For analysis of the results. Analysis of variance with repeated measures was used at the significant level. Result: A significant effect of short-term cherry juice supplementation on TAC, H 2 O 2, and CK was observed (p≤0.05). Conclusions: In general, it can be concluded that probably eight days of cherry juice supplementation probably cannot prevent the adverse effects of oxidative stress caused by acute aerobic exercise.
... Reducing body fat mass may mitigate the likelihood of developing cardiorespiratory disease and diabetes, as adipose tissue is a precursor to these conditions [57]. Central (increased stroke volume) and peripheral adaptations (increased capillary density and mitochondrial adaptation) may be responsible for the increase in cardiorespiratory fitness elicited by high-intensity exercise [58][59][60]. Therefore, once medically cleared to undertake regular PA, exoskeleton walking may enable individuals with neurological impairments to exercise at a high intensity, and promote more favourable cardiorespiratory fitness and body composition adaptations than an arm crank or wheelchair ergometer can, as exoskeleton walking may elevate thoracohumeral and trunk muscle mass activation rather than isolating the upper extremities [14]. ...
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Individuals with neurological impairments tend to lead a predominantly sedentary lifestyle due to impaired gait function and mobility. This may be detrimental to health by negatively impacting cardiorespiratory fitness and muscular strength, and increasing the risk of developing secondary health problems. Powered exoskeletons are assistive devices that may aid neurologically impaired individuals in achieving the World Health Organisation’s (WHO) physical activity (PA) guidelines for health. Increased PA should elicit a sufficient cardiorespiratory stimulus to provide health benefits to exoskeleton users. This study examined the cardiorespiratory demands of treadmill walking with and without the Ekso GT™ among able-bodied participants. The Ekso GT™ is a powered exoskeleton that enables individuals with neurological impairments to walk by supporting full body mass with motors attached at the hip and knee joints to generate steps. This feasibility study consisted of one group of healthy able-bodied individuals (n = 8). Participants completed two 12 min treadmill walking assessments, one with and one without the Ekso GT™ at the same fixed speed. Throughout each walking bout, various cardiorespiratory parameters, namely, volume of oxygen per kilogram (kg) of body mass (V˙O2·kg−1), volume of carbon dioxide per kg of body mass (V˙CO2·kg−1), respiratory exchange ratio (RER), ventilation (V˙E), heart rate (HR), and rate of perceived exertion (RPE), were recorded. Treadmill walking with Ekso GT™ elevated all recorded measurements to a significantly greater level (p ≤ 0.05) (except RER at 1 km·h–1; p = 0.230) than treadmill walking without the Ekso GT™ did at the same fixed speed. An increased cardiorespiratory response was recorded during treadmill walking with the exoskeleton. Exoskeleton walking may, therefore, be an effective method to increase PA levels and provide sufficient stimulus in accordance with the PA guidelines to promote cardiorespiratory fitness and subsequently enhance overall health.
... During intense physical training, physical stress and homeostasis alterations occur when the body exceeds 60% of the maximal oxygen consumption (VO 2max ) or if the duration of the exercise exceeds 90 min (even when the intensity does not exceed 40% VO 2max ), leading to activation of the HPA axis [89,90]. Similarly, in the precompetition periods, athletes face high levels of psychological stress that also trigger the HPA axis with similar consequences on the microbiota profile. ...
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Gut microbiota refers to those microorganisms in the human digestive tract that display activities fundamental in human life. With at least 4 million different bacterial types, the gut microbiota is composed of bacteria that are present at levels sixfold greater than the total number of cells in the entire human body. Among its multiple functions, the microbiota helps promote the bioavailability of some nutrients and the metabolization of food, and protects the intestinal mucosa from the aggression of pathogenic microorganisms. Moreover, by stimulating the production of intestinal mediators able to reach the central nervous system (gut/brain axis), the gut microbiota participates in the modulation of human moods and behaviors. Several endogenous and exogenous factors can cause dysbiosis with important consequences on the composition and functions of the microbiota. Recent research underlines the importance of appropriate physical activity (such as sports), nutrition, and a healthy lifestyle to ensure the presence of a functional physiological microbiota working to maintain the health of the whole human organism. Indeed, in addition to bowel disturbances, variations in the qualitative and quantitative microbial composition of the gastrointestinal tract might have systemic negative effects. Here, we review recent studies on the effects of physical activity on gut microbiota with the aim of identifying potential mechanisms by which exercise could affect gut microbiota composition and function. Whether physical exercise of variable work intensity might reflect changes in intestinal health is analyzed.
... The magnitude of the reported increase in absolute V O2max should also be contextualized against other controlled interventions of similar duration. For instance, untrained subjects undertaking eight weeks of endurance exercise training exhibited increases in V O2max in the region of 7 -18% [1][2][3][4], while 11 weeks administration of erythropoietin (EPO)a potent stimulus for red blood cell production, widely utilized as a doping agent in endurance sport -improved V O2max in untrained subjects by 12% [5]. Moreover, the increase in V O2max reported by Medeiros et al. is ~3-fold greater than would be anticipated given the documented association between serum vitamin D concentrations and cardiorespiratory fitness [6]. ...
... Consequently, the CE70 lasted in total for 45 min, while the INT80 and INT90 lasted 38 min. The CE70 and INT90 sessions are matched in terms of work (energy expenditure) (Helgerud et al., 2007), and the INT90 and INT80 sessions by time. The participants were unaware of their randomized exercise session until they showed up in the laboratory each day. ...
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Introduction: Exercise at high intensity may cause lower affective responses toward exercise compared with moderate intensity exercise. We aimed to elucidate affective valence and enjoyment in high-and moderate-high interval exercise. Methods: Twenty recreationally active participants (9 females, 11 males, age range: 20-51 years) underwent three different treadmill running exercise sessions per week over a 3-week period, in randomized order; (1) CE70: 45 min continuous exercise at 70% of heart rate maximum (HR max), (2) INT80: 4 × 4 min intervals at 80% of HR max , (3) INT90: 4 × 4 min intervals at 90% of HR max. Pre-tests included graded submaximal steady state intensities and a test to exhaustion for determining peak oxygen uptake and HR max. Affective valence (pleasure/displeasure) was measured before, during and after the sessions using the Feeling Scale (FS). Enjoyment was assessed before and after the sessions applying the Physical Activity Enjoyment Scale (PACES) and during the sessions using the Exercise Enjoyment Scale (EES). Results: The participants felt lower pleasure (between-sessions effect: p = 0.02, p η 2 : 0.13) during INT90 sessions (FS: 1.08, 95% CI: 0.35-1.92) compared with INT80 (FS: 2.35, 95% CI: 1.62-3.08, p = 0.052) and CE70 sessions (FS: 2.45, 95% CI: 1.72-3.18, p = 0.03), with no differences between INT80 and CE70 sessions (p = 1.00). There were higher enjoyment after INT80 sessions (PACES: 101.5, 95% CI: 95.7-107.3) versus CE70 sessions (PACES: 91.3 95% CI: 85.5-97.1, p = 0.046), and no differences between INT90 (PACES: 98.2, 95% CI: 92.4-103.4) and CE70 (p = 0.29) or INT80 (p = 1.00). For enjoyment during exercise, CE70 were perceived more enjoyable, and INT80 and INT90 less enjoyable in week 2 (EES: week x session: p = 0.01, p η 2 : 0.11; CE70: 4.3, 95% CI: 3.6-4.9, INT80: 4.6, 95% CI: 3.9-5.2, INT90: 4.0, 95% CI: 3.4-4.7) and 3 (EES: CE70: 4.2, 95% CI: 3.7-4.8, INT80: 4.8, 95% CI: 4.2-5.3, INT90: 4.3, 95% CI: 3.8-4.9) than in week 1 (EES: CE70: 3.5, 95% CI: 3.0-4.0, INT80: 5.0, 95% CI: 4.5-5.5, INT90: 4.5, 95% CI: 4.0-5.0). Conclusion: The negative affective consequences associated with high intensity interval exercise can be alleviated by keeping the intensity at or around 80% of HR max while preserving the beneficial enjoyment responses associated with interval exercise.
... The training of players specializing in longer distances differs in nature and purpose from sprint training. The goal of long-distance swimmers is to improve the maximum oxygen uptake (VO 2 max), which increases the baseline cardiac output volume but also to raise the number and size of mitochondria and much more 37,38 . The lack of access to swimming pools and training in water, which is based on oxygen metabolism in natural conditions of competition, could significantly affect the results of medium distances compared to sprint distanc-es. ...
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Objective: This article aims to conduct a comparison of swimming performance during short course national championships (25-m) from 2019 and 2020 (before and during the pandemic). Materials and methods: The data points from the championships will be compared for 5 European countries: Poland, Spain, Russia, Turkey, and Denmark. Times achieved in the finals were calculated by the analysis of variance. Post hoc pairwise comparison analysis was performed using Tukey's test. The analysis plan included the assessment of the main effects and the effect of interactions in the groups of women and men. The strength of the effect was expressed by the partial eta-squared ratio. Results: Two main trends were observed in the results. The first was a greater variation in the results in the group of men than in women (12-5 differences). The second was the development and improvement of sports performance in symmetrical strokes (69% improvement in recorded times measured during the pandemic, e.g., in Poland, women on 50-m breaststroke and butterfly Δ = 0.52, p <0.001 and Δ = 0.32, p = 0.034, men on 50-m and 100-m butterfly Δ = 0.34, p = 0.003 and Δ = 1.21, p <0.001). Conclusions: The main conclusion of our analysis is that the pandemic influenced the development of sports performance in symmetrical techniques, i.e., in breaststroke and butterfly.
... Blood pressure was not affected by exercise training. Family physician according, Helgerud et al., (2007) studied effect of high intensity (90-95% HRmax) and moderate intensity (70-85% HRmax) exercises on VO2max in 40 healthy, physically active and non-smoking subjects. The subjects exercised three times a week for eight weeks. ...
... Each bout is interspersed by a 3 min active resting period performing at 70% of HR max . 54 The session will end with a 5 min cool-down period of low-intensity workload. Total treadmill time per session is 40 min. ...
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Introduction Patients with substance use disorder (SUD) have high prevalence of lifestyle-related comorbidities. Physical exercise is known to yield substantial prophylactic impact on disease and premature mortality, and there seems to be an inverse association between physical fitness and adverse health outcomes. High-intensity training is regarded as most effective for improving physical fitness, but less is known concerning the ideal training dose necessary to achieve clinically relevant effects in these patients. The aim of this study is to compare the effect of low-dose and high-dose, high-intensity training, on physical fitness in patients diagnosed with SUD. Methods and analysis This study will recruit 40 in-patients of mixed genders, aged 18–70 years. Participants will be block allocated to low-dose or high-dose training, encompassing 24 high-intensity interval and maximal strength training sessions (3/week × 8 weeks). After a 10 min warm-up, the low-dose group will perform 1×4 min intervals at ⁓90% of maximal heart rate and 2×4 repetitions strength training at ⁓90% of 1 repetition maximum. The high-dose group will perform 4×4 min intervals at ⁓90% of maximal heart rate and 4×4 repetitions strength training at ⁓90% of 1 repetition maximum. Clinical measurements and physical tests will be conducted at baseline, midway and on completion and a questionnaire on physical activity will be administered at baseline. Ethics and dissemination This protocol is in accordance with the Standard Protocol Items: Recommendations for Interventional Trials statement. All participants will sign a written informed consent. The Regional Committee of Medical Research Ethics, Norway has approved the study. A study of this kind is warranted, and the results will be published in an open access journal to ensure public access, and presented at national and international conferences. Trial registration number NCT04065334 .
... Notably, the term HIIT is not consistently defined, and multiple descriptions and exercise protocols are used [15]. In the current literature, a range of protocols are employed, which consist of exercise bouts lasting a few seconds and intensities close to maximum [16] and bouts lasting up to 4 min and correspondingly lower intensities [17,18]. The differences in the training variables are expected to reflect changes in the metabolism and adaptations of organic systems [19]. ...
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In light of the global physical inactivity pandemic, the increasing prevalence of non-committable diseases, and mounting healthcare costs, effective and feasible prevention and treatment approaches are urgently needed [...]
... Interestingly, both groups surpassed the average 10,000 steps/day, indicating that both were physically active. However, step count does not relate to exercise intensity and this might explain the lack of improvements in either group regarding cardiorespiratory fitness, where a combined intervention with aerobic training, perhaps of high intensity [65], could have yielded significant fitness improvements. Shoulder mobility (i.e., flexion) was also not improved in the RTG compared to the CG. ...
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Purpose: This study assessed the effects of 12-week supervised resistance training combined with home-based physical activity on physical fitness, cancer-related fatigue, depressive symptoms, health-related quality of life (HRQoL), and life satisfaction in female breast cancer survivors. Methods: A parallel-group, outcome assessor-blinded, randomized controlled trial included 60 female breast cancer survivors who had completed their core treatments within the previous 10 years. Through computer-generated simple rand-omization, participants were assigned to resistance training (RTG; two sessions/week for 12 weeks plus instructions to undertake ≥ 10,000 steps/d) or control (CG; ≥ 10,000 steps/d only). Outcomes were evaluated at baseline and week 12. Muscular strength was assessed with electromechanical dynamometry. A standardized full-body muscular strength score was the primary outcome. Secondary outcomes included cardiorespiratory fitness, shoulder mobility, cancer-related fatigue, depressive symptoms, HRQoL, and life satisfaction. Results: Thirty-two participants were assigned to RTG (29 achieved ≥ 75% attendance) and 28 to CG (all completed the trial). Intention-to-treat analyses revealed that the standardized full-body muscular strength score increased significantly in the RTG compared to the CG (0.718; 95% CI 0.361-1.074, P < 0.001, Cohen's d = 1.04). This increase was consistent for the standardized scores of upper-body (0.727; 95% CI 0.294-1.160, P = 0.001, d = 0.87) and lower-body (0.709; 95% CI 0.324-1.094, P = 0.001, d = 0.96) strength. There was no effect on cardiorespiratory fitness, shoulder flexion, cancer-related fatigue, depressive symptoms, HRQoL, or life satisfaction. The sensitivity analyses confirmed these results. Conclusion and implication for cancer survivors: In female breast cancer survivors who had completed their core treatments within the past 10 years, adding two weekly sessions of supervised resistance training to a prescription of home-based physical activity for 12 weeks produced a large increase in upper-, lower-, and full-body muscular strength, while other fitness components and patient-reported outcomes did not improve. Trial registration number: ISRCTN14601208.
... HIIT has been the subject of several clinical studies, showing improvements in metabolic [6], physical [7,8] and cognitive [9] levels within a variety of groups of patients. The maximum rate of oxygen consumption (VO 2 peak) in HIIT is significantly higher than in MCT [10][11][12][13]. ...
Article
Background With an increasing number of inpatients in geriatric rehabilitation, there is continuing interest in efficient training measures regarding physical performance.Objectives To examine the feasibility and outcomes of high-intensity interval training (HIIT) in geriatric patients. Methods Single-centre randomized controlled study of HIIT vs. moderate continuous training (MCT) for patients ≥65 years old referred to inpatient rehabilitation. Cardiopulmonary exercise testing (CPET) was performed before the first and last training in order to measure participant’s cardiorespiratory fitness. At the same time-points patients completed a series of questionnaires regarding subjective improvements and acceptance of the training methods. Results Regarding feasibility, HIIT showed a completion rate of 82.4% and an adherence rate of completed sessions of 83.3%. HIIT significantly improved cardiorespiratory fitness (+13% for VO2peak, p=0.01), respiratory quotient (+9%, p=0.01) and power output (+12% for Watt peak, p=0.01) compared with MCT. Significant improvements were also seen over time for physical and mental scores of PROMIS-10 and quality of life. Conclusion A HIIT intervention has proven feasible for elderly patients in a geriatric rehabilitative setting. Further research should specify the HIIT intervention in order to offer this training to more patients. Long-term observations are also needed.
... One of them is High-Intensity Interval Training (HIIT), a combination of highintensity and low-intensity physical training (6,7). Recent studies have shown that HIIT improves body composition (8,9) and cardiopulmonary fitness (10)(11)(12). ...
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Background. Continuous Training (CT) is often considered an effective way to reduce obesity. However, recently, a popular protocol called High-Intensity Interval Training (HIIT) has shown up as an alternative to CT. There is another factor affecting obesity named UCP2 45-bp Insersion/Deletion genetic marker. Objectives. This research aims to determine the effect of the UCP2 45-bp I/D gene as a genetic marker in response to obese training (CT and HIIT). Methods. This study was a randomized controlled trial (RCT) in two cycling training groups (CT and HIIT). The purposive sampling method was used to collect 28 women with obesity (BMI≥25 kg/m2). Random allocation into two groups using the block randomization method. Exercise training interventions were conducted for 12 weeks, with a frequency of 3 times per week. Results. Body composition data (body weight, BMI, and Body Fat Percentage) before and after the intervention were analyzed with the Dependent T-Test and found that both the CT and HIIT groups had significant improvements in body composition (P<0.05). ANCOVA Test analyzed the effect of training type and UCP2 45-bp I/D variance on body composition. There was no effect of training type and genetic variation on body weight improvement (P=0.145), body mass index improvement (P=0.153), and body fat improvement (P=0.159). Conclusion. Both Continuous and High-Intensity Interval Training can equally improve the body composition of obese patients. There was no UCP2 45-bp I/D variance effect on the response to training in a woman with obesity.
... Studies investigating the relationship between PA and psychotropics use have showed a reduced risk of purchasing psychotropics by increasing physical activity levels with the lowest risk among those showing PA pattern of moderate to vigorous intensity of high volume [23]. The latter finding indicate that intensity could be an important PA dimension for psychotropics reduction and is also shown to be a key factor to increase VO 2peak [34,35] . ...
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Background The use of psychotropics is high among the older population and may have detrimental effects on their physical and mental health. Cardiorespiratory fitness (CRF) is a strong and modifiable measure of health and declines with age. We aimed to study the association of change in CRF with use of psychotropics in community-dwelling older adults. Methods We analyzed longitudinal data from 1531 older adults from the Generation 100 study, aged 70–77 years at inclusion, and with a permanent address in Trondheim, Norway. Data on objectively measured peak oxygen uptake (VO 2peak ) were linked with register data from the Norwegian Prescription Database on prescribed psychotropics. The included psychotropics were antidepressants (N06A), antipsychotics (N05A), anxiolytics (N05B), hypnotics and sedatives (N05C), and N03AE (benzodiazepine derivatives). Analyses were done on any psychotropics as one group, and on the following separate groups: antidepressants (N06A), benzodiazepines (N05BA, N05CD, and N03AE), and z-hypnotics (N05CF). Peak oxygen uptake was measured four times over a five-year period and corresponding medication use was measured as defined daily doses (DDD). A random effects estimator was applied to investigate the association of change in VO 2peak with the use of psychotropics. Results We found a statistically significant curvilinear association of change in VO 2peak with use of any psychotropics and antidepressants. For VO 2peak up to ~ 40 ml/kg/min, each 1 ml/kg/min increase was associated by a 3.3 DDD and 2.5 DDD decrease in use of any psychotropics and antidepressants, respectively. A bottoming-out effect was found and increases in VO 2peak above ~ 40 ml/kg/min showed increased use of any psychotropics and antidepressants. However, the association of change in VO 2peak with use was stronger for changes in the lower continuum of VO 2peak levels and decreased with increasing VO 2peak . No statistically significant association of change in VO 2peak with use of benzodiazepines and z-hypnotics were found. However, because of a non-randomized design, we cannot rule out the possibility of confounding by indication. Conclusions The results of this study show a curvilinear association of change in VO 2peak with use of any psychotropics and antidepressants in older adults. This relationship adds a new viewpoint on the adverse effects of psychotropic use and should be considered in interventions and policies aimed at reducing psychotropic medication use among the older population.
... be defined more generally as a combination of periods in which high-intensity load (load interval = LI) alternate with low-intensity exercise or passive rest, the so-called rest interval (RI) or inactive phase (Gibala et al., 2006;Helgerud et al., 2007;. High intensity in the active phase is key to the effectiveness of the method and has been discussed by many experts. ...
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High Intensity Interval Training is a training method based on a combination of periods in which high-intensity load alternate with low-intensity exercise or passive rest, the so-called rest interval or inactive phase. Nowadays it is gaining more popularity among the general population and is applied in modern fitness centers. The authors found that more than 95 % sports centers organizing group lessons in Brno offer some form of HIIT (“Tabata System”, especially). Changing one of the HIIT components will affect the efficiency of the whole system. This effect is demonstrable on the aerobic and anaerobic performance and the composition of body tissues. Our goal within the broad research is to find out what effect changing one variable has on the most widely used HIIT program, and we wanted to examine whether the method is suitable for recreational athletes.The authors have made the first step in the form of pilot research described in this article, trying to design the system and applying the components in it. The experiment involved twenty deliberately selected male probands. They were randomly divided into two intervention groups of ten probands. In both intervention groups, we observed: number of repetitions performed, subjective load assessment (on the Borg scale) and heart rate. The original design of the pilot study included three training units per week for two weeks (a total of six training units). Basic multiple articulated exercises (Burpees and Jump Squats) were selected for both sets in these protocols in order to achieve key intensity for HIIT. There were some limitations of the experiment described in the article.The result of the first pilot study was essential concerning the adequacy of the cycle settings. The authors were forced to stop the piloting after the completion of the first week due to the acute overtraining of the probands. The reason to stop the experiment is attributed to an inadequate frequency of training units in individual weeks, which we reflected in the design of the following pilot study and reduced the number to two. The authors have kept the research questions and present the results of the modified piloting below.It can be assumed that the prolongation of the rest interval has an impact on the ability to perform repeated exercises, heart rate and subjective perception of stress in selected exercises. These results of our pilot research are also related to people's desire to get as much as possible in as little (time) as possible. The HIIT method is (in many aspects) more effective than the continuous method. Its undeniable advantage is time saving, but efficiency is "redeemed" by intensity and demanding character (proved not just in the described experiments). Where is the line between benefit sport and health-threatening sport? What is the "correct" HIIT setting/programming and what causes a change in one of the key variables? Is less sometimes more or more demanding means more effective? Respecting people's demands and desires for performance, mental fitness and physical beauty, with regard to sustainability and health above all, we will seek answers to all these questions. The first step towards finding them is the study carried out.
... High-intensity interval training (HIIT) has been documented as a safe and effective training method for cardiac rehabilitation [21]. HIIT can be defined as a short burst of maximal effort interspersed by a few minutes of rest or active recovery, and it has been reported to be more effective than CMT for improving cardiorespiratory fitness in different populations [16][17][18][22][23][24]. HIIT, which consists of several bouts of high-intensity exercise (85-95% of HRmax) lasting 1 to 4 min interspersed with intervals of rest or active recovery [15,17,18], has been found to improve endothelial function and its markers [16,18], insulin sensitivity [18], markers of sympathetic activity [16,17], arterial stiffness [15,16], blood glucose and lipoproteins [18]. ...
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The likelihood of pre-hypertensive young adults developing hypertension has been steadily increasing in recent years. Despite the fact that aerobic exercise training (AET) has demonstrated positive results in lowering high blood pressure, the efficacy of different types of AET among pre-hypertensive young adults has not been well-established. The objective of this study was to evaluate the effectiveness of high-intensity interval training (HIIT) and continuous moderate-intensity training (CMT) on the blood pressure (BP) of physically inactive pre-hypertensive young adults. In total, 32 adults (age 20.0 ± 1.1 years and BMI 21.5 ± 1.8) were randomly assigned to three groups: HIIT, CMT and control (CON). The HIIT and CMT groups participated in 5 weeks of AET, while the CON group followed a DASH diet plan only. The HIIT protocol consisted of a 1:4 min work to rest ratio of participants, at an 80–85% heart rate reserve (HR-reserve) and a 40–60% HR-reserve, respectively, for 20 min; the CMT group exercised at 40–60% of their HR-reserve continuously for 20 min. In both the HIIT and CMT groups, systolic blood pressure (SBP) (3.8 ± 2.8 mmHg, p = 0.002 vs. 1.6 ± 1.5 mmHg, p = 0.011) was significantly reduced, while significant reductions in the diastolic blood pressure (DBP) (2.9 ± 2.2 mmHg, p = 0.002) and mean arterial pressure (MAP) (3.1 ± 1.6 mmHg, p < 0.0005) were noted only in the HIIT group. No significant differences in SBP (−0.4 ± 3.7 mmHg, p = 0.718), DBP (0.4 ± 3.4 mmHg, p = 0.714), or MAP (0.1 ± 2.5 mmHg, p = 0.892) were observed in the CON group. Both HIIT and CMT decreased BP in physically inactive pre-hypertensive young adults; however, HIIT yielded more beneficial results in terms of reducing the SPB, DBP and MAP.
... Ainsi, en augmentant le V̇O !"#$ou la fraction du V̇O !"#$ soutenue lors de l'effort, ou en diminuant le CE de la course, ou encore en combinant ces trois paramètres, la performance peut être améliorée. Toutefois, ces facteurs physiologiques clés de la course à pied (i.e., le V̇O !"#\$ , l'économie de course et capacité d'endurance aérobie) dépendent également d'adaptations liées à l'entraînement (e.g., augmentation du VES, de la densité capillaire…) où les athlètes pourront être en mesure de développer une plus grande vitesse de course ou de maintenir une vitesse donnée sur une plus longue durée [33,68,130,137,154,155] ; mais aussi de caractéristiques individuelles comme l'âge, le sexe et l'IMC [15,17,22,116,141,144]. ...
Thesis
Cette thèse avait pour objectif de présenter les différents travaux réalisés sur la prédiction de la performance en course à pied afin d’aider les athlètes et les entraîneurs à optimiser leur processus d’entraînement. Ces études, en collaboration avec la Fédération Française d’Athlétisme (FFA), se sont appuyées sur le système d’information fédéral répertoriant notamment l’ensemble des résultats athlétiques, les bilans ou encore le nombre de licenciés. La première étude avait pour objectif d’exposer l’évolution des performances françaises des courses de demi-fond et de fond chez les femmes. Les études suivantes étaient principalement destinées à tester la validité, la justesse, et la précision de différentes méthodes de prédiction (i.e., capacité à prédire les performances) sur des performances individuelles réelles d’athlètes de différents niveaux, hommes et/ou femmes. Les résultats se sont avérés valides et précis, quelle que soit la méthode de prédiction utilisée. Enfin, la dernière recherche était destinée à la prédiction du potentiel de performance. Cette étude a notamment mis en avant une analyse du taux d'amélioration des performances en demi-fond et en fond précédant la réalisation de records personnels chez les hommes et chez les femmes. Un index de progression à visée pratique, a également été proposé, afin d’évaluer l’évolution des performances et permettre une éventuelle détection et orientation des athlètes au fort potentiel.
... High-intensity interval training (HIIT) has been documented as a safe and effective training method for cardiac rehabilitation [21]. HIIT can be defined as a short burst of maximal effort interspersed by a few minutes of rest or active recovery, and it has been reported to be more effective than CMT for improving cardiorespiratory fitness in different populations [16][17][18][22][23][24]. HIIT, which consists of several bouts of high-intensity exercise (85-95% of HRmax) lasting 1 to 4 min interspersed with intervals of rest or active recovery [15,17,18], has been found to improve endothelial function and its markers [16,18], insulin sensitivity [18], markers of sympathetic activity [16,17], arterial stiffness [15,16], blood glucose and lipoproteins [18]. ...
Article
Full-text available
The likelihood of pre-hypertensive young adults developing hypertension has been steadily increasing in recent years. Despite the fact that aerobic exercise training (AET) has demonstrated positive results in lowering high blood pressure, the efficacy of different types of AET among pre-hypertensive young adults has not been well-established. The objective of this study was to evaluate the effectiveness of high-intensity interval training (HIIT) and continuous moderate-intensity training (CMT) on the blood pressure (BP) of physically inactive pre-hypertensive young adults. In total, 32 adults (age 20.0 ± 1.1 years and BMI 21.5 ± 1.8) were randomly assigned to three groups: HIIT, CMT and control (CON). The HIIT and CMT groups participated in 5 weeks of AET, while the CON group followed a DASH diet plan only. The HIIT protocol consisted of a 1:4 min work to rest ratio of participants, at an 80–85% heart rate reserve (HR-reserve) and a 40–60% HR-reserve, respectively, for 20 min; the CMT group exercised at 40–60% of their HR-reserve continuously for 20 min. In both the HIIT and CMT groups, systolic blood pressure (SBP) (3.8 ± 2.8 mmHg, p = 0.002 vs. 1.6 ± 1.5 mmHg, p = 0.011) was significantly reduced, while significant reductions in the diastolic blood pressure (DBP) (2.9 ± 2.2 mmHg, p = 0.002) and mean arterial pressure (MAP) (3.1 ± 1.6 mmHg, p < 0.0005) were noted only in the HIIT group. No significant differences in SBP (−0.4 ± 3.7 mmHg, p = 0.718), DBP (0.4 ± 3.4 mmHg, p = 0.714), or MAP (0.1 ± 2.5 mmHg, p = 0.892) were observed in the CON group. Both HIIT and CMT decreased BP in physically inactive pre-hypertensive young adults; however, HIIT yielded more beneficial results in terms of reducing the SPB, DBP and MAP.
... Hence, two identical training sessions that occur at different training stages would induce similar adaptations and responses. Besides, various training sessions (e.g. a low intensity and prolonged exercise, and high intensity and short exercise) may result in similar TL estimates and so Fitness and Fatigue states, despite specific responses and adaptations to exercise exist [23,24]. For example, two resistance training sessions (a low intensity, high volume and a high intensity, low volume) may lead to similar TL indexes according to the product of exercise volume and intensity [19]. ...
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The emergence of the first Fitness-Fatigue impulse responses models (FFMs) have allowed the sport science community to investigate relationships between the effects of training and performance. In the models, athletic performance is described by first order transfer functions which represent Fitness and Fatigue antagonistic responses to training. On this basis, the mathematical structure allows for a precise determination of optimal sequence of training doses that would enhance the greatest athletic performance, at a given time point. Despite several improvement of FFMs and still being widely used nowadays, their efficiency for describing as well as for predicting a sport performance remains mitigated. The main causes may be attributed to a simplification of physiological processes involved by exercise which the model relies on, as well as a univariate consideration of factors responsible for an athletic performance. In this context, machine-learning perspectives appear to be valuable for sport performance modelling purposes. Weaknesses of FFMs may be surpassed by embedding physiological representation of training effects into non-linear and multivariate learning algorithms. Thus, ensemble learning methods may benefit from a combination of individual responses based on physiological knowledge within supervised machine-learning algorithms for a better prediction of athletic performance. In conclusion, the machine-learning approach is not an alternative to FFMs, but rather a way to take advantage of models based on physiological assumptions within powerful machine-learning models.
... High-intensity interval training (HIIT) allows a higher external validity with real combat scenarios (symmetrical, asymmetrical, or close quarter combat situations) and better physical outcomes. Furthermore, the use of reverse periodization allow lower volume and higher intensity, meaning lower rate of injury and more specific training [10][11][12], a more resilient psychophysiological profile [13] and greater adaptations for both tactical [14] and non-tactical athletes [15]. However, to our knowledge there are no studies that combine these elements, a reverse periodization training program, based on a HIIT that integrates military elements, thus an integral operative training (IOT). ...
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(1) Background. Military personel could be defined as “Tactical Athletes”. However, experimental evidence about the effects of new HIIT trainings in comparison with traditional training schedules is lacking. The aim of this study was to experimentally analyze the modifications on psycho-physiological and performance response of soldiers after completing experimental integral operative training. (2) Methods. A total of 43 male subjects of a special unit force of the Spanish armed forces were randomly selected and assigned into the experimental and control groups assessed after training and after deploying in a real operation area. The experimental group underwent an integral operative pre-mission 6-week training (IOT), and the control group, the 6-week traditional training. (3) Results. HIIT-based integral operative training significantly improved combat performance (melee combat score) and the psychophysiological stress response, as measured by heart rate variability indexes. (4) Conclusion. This study provides experimental evidence supporting a new integral operative effective for improved autonomic regulation, reduced perceived stress, melee and close-quarter combat techniques, in addition to aerobic and anaerobic performance and lower body strength in comparison with the traditional training.
... At the third visit, 2 weeks after the ST session, the participants took part in a HIIT session on a treadmill, as previously described (35). The participants were offered two packs of energy gel before this session. ...
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Context: Exercise is recognized as an important strategy to prevent bone loss, but its acute effects on bone turnover markers (BTMs) and related markers remain uncertain. Objective: To assess the acute effects of two different exercise modes on BTMs and related markers in young adults of both sexes and elderly men. Design, Setting, Participants: This was a three-group crossover within-subjects design study with a total of 53 participants—19 young women (aged 22–30), 20 young men (aged 21–30 years), and 14 elderly men (aged 63–74 years)—performing two different exercise sessions [strength training (ST) and high-intensity interval training (HIIT)] separated by 2 weeks, in a supervised laboratory setting. Main Outcome Measures: Plasma volume-corrected serum measurements of the BTMs C-terminal telopeptide of type 1 collagen (CTX-I) and procollagen of type 1 N-terminal propeptide (P1NP), total osteocalcin (OC), sclerostin, and lipocalin-2 (LCN2) at baseline, immediately after, and 3 and 24 h after each of the two exercise modes were performed. Results and Conclusion: Analyses revealed sex- and age-dependent differences in BTMs and related bone markers at baseline and time-, sex-, and age-dependent differences in response to exercise. No differences between exercise modes were observed for BTM response except for sclerostin in young men and LCN2 in elderly men. An acute, transient, and uniform increase in P1NP/CTX-1 ratio was found in young participants, demonstrating that beneficial skeletal effects on bone metabolism can be attained through both aerobic endurance and resistance exercise, although this effect seems to be attenuated with age. The acute effects of exercise on bone-related biomarkers were generally blunted after 24 h, suggesting that persistent alterations following prolonged exercise interventions should be assessed at later time points.
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For centuries, regular exercise has been acknowledged as a potent stimulus to promote, maintain, and restore healthy functioning of nearly every physiological system of the human body. With advancing understanding of the complexity of human physiology, continually evolving methodological possibilities, and an increasingly dire public health situation, the study of exercise as a preventative or therapeutic treatment has never been more interdisciplinary, or more impactful. During the early stages of the NIH Common Fund Molecular Transducers of Physical Activity Consortium (MoTrPAC) Initiative, the field is well-positioned to build substantially upon the existing understanding of the mechanisms underlying benefits associated with exercise. Thus, we present a comprehensive body of the knowledge detailing the current literature basis surrounding the molecular adaptations to exercise in humans to provide a view of the state of the field at this critical juncture, as well as a resource for scientists bringing external expertise to the field of exercise physiology. In reviewing current literature related to molecular and cellular processes underlying exercise-induced benefits and adaptations, we also draw attention to existing knowledge gaps warranting continued research effort. © 2021 American Physiological Society. Compr Physiol 12:3193-3279, 2022.
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The time sustained during exercise with oxygen uptake (V _ O 2) reaching maximal rates (V _ O 2peak) or near peak responses (i.e., above second ventilatory threshold [t@VT 2) or 90% V _ O 2peak (t@90%V _ O 2peak)] is recognized as the training pace required to enhance aerobic power and exercise tolerance in the severe domain (time-limit, t Lim). This study compared physiological and performance indexes during continuous and intermittent trials at maximal aerobic velocity (MAV) to analyze each exercise schedule, supporting their roles in conditioning planning. Twenty-two well-trained swimmers completed a discontinuous incremental step-test for V _ O 2peak , VT 2 , and MAV assessments. Two other tests were performed in randomized order, to compare continuous (CT) vs. intermittent trials (IT 100) at MAV until exhaustion, to determine peak oxygen uptake (Peak-V _ O 2) and V _ O 2 kinetics (V _ O 2 K). Distance and time variables were registered to determine the t Lim , t@VT 2 , and t@90%V _ O 2peak tests. Blood lactate concentration ([La − ]) was analyzed, and rate of perceived exertion (RPE) was recorded. The tests were conducted using a breath-by-breath apparatus connected to a snorkel for pulmonary gas sampling, with pacing controlled by an underwater visual pacer. V _ O 2peak (55.2 ± 5.6 ml·kg·min −1) was only reached in CT (100.7 ± 3.1 %V _ O 2peak). In addition, high V _ O 2 values were reached at IT 100 (96.4 ± 4.2 %V _ O 2peak). V _ O 2peak was highly correlated with Peak-V _ O 2 during CT (r = 0.95, p < 0.01) and IT 100 (r = 0.91, p < 0.01). Compared with CT, the IT 100 presented significantly higher values for t Lim (1,013.6 ± 496.6 vs. 256.2 ± 60.3 s), distance (1,277.3 ± 638.1 vs. 315.9 ± 63.3 m), t@VT 2 (448.1 ± 211.1 vs. 144.1 ± 78.8 s), and t@90%V _ O 2peak (321.9 ± 208.7 vs. 127.5 ± 77.1 s). V _ O 2 K time constants (IT 100 : 25.9 ± 9.4 vs. CT: 26.5 ± 7.5 s) were correlated between tests (r = 0.76, p < 0.01). Between CT and IT 100 , t Lim were not related, and RPE (8.9 ± 0.9 vs. 9.4 ± 0.8) and [La − ] (7.8 ± 2.7 vs. 7.8 ± 2.8 mmol·l −1) did not differ between tests. MAV is suitable for planning swimming intensities requiring V _ O 2peak rates, whatever the exercise schedule (continuous or intermittent). Therefore, the results suggest IT 100 as a preferable training schedule rather than the CT for aerobic capacity training since IT 100 presented a significantly higher t Lim , t@VT 2 , and t@90%V _ O 2peak (~757,~304, and~194 s more, respectively), without differing regards to [La − ] and RPE. The V _ O 2 K seemed not to influence t Lim and times spent near V _ O 2peak in both workout modes.
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Background and Aim: The prevalence of obesity is recognized as a health problem worldwide. Metabolic syndrome as the most important obesity factor is considered as one of the health problems in all societies. Supportive and complementary interventions are considered improvements in the status of individuals with metabolic syndrome. Therefore, the aim of this study was to investigate the effects of eight weeks of sodium alginate supplementation and high intensity interval training on lipid profiles and liver enzymes in metabolic syndrome women. Materials and Methods: Thirty women with metabolic syndrome were randomly assigned into 4 groups: intermittent exercise (High Intensity Interval Training)+supplement (n=9), intermittent exercise (HIIT) )n=8), complementary (n=7) and control group (n=6). Subjects in HIIT and HIIT + supplementation groups performed three sessions of intermittent exercise each week for eight weeks with an intensity of 85% to 95% of the maximum heart rate. Sodium alginate supplementation was taken three times a week and 30 minutes before meals in the amount of 1.5 g of sodium alginate dissolved in 100 mg of water. Blood sampling were taken from all 4 groups 48 hours before and after the exercise program. One-way ANOVA and t-test were used for data analysis (P≤0.05). Results: The results showed that in the exercise+supplement group lipid profile (P=0.005) and aspartate aminotransferase (P=0.012)(17.8%), fat percentage (P=0.001)(9.7%), BMI (P=0.000) and alanine aminotransferase (P=0.035)(12.7%) compared to the other group were significantly reduced, indicating the effect of intermittent exercise and supplementation on improving the symptoms of metabolic syndrome in women participating in this study. Conclusion: According to the results of this study, it seems that high intensity intermittent exercise with sodium alginate supplementation can be effective in prevention of some obesity related diseases and treatment of the metabolic syndrome
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The purpose of this case study was to examine the short-term development of performance and aerobic endurance following prolonged low-intensity ski trekking (LIST) in an Arctic region. Two male recreational athletes (aged 24 and 26 years) with high aerobic fitness performed LIST 7 ± 2 h·day ⁻¹ for 23 consecutive days, while hauling sledges (∼80 kg initially) with supplies from the north to the south of Svalbard (∼640 km). Time to exhaustion, maximal oxygen uptake (V̇O 2max ), lactate threshold (LT) and work economy were evaluated at pre- and post-trek. The results showed that the absolute and relative exercise intensity during LIST were ∼3.9 km·h ⁻¹ and ∼60% of maximal heart rate, respectively. Time to exhaustion during a ∼4–6 min ramp walking test, and a >45 min stepwise walking test, while pulling 12.5 kg weights (simulation of ski trekking with loaded sledge), increased by 11–17% and 3–9%, respectively, following LIST. Body mass and V̇O 2max relative to body mass (ml·kg ⁻¹ ·min ⁻¹ ) decreased by 5–8% and increased by 3–8%, respectively. Furthermore, the workload associated with LT and LT percentage of V̇O 2max increased by 39–69% and 12–13%, respectively. No notable change in work economy was observed. The mean pace during LIST (∼3.9 km·h ⁻¹ ) corresponded to the treadmill walking speed (4 km·h ⁻¹ ) with the lowest oxygen cost (mL·kg ⁻¹ ·m ⁻¹ ) in both participants. It can be concluded that short-term prolonged LIST can improve ski trek-simulated performance and fractional utilisation of V̇O 2max in recreational athletes with high aerobic fitness. Moreover, highly aerobically fit ski trekkers appear to instinctively choose the most energy-efficient pace during LIST.
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Introduction High-intensity interval training (HIIT) may improve cardiorespiratory fitness (CRF) and mental health. The current observer-blinded RCT investigates the sparsely studied efficiency of HIIT in reducing psychotic and non-psychotic symptoms in schizophrenia and complements previous studies by investigating whether symptom reduction following HIIT is associated with, putatively partly mediated by, increased VO 2 max. Methods Participants (outpatients meeting diagnostic criteria for schizophrenia) were randomized to HIIT ( n = 43) or a comparison group performing low-intensity active video gaming (AVG) to control for social interaction ( n = 39). Both interventions consisted of two supervised sessions/week for 12 weeks and a months of follow-up. Effects on overall symptoms and symptom domains [PANSS (0–6 scale), five-factor model] were estimated using mixed-effects models (intention-to-treat, n = 82). Underlying mechanisms were analyzed using moderated mediation analyses ( n = 66). We anticipated that HIIT would reduce overall symptoms, particularly depressive symptoms, more than AVG, and symptom reduction would be associated with, putatively mediated through, improved VO 2 max. Results Depressive symptoms (baseline score 3.97, 95% CI: 3.41, 4.52), were −1.03 points more reduced in HIIT than AVG at post-intervention (95% CI: −1.71, −0.35, p = 0.003), corresponding to a small to moderate effect size ( d = 0.37) and persisting at follow-up. There was a small reduction in overall symptoms, but no significant between-group differences were observed. Change in VO 2 max correlated negatively with the change in depressive symptoms. Mediation analysis showed a significant effect of change in VO 2 max on change in depressive symptoms within HIIT. The total effect was moderated by group, and depressive symptoms were more reduced in HIIT. Direct effects, not mediated through VO 2 max, were non-significant. Indirect effects, mediated through VO 2 max, were non-significant, but the moderated mediation test indicated a non-significant trend of 0.4 points (95% CI: −1.188, 0.087) and a larger reduction in depressive symptoms through VO 2 max in HIIT. Conclusion HIIT reduced depressive symptoms more than AVG, which persisted at follow-up. HIIT may serve as a complementing treatment option targeting these symptoms in individuals with schizophrenia, even before they reach clinical depression. Depressive symptoms are important to prevent, stabilize, and treat due to their negative implications for psychological wellbeing and long-term functional outcome. Reduction in depressive symptoms was associated with improved VO 2 max, and non-significant trends in the data supported that improved VO 2 max may be part of the complex mechanisms underlying the anti-depressive effect of HIIT. Clinical Trial Registration [ www.ClinicalTrials.gov ], identifier [NCT02205684].
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Zusammenfassung Onkologischen PatientInnen wird ein regelmäßiges körperliches Training explizit empfohlen. Das Hochintensive Intervalltraining (HIIT) rückt dank steigender Evidenzlage in unterschiedlichen Diagnosegruppen vermehrt in den Fokus der onkologischen Sport- und Bewegungstherapie. Die Betrachtung der aktuellen Literatur zeigt, dass das HIIT für Krebspatienten nach Abschluss der Therapie eine potenziell sichere sowie durchführbare Trainingsmethode ist. Darüber hinaus kann das HIIT positive Effekte auf die verringerte körperliche Leistungsfähigkeit von Krebspatienten haben. In diesem Zusammenhang ist sowohl das „4×4“- als auch das „10×1“-Protokoll mit onkologischen PatientInnen nach Abschluss der Therapie auf dem Fahrradergometer durchführbar, wobei insbesondere das „4×4“-Schema zur Realisierung von intensiven Trainingsreizen geeignet ist. Trotz zunehmender Untersuchungen bezüglich der Effekte von HIIT auf onkologische PatientInnen werden in diesem Forschungsbereich weitere qualitativ hochwertige Studien mit großer Teilnehmendenzahl benötigt.
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The aim of the present study was to monitor the pre-season preparatory training effectiveness by both the mood profile and physical performance. 15 male soccer players mean age 25±2.21 yr, height 180.27±2.58 cm, weight 81.13±5.49 kg and 5 years playing experience voluntary participated in this study. The program combined strength and endurance training, 4 weeks progressive training and t h e 5 th week declining activity (taper period). Assessments of mood and physical performances at first week, end of 4 th a n d 5 th weeks were performed. Variance of analysis with repeated measurements showed that the aerobic and anaerobic capacity did not change significantly after progressive training. But after taper period (the decline of training load) both indices increased significantly (p<0.05). However, the maximum strength, had significant increase during both the progressive training load and Beykzade, P () Beykzade@yahoo.com taper periods (p<0.05and p=0 .05 respectively). Four weeks progressive training load period; had insignificant effect on mood profile except for fatigue. After the taper period, fatigue and mood depression showed significant reduction compared to the beginning of the training period (p<0.05, p< 0.05 respectively). The o v e r a l l r e s u l t s s h o w t h a t a e r o b i c a n d anaerobic capacity compared to the reduction of training load is more sensitive than the time of progressive training load (p<0.05 for taper period and p>0.05 for time of progressive training load). Among the 6 mood factors, only fatigue and depression have been shown to be more sensitive to the change of training load.
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Purpose: Long-term development of endurance performance requires a proper balance between strain and recovery. While responses and adaptations to training are highly individual, this study examined whether individually-adjusted endurance training based on recovery and training status would lead to greater adaptations compared to a predefined program. Methods: Recreational runners were divided into predefined (PD, n = 14) or individualized (IND, n = 16) training groups. In IND, the training load was decreased, maintained or increased twice a week based on nocturnal heart rate variability, perceived recovery, and heart rate-running speed index. Both groups performed three-week preparatory, six-week volume and six-week interval periods. Incremental treadmill tests and 10 km running tests were performed before the preparatory period (T0) and after the preparatory (T1), volume (T2), and interval (T3) periods. The magnitude of training adaptations was defined based on the coefficient of variation between T0 and T1 tests (high >2 x, low <0.5 x). Results: Both groups improved (p < 0.01) their maximal treadmill speed (vMax) and 10 km time from T1 to T3. The change in the 10 km time was greater in IND compared to PD (-6.2 ± 2.8 % vs. -2.9 ± 2.4 %, p = 0.002). In addition, IND had more high responders (50 vs. 29 %) and fewer low responders (0 vs. 21 %) compared to PD in the change of vMax and 10 km performance (81 vs. 23% and 13 vs. 23 %) respectively. Conclusions: PD and IND induced positive training adaptations, but the individualized training seemed more beneficial in endurance performance. Moreover, IND increased the likelihood of high response and decreased the occurrence of low-response to endurance training.
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The purpose of this study was to investigate changes in the parameters of aerobic function resulting from continuous training (CT) and interval training of both low power (LPO-IT) and high power output (HPO-IT). Untrained males (n = 17, 25.1 yrs) trained 10 weeks on cycle ergometers (four 40-min sessions a week) at 80% VO2max. Cycle ramp function tests at 0 and 10 weeks were used to determine the four aerobic parameters:VO2max, ventilation threshold (VeT), effective time constant for O2 uptake kinetics (MRT), and work efficiency (eta): VO2max increased significantly (3.30 to 3.66 l.min-1). Absolute VeT increased significantly (2.17 to 2.45 l.min-1) but there was no change in the relative threshold (VeT/VO2max). MRT decreased significantly from 38.8 to 33.1 seconds and there was no change in eta. There were no between-group differences; thus neither low power output nor high power output interval training offers an advantage over continuous training of the same average power output in altering the aerobic parameters.
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This paper reviews the influence of several perturbations (physical exercise, heat stress, terrestrial altitude, microgravity, and trauma/sickness) on adaptations of blood volume (BV), erythrocyte volume (EV), and plasma volume (PV). Exercise training can induce BV expansion: PV expansion usually occurs immediately, but EV expansion takes weeks. EV and PV expansion contribute to aerobic power improvements associated with exercise training. Repeated heat exposure induces PV expansion but does not alter EV. PV expansion does not improve thermoregulation, but EV expansion improves thermoregulation during exercise in the heat. Dehydration decreases PV (and increases plasma tonicity) which elevates heat strain and reduces exercise performance. High altitude exposure causes rapid (hours) plasma loss. During initial weeks at altitude, EV is unaffected, but a gradual expansion occurs with extended acclimatization. BV adjustments contribute, but are not key, to altitude acclimatization. Microgravity decreases PV and EV which contribute to orthostatic intolerance and decreased exercise capacity in astronauts. PV decreases may result from lower set points for total body water and central venous pressure, while EV decreases may result from increased erythrocyte destruction. Trauma, renal disease, and chronic diseases cause anemia from hemorrhage and immune activation which suppresses erythropoiesis. The re-establishment of EV is associated with healing, improved life quality, and exercise capabilities for these injured/sick persons.
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The effects of low intensity endurance training on skeletal muscle capillary density and serum lipoprotein levels were studied in 11 non-obese men (18-25 years). The subjects performed a 6-week training regimen (60 min, 5 times per week) at the lactate threshold (LT). Capillary density was determined in biopsy specimens obtained from the vastus lateralis muscle before and after the training. The number of capillaries per fiber (cap/fiber ratio) before training was 1.97 +/- 0.47, and increased to 2.49 +/- 0.69 after training (p < 0.05). The maximal oxygen uptake (VO2 max) and LT- VO2 increased significantly by 5% (p < 0.01) and 27% (p < 0.01), respectively, whereas no change was observed in body weight. Low density lipoprotein cholesterol (LDL-C) tended to decrease (p = 0.06). The change in the cap/fiber ratio correlated inversely with the change in the ratio of LDL-C to high density lipoprotein cholesterol (HDL-C) (r = -0.61, p < 0.05). It was also, positively associated with the change in HDL2-C (r = 0.82, p < 0.01) and inversely associated with the change in HDL3-C (r = -0.63, p < 0.05). The change in LT- VO2 was inversely associated with the change in LDL-C (r = -0.62, r < 0.05). These results indicate that low intensity training increases capillary density in skeletal muscle, which may explain in part the changes in the lipoprotein profiles.
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Thesis (Ph.D.) -- Brigham Young University. Dept. of Physical Educational, 1999. Includes bibliographical references. cat
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Maximal oxygen uptake (V̇O2 max) has been described as an important characteristic of endurance athletes. Early investigations by Robinson, Edwards, and Dill, and Saltin and Astrand reported V̇O2 max values above 80 ml/kg.min for distance runners and cross-country skiers. Saltin and Astrand further documented a differentiation in V̇O2 max in a variety of athletic types. A more recent study showed that although V̇O2 max differentiated well in endurance athletes of diverse abilities, there was a limitation of using V̇O2 max to predict distance running performance of good runners. Costill et al. and Costill, Thomason, and Roberts found that the fractional utilization of VO2 at a standard running speed to be an important measure in predicting V̇O2 capacity in good distance runners. Running efficiency from the standpoint of energy expenditure may also be an important factor in differentiating distance runners. It has been suggested that differences may exist in some metabolic variables between elite marathon runners (26.2 miles or 42 km) and other elite types of middle-long distance runners (1-6 miles or 1,500-10,000 m). As metabolic and efficiency differences may prove more predictive in differentiating among elite runners, it was the purpose of this investigation to study the submaximal and maximal metabolic characteristics of a large sample of elite runners to observe if specific differentiation into the types of runner could be made.
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Maximal aerobic power of 37 athletes (14 females and ten male cross-country skiers, eight male rowers and five male cyclists) was determined during uphill running on the treadmill and during maximal performance of their specific sport activity. For the skiers a significantly (P less than 0.005) higher VO2max was found during uphill skiing than during running, the differences being 2.9 and 3.1% for the females and males, respectively. The rowers and cyclists obtained a difference of 4.2 and 5.6%, respectively (P less than 0.01). The largest individual differences between the two test procedures were 12.2, 5.4, 14.3, and 7.9% for female and male cross-country skiers, rowers, and cyclists, respectively. It is concluded that in evaluation of maximal aerobic power of atheletes, it becomes important to select a work situation which allows optimal use of the specifically trained muscle fibres. This means that the test preferably should be identical with the subjects' specific sport activity, under the assumption that a reasonably large muscle mass is engaged during the performance.
Six male and six female runners were chosen on the basis of age (20-30 years) and their performance over the marathon distance (mean time = 199.4, SEM 2.3 min for men and 201.8, SEM 1.8 min for women). The purpose was to find possible sex differences in maximal aerobic power (VO2max), anaerobic threshold, running economy, degree and utilization of VO2max (when running a marathon) and amount of training. The results showed that performance-matched male and female marathon runners had approximately the same VO2max (about 60 ml.kg-1.min-1). For both sexes the anaerobic threshold was reached at an exercise intensity of about 83% of VO2max, or 88%-90% of maximal heart rate. The females' running economy was poorer, i.e. their oxygen uptake during running at a standard submaximal speed was higher (P less than 0.05). The heart rate, respiratory exchange ratio and blood lactate concentration also confirmed that a given running speed resulted in higher physiological strain for the females. The percentage utilization of VO2max at the average marathon running speed was somewhat higher for the females, but the difference was not significant. For both sexes the oxygen uptake at average speed was 93%-94% of the oxygen uptake corresponding to the anaerobic threshold. Answers to a questionnaire showed that the females' training programme over the last 2 months prior to running the actual marathon comprised almost twice as many kilometers of running per week compared to the males (60 and 33 km, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
The energy demand of running on a treadmill was studied in different groups of trained athletes of both sexes. We have not found any significant differences in the net energy cost (C) during running (expressed in J.kg-1.m-1) between similarly trained groups of men and women. For men and women respectively in adult middle distance runners C = 3.57 +/- 0.15 and 3.65 +/- 0.20, in adult long-distance runners C = 3.63 +/- 0.18 and 3.70 +/- 0.21, in adult canoeists C = 3.82 +/- 0.34 and 3.80 +/- 0.24, in young middle-distance runners C = 3.84 +/- 0.18 and 3.78 +/- 0.26 and in young long-distance runners C = 3.85 +/- 0.12 and 3.80 +/- 0.24. This similarity may be explained by the similar training states of both sexes, resulting from the intense training which did not differ in its relative intensity and frequency between the groups of men and women. A negative relationship was found between the energy cost of running and maximal oxygen uptake (VO2max) expressed relative to body weight (for men r = -0.471, p less than 0.001; for women r = -0.589, p less than 0.001). In contrast, no significant relationship was found in either sex between the energy cost of running and VO2max. We conclude therefore that differences in sports performance between similarly trained men and women are related to differences in VO2max.kg-1. The evaluation of C as an additional characteristic during laboratory tests may help us to ascertain, along with other parameters, not only the effectiveness of the training procedure, but also to evaluate the technique performed.
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This review has grouped many studies on different populations with different protocols to show the interactive effects of intensity, frequency and duration of training as well as the effects of initial fitness levels and programme length on cardiorespiratory fitness as reflected by aerobic power (V̇O2max). Within each level of exercise duration, frequency, programme length or initial fitness level, the greatest improvements in aerobic power occur when the greatest challenge to aerobic power occurs i.e., when intensity is from 90 to 100% of V̇O2max. The pattern of improvement where different intensities are compared with different durations suggests that when exercise exceeds 35 minutes, a lower intensity of training results in the same effect as those achieved at higher intensities for shorter durations. Frequencies of as low as 2 per week can result in improvements in less fit subjects but when aerobic power exceeds 50 ml/kg/min, exercise frequency of at least 3 times per week is required. As the levels of initial fitness improve, the change in aerobic power decreases regardless of the intensity, frequency or duration of exercise. Although these pooled data suggest that maximal gains in aerobic power are elicited with intensities between 90 to 100% V̇O2 max, 4 times per week with exercise durations of 35 to 45 minutes, it is important to note that lower intensities still produce effective changes and reduce the risks of injury in non-athletic groups.
Maximal O2 consumption ($$\dot V_{O_{_2 max} }$$ and energy cost of running per unit distance (C) were determined on the treadmill in 36 male amateur runners (17 to 52 years) who had taken part in a marathon (42.195 km) or semi-marathon (21 km), their performance times varying from 149 to 226 and from 84 to 131 min, respectively.$$\dot V_{O_{_2 max} }$$ was significantly (2p<0.001) greater in the marathon runners (60.6 vs 52.1 ml · kg−1 · min−1) whileC was the same in both groups (0.179±0.017, S.D., mlO2 · kg−1 · m−1 above resting), and independent of treadmill speed. It can be shown that the maximal theoretical speed in endurance running (vEND) is set by$$\dot V_{O_{_2 max} }$$, its maximal sustainable fraction (F), andC, as described by:vEND=F ·$$\dot V_{O_{_2 max} }$$ ·C −1. SinceF was estimated from the individual time of performance,vEND could be calculated. The average speed of performance (vMIG) andvEND (m · s−1) were found to be linearly correlated:vMIG=1.12+0.64vEND (r 2=0.72;n=36). The variability ofvMIG explained byvEND, as measured byr 2, is greater than that calculated from any one regression betweenvMIG and$$\dot V_{O_{_2 max} }$$ (r 2=0.51),F ·$$\dot V_{O_{_2 max} }$$ (r 2=0.58), or$$\dot V_{O_{_2 max} }$$ ·C −1 (r 2=0.63). The mean ratio of observed (vMIG) to theoretical (vEND) speeds amounted to 0.947±0.076 and increased to 0.978±0.079 (±S.D.;n=36) when the effects of air resistance were taken into account. It is concluded thatvEND=F ·$$\dot V_{O_{_2 max} }$$ ·C −1 is a satisfactory quantitative description of the energetics of endurance running.
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To characterize the hemodynamic factors that regulate stroke volume during upright exercise in normal man, 24 asymptomatic male volunteers were evaluated by simultaneous right heart catheterization, radionuclide angiography, and expired gas analysis during staged upright bicycle exercise to exhaustion. From rest to peak exercise, oxygen consumption increased from 0.33 to 2.55 liters/min (7.7-fold), cardiac index increased from 3.0 to 9.7 liters/min per m2 (3.2-fold), and arteriovenous oxygen difference increased from 5.8 to 14.1 vol% (2.5-fold). The increase in cardiac index resulted from an increase in heart rate from 73 to 167 beats/min (2.5-fold), and an increase in left ventricular stroke volume index from 41 to 58 ml/m2 (1.4-fold). During low levels of exercise, there was a linear increase in cardiac index due to an increase in both heart rate and stroke volume index; stroke volume index increased as a result of an increase in left ventricular filling pressure and end-diastolic volume index and, to a much smaller extent, a decrease in end-systolic volume index. During high levels of exercise, further increases in cardiac index resulted entirely from an increase in heart rate, since stroke volume index increased no further. Left ventricular end-diastolic volume index decreased despite a linear increase in pulmonary artery wedge pressure; stroke volume index was maintained by a further decrease in end-systolic volume index. The degree to which stroke volume index increased during exercise in individuals correlated with the change in end-diastolic volume index (r = 0.66) but not with the change in end-systolic volume index (r = 0.07). Thus, the mechanism by which left ventricular stroke volume increases during upright exercise in man is dependent upon the changing relationship between heart rate, left ventricular filling, and left ventricular contractility. At low levels of exertion, an increase in left ventricular filling pressure and end-diastolic volume are important determinants of the stroke volume response through the Starling mechanism. At high levels of exertion, the exercise tachycardia is accompanied by a decrease in end-diastolic volume despite a progressive increase in filling pressure, so that stroke volume must be maintained by a decrease in end-systolic volume.
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Swedish military conscripts participated in 3 separate programs of interval training (principal activity - running): Group I (N = 20): 15 sec exercise + 15 sec rest, 3 days/week for 2 months. Group II (N = 9): 3 min exercise + 3 min rest, 3 days/week for 2 months, Group III (N = 8): 1 month no formal program, then 3 min exercise + 3 min rest, 5 days/week for 1 month. For each group, total time for exercise of high intensity = 15 min per session. Testing was performed on a cycle ergometer at induction, after 1 month, and after 2 months. Significant increases in max[latin capital V with dot above]o2 were observed for all groups (mean increase approximately 20%). Maximal oxygen uptake increased from 3.1, 2.9 and 3.2 to 3.6, 3.6 and 3.9 ] x min-1 for groups I, II and III, respectively. Concomitant reductions occurred in HR and perceived exertion at submaximal exercise (150 W). Individual improvement was inversely related to initial fitness, the lower the level at induction the greater the increase relative to this value. Subgroups tested 8 months after cessation of training (at discharge) had regressed to levels not different from those at induction. Conclusions: 1) physical fitness in this age group can be markedly and rapidly improved by interval training, 2) marked improvement in aerobic power capacity can be brought about by an impressively short time investment, 3) the training regimen based on 3-min periods was more effective than 15-sec periods, and 4) military life in this situation (communications regiment) was not sufficient to maintain a high level of fitness when the physical conditioning program was discontinued. (C)1973The American College of Sports Medicine
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Viable articular cartilage from the medial femoral condyles of rabbits was stored in vitro in tissue culture medium with various additives and the same site of each specimen was mechanically tested sequentially throughout a 12-day storage period. Indentation testing was performed with instantaneous and sustained loads. Preservation of sustained-load carrying capacity was observed in the condyles stored with additives, indicating maintenance of an intact cartilage matrix. However, initial testing with small sustained loads (preload) showed changes not observed at higher load levels. The changes noted at small sustained initial loads may reflect alterations in cartilage surface structure and may be an early indicator of its mechanical integrity. Chondrocyte viability and proteoglycan content, as measured by 35S incorporation and hexosamine concentration, were unchanged in comparison to fresh articular cartilage.
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This study attempted to determine the effects of interval and continuous running on factors associated with cardiovascular health. Fifty-nine untrained men and women, ages 18-32 years, were randomly assigned to one of four groups: (1) 4 mile: running continuously at 75% of maximal heart rate (approximately 500 Cal/session) (2) 2 mile: running continuously at 75% of maximal heart rate (approximately 250 Cal/session) (3) interval: running one min at 90% maximal heart rate followed by three min of walking for eight sets (approximately 500 Cal/session) (4) control: no exercise program. The training was performed three times per week for 12 weeks. Treadmill VO2 max and percent body fat by hydrostatic weighing were assessed pre- and post training. Pre and post analyses were performed on plasma for triglycerides (TG), cholesterol (Chol), and high density lipoprotein cholesterol (HDL-C). Analysis of covariance indicated that only the interval group improved more than the control in VO2 max. Percent fat decreased in all exercise groups, but no program was superior. Changes in TG, Chol, or HDL-C were not different among groups. Although men and women differed on the pretests in VO2 max, percent fat, and HDL-C, their response to the training was similar. These results indicate that interval training may benefit aerobic capacity more than continuous running in young adults who have moderately high initial fitness levels. The data also indicate that cardiovascular fitness parameters are not easily altered by short term exercise in young active men and women.
Article
The American College of Sports Medicine (ACSM) recommends the use of 40%, 60%, 80%, and 85% of maximal oxygen consumption (VO2max) as target values in developing exercise prescriptions. Further, the ACSM states that 55%, 70%, 85%, and 90% of maximal heart rate (HRmax) may be used as indices of these respective levels of % VO2max for the general population. The current study evaluated this relationship between %HRmax and %VO2max in apparently healthy, young adults. Eighty-one men and 81 women between the ages of 18 and 34 engaged in an incremental exercise test to exhaustion. Linear regressions of %HRmax and %VO2max were performed on each subject. From these regressions, target values of %HRmax were computed for each individual. Mean percentages of HRmax were 63%, 76%, 89%, and 92% at 40%, 60%, 80%, and 85% of VO2max, respectively. At all of these values of %VO2max, the values obtained for %HRmax were significantly greater (P < 0.001) than those used by the ACSM. Fitness affected these results, particularly among men. High fit men averaged 2% higher in %HRmax than low fit men at any given value of %VO2max.
Sex differences in running economy (gross oxygen cost of running, CR), maximal oxygen uptake (VO2max), anaerobic threshold (Than), percentage utilization of aerobic power (% VO2max), and Than during running were investigated. There were six men and six women aged 20–30 years with a performance time of 2 h 40 min over the marathon distance. The VO2max, Than, and CR were measured during controlled running on a treadmill at 1° and 3° gradient. From each subject's recorded time of running in the marathon, the average speed (v M) was calculated and maintained during the treadmill running for 11 min. The VO2 max was inversely related to body mass (m b), there were no sex differences, and the mean values of the reduced exponent were 0.65 for women and 0.81 for men. These results indicate that for running the unit ml·kg−0.75·min−1 is convenient when comparing individuals with different m b. The VO2max was about 10% (23 ml·kg−0.75·min−1) higher in the men than in the women. The women had on the average 10–12 ml·kg−0.75·min−1 lower VO2 than the men when running at comparable velocities. Disregarding sex, the mean value of CR was 0.211 (SEM 0.005) ml·kg−1·m−1 (resting included), and was independent of treadmill speed. No sex differences in Than expressed as % VO2max or percentage maximal heart rate were found, but Than expressed as VO2 in ml·kg−0.75·min−1 was significantly higher in the men compared to the women. The percentage utilization of f emax and concentration of blood lactate at v M was higher for the female runners. The women ran 2 days more each week than the men over the first 4 months during the half year preceding the marathon race. It was concluded that the higher VO2max and Than in the men was compensated for by more running, superior CR, and a higher exercise intensity during the race in the performance-matched female marathon runners.
Article
When maximal VO2 (VO2 MAX) is limited by O2 supply, it is generally thought that cardiac output (QT) is mostly responsible, but other O2 transport conductances [ventilation (VA); [Hb]; pulmonary (DLO2) and muscle (DMO2) diffusion capacities] may also influence VO2 MAX. A numerical analysis interactively linking the lungs, circulation and muscles was designed to compare the influences of each conductance component on VO2 MAX at three altitudes: PB = 760, 464 and 253 Torr. For any given set of conductances the analysis simultaneously solved six equations for alveolar, arterial, and venous PO2 and PcO2. The equations represent pulmonary mass balance, pulmonary diffusion, and muscle diffusion for both gases. At PB = 760, [Hb], DLO2 and DMO2 were as influential as QT in limiting VO2 MAX. With increasing altitude, the influence of QT and [Hb] fell while that of VA, DLO2 and DMO2 progressively increased until at PB = 253, VO2 MAX was independent of QT and [Hb]. Neither the fall in maximal QT nor rise in [Hb] with chronic hypoxia therefore appear to affect VO2 MAX. However, high values of ventilation, DLO2 and DMO2 appear to be advantageous for exercise at altitude.
Article
To compare the effects of three types of intensive run training on running economy (RE) during exhaustive running and to establish possible relationships with changes in ventilatory function and/or muscle fiber type distribution. Thirty-six male recreational runners were divided into three groups and assigned to either exhaustive distance training (DT), long-interval training (LIT), or short-interval training (SIT) three times 20-30 minxwk(-1) for 6 wk. VO(2 max) and RE were measured during treadmill running before and after training. Muscle fiber type distribution of the vastus lateralis muscle was established from biopsy material. VO(2max) (Lxmin(-1) increased by 5.9% (P < 0.0001), 6.0% (P < 0.0001), and 3.6% (P < 0.01) in DT, LIT, and SIT, respectively, and running speed at VO(2max) by 9% (P < 0.0001), 10% (P < 0.0001), and 4% (P < 0.05), respectively. Time-to-exhaustion at 87% of pretraining VO(2max) (mean 3.83) mxs(-1) increased by 94% in DT (P < 0.0001), 67% in LIT (P < 0.0001). Running economy improved by 3.1% in DT (P < 0.05), 3.0% in LIT (P < 0.01), and 0.9% SIT (NS): pulmonary ventilation (VE) was on average 11 Lxmin(-1) lower following training (P < 0.0001). The individual decrements in VE correlated with improvements in RE (r = 0.77; P < 0.0001) and may account for 25-70% of the decrease in aerobic demand. Muscle fiber composition, and respiratory exchange ratio, stride length, and stride frequency during running were unaltered with training. Recreational runners can improve RE and aerobic run performance by exchanging parts of their conventional aerobic distance training with intensive distance or long-interval running, whereas short-interval running is less efficient. The improvement in RE may relate to reduced ventilatory demands. Muscle fiber type distribution was unaltered with training and showed no associations with RE.
Article
The training intensity may affect the monocarboxylate transporters MCT1 and MCT4 in skeletal muscle. Therefore, 20 elite cross-country skiers (11 men and nine women) trained hard for 5 months at either moderate (MIG, 60-70% of VO2max) or high intensity (HIG, 80-90%). The lactate threshold, several performance parameters, and the blood lactate concentration (cLa) after exhausting treadmill running were also determined. Muscle biopsies taken from the vastus lateralis muscle before and after the training period were analysed for the two MCTs and for muscle fibre types and six enzymes. The concentration of MCT1 did not change for HIG (P=0.3) but fell for MIG (-12 +/- 3%, P=0.01); the training response differed between the two groups (P=0.05). The concentration of MCT4 did not change during the training period (P > 0.10). The concentration of the two MCTs did not differ between the two sexes (P=0.9). The running speed at the lactate threshold rose for HIG (+3.2 +/- 0.9%, P=0.003), while no change was seen for MIG (P=0.54); the training response differed between the two groups (P=0.04). The cLa after long-lasting exhausting treadmill running correlated with the concentration of MCT1 (rs=0.69, P=0.002), but not with that of MCT4 (rs=0.2, P=0.2). There were no other significant correlations between the concentrations of the two MCTs and the performance parameters, muscle fibre types, or enzymes (r < or = 0.36, P > 0.10). Thus, the training response differed between MIG and HIG both in terms of performance and of the effect on MCT1. Training at high intensity may be more effective for cross-country skiers. Finally, MCT1 may be important for releasing lactate to the blood during long-lasting exercise.
Article
The aim of the present study was to study the effects of aerobic training on performance during soccer match and soccer specific tests. Nineteen male elite junior soccer players, age 18.1 +/- 0.8 yr, randomly assigned to the training group (N = 9) and the control group (N = 10) participated in the study. The specific aerobic training consisted of interval training, four times 4 min at 90-95% of maximal heart rate, with a 3-min jog in between, twice per week for 8 wk. Players were monitored by video during two matches, one before and one after training. In the training group: a) maximal oxygen uptake (VO2max) increased from 58.1 +/- 4.5 mL x kg(-1) x min(-1) to 64.3 +/- 3.9 mL x kg(-1) x min(-1) (P < 0.01); b) lactate threshold improved from 47.8 +/- 5.3 mL x kg(-1) x min(-1) to 55.4 +/- 4.1 mL x kg(-1) x min(-1) (P < 0.01); c) running economy was also improved by 6.7% (P < 0.05); d) distance covered during a match increased by 20% in the training group (P < 0.01); e) number of sprints increased by 100% (P < 0.01); f) number of involvements with the ball increased by 24% (P < 0.05); g) the average work intensity during a soccer match, measured as percent of maximal heart rate, was enhanced from 82.7 +/- 3.4% to 85.6 +/- 3.1% (P < 0.05); and h) no changes were found in maximal vertical jumping height, strength, speed, kicking velocity, kicking precision, or quality of passes after the training period. The control group showed no changes in any of the tested parameters. Enhanced aerobic endurance in soccer players improved soccer performance by increasing the distance covered, enhancing work intensity, and increasing the number of sprints and involvements with the ball during a match.
Article
The aim of this experiment was to examine the effects of maximal strength training with emphasis on neural adaptations on strength- and endurance-performance for endurance trained athletes. Nineteen male cross-country skiers about 19.7 +/- 4.0 years of age and a maximal oxygen uptake (VO(2 max)) of 69.4 +/- 2.2 mL x kg(-1) x min(-1) were randomly assigned to a training group (n = 9) or a control group (n = 10). Strength training was performed, three times a week for 8 weeks, using a cable pulley simulating the movements in double poling in cross-country skiing, and consisted of three sets of six repetitions at a workload of 85% of one repetition maximum emphasizing maximal mobilization of force in the concentric movement. One repetition maximum improved significantly from 40.3 +/- 4.5 to 44.3 +/- 4.9 kg. Time to peak force (TPF) was reduced by 50 and 60% on two different submaximal workloads. Endurance performance measured as time to exhaustion (TTE) on a double poling ski ergometer at maximum aerobic velocity, improved from 6.49 to 10.18 min; 20.5% over the control group. Work economy changed significantly from 1.02 +/- 0.14 to 0.74 +/- 0.10 mL x kg(-0.67) x min(-1). Maximal strength training with emphasis on neural adaptations improves strength, particularly rate of force development, and improves aerobic endurance performance by improved work economy.
Article
Increased aerobic exercise capacity appears to reduce both all-cause mortality and cardiovascular disease mortality. Physical exercise to improve peak oxygen uptake (VO2peak) is thus strongly recommended, however evidence regarding the most efficient training intensity for patients with coronary artery disease (CAD) is still lacking. The purpose of this randomized study was therefore to assess the effects of high intensity aerobic interval exercise compared to moderate intensity exercise, representing the same total training load, for increasing VO2peak in stable CAD-patients. Twenty-one stable CAD-patients were randomized to supervised treadmill walking at either high intensity (80-90% of VO2peak) or moderate intensity (50-60% of VO2peak) three times a week for 10 weeks. After training VO2peak increased by 17.9% (P=0.012) in the high intensity group and 7.9% (P=0.038) in the moderate intensity group. The training-induced adaptation was significantly higher in the high intensity group (P=0.011). High intensity aerobic interval exercise is superior to moderate exercise for increasing VO2peak in stable CAD-patients. As VO2peak seems to reflect a continuum between health and cardiovascular disease and death, the present data may be useful in designing effective training programmes for improved health in the future.