Article

HIIT in the Real World: Outcomes from a 12-Month Intervention in Overweight Adults

April 2018
Medicine and Science in Sports and Exercise 50(9):1

DOI:10.1249/MSS.0000000000001642

Authors:

Melyssa Roy

University of Otago

Sheila Williams

University of Otago

Rachel C Brown

University of Otago

Kim Meredith-Jones

University of Otago

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Purpose: Although high-intensity interval training (HIIT) and moderate-intensity continuous exercise have comparable health outcomes in the laboratory setting, effectiveness studies in real-world environments are lacking. The aim of this study was to determine the effectiveness of an unsupervised HIIT programme in overweight/obese adults over 12 months. Methods: 250 overweight/obese adults could choose HIIT or current exercise guidelines of 30 minutes/day moderate-intensity exercise. HIIT participants received a single training session and were advised to independently perform HIIT 3x/week utilizing a variety of protocols. Mixed models, with a random effect for participant, compared differences in weight, body composition, blood pressure, aerobic fitness, physical activity and blood indices at 12 months, adjusting for relevant baseline variables. Results: Forty-two percent (n=104) of eligible participants chose HIIT in preference to current guidelines. At 12 months, there were no differences between exercise groups in weight (adjusted difference HIIT vs conventional; 95% CI: -0.44kg; -2.5, 1.6) or visceral fat (-103cm; -256, 49), although HIIT participants reported greater enjoyment of physical activity (p=0.01). Evidence of adherence to ≥2 sessions/week of unsupervised HIIT (from heart rate monitoring) declined from 60.8% at baseline to 19.6% by 12 months. Participants remaining adherent to HIIT over 12 months (23%) were more likely to be male (67% vs 36%, p=0.03), with greater reductions in weight (-2.7kg; -5.2 -0.2) and visceral fat (-292cm; -483, -101) than non-adherent participants. Conclusions: HIIT was well-accepted by overweight adults and opting for HIIT as an alternative to standard exercise recommendations led to no difference in health outcomes after 12 months. While regular participation in unsupervised HIIT declined rapidly, those apparently adherent to regular HIIT demonstrated beneficial weight loss and visceral fat reduction. Trial registration: Australian New Zealand Clinical Trials Registry (ACTRN12615000010594) Retrospectively registered.

Effectiveness of high-intensity interval training and moderate-intensity continuous training on cardiometabolic health in university labourers

Article

Full-text available

Jan 2024

Background: The prevalence of obesity continues to drive the growth of chronic, non-communicable diseases in sub-Saharan African countries. Little evidence is available to prevent the spread of chronic diseases in vulnerable African communities and amongst workers living in these settings. This study aimed to compare and evaluate the effectiveness of a 12-week high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on cardiometabolic health in a cohort of African workers. Methods: Forty-three Black South African university professional workers employed at the University of the Witwatersrand were randomized into 3 groups: HIIT (n = 17), a MICT (n = 15) and a control group (n = 11). The HIIT performed progressive supervised exercise on a cycle ergometer, the MICT performed continuous aerobic activity and the control group maintained their usual routines. Changes in body composition, blood glucose, blood pressure and VO2max outcomes were measured at baseline and at 3-month follow-up. Results: Compared to controls both HIIT and MICT significantly reduced waist circumference (−5.3 and −4.0 cm), BMI (−2.4 and −1.9), and blood pressure (systolic & diastolic - moderate to large effects) (p ♯αμπ;λτ; 0.05). Similarly, blood glucose levels dropped in both intervention groups (−1.9 and −2.0 mmol/L−1) (p ♯αμπ;λτ; 0.05). Notably, both interventions significantly improved VO2max (+7.5 and +7.0 mL.kg ⁻¹ .min ⁻¹ ) (p ♯αμπ;λτ; 0.05). Conclusions: These findings suggest both HIIT and MICT effectively improve key health markers. In the context of a growing chronic diseases crisis, our study provides important formative data for developing feasible workplace interventions to improve health outcomes.

Adherence to unsupervised exercise in sedentary individuals: A randomised feasibility trial of two mobile health interventions

Article

Full-text available

Jun 2023

Introduction Adherence to unsupervised exercise is poor, yet unsupervised exercise interventions are utilised in most healthcare settings. Thus, investigating novel ways to enhance adherence to unsupervised exercise is essential. This study aimed to examine the feasibility of two mobile health (mHealth) technology–supported exercise and physical activity (PA) interventions to increase adherence to unsupervised exercise. Methods Eighty-six participants were randomised to online resources ( n = 44, females n = 29) or MOTIVATE ( n = 42, females n = 28). The online resources group had access to booklets and videos to assist in performing a progressive exercise programme. MOTIVATE participants received exercise counselling sessions supported via mHealth biometrics which allowed instant participant feedback on exercise intensity, and communication with an exercise specialist. Heart rate (HR) monitoring, survey-reported exercise behaviour and accelerometer-derived PA were used to quantify adherence. Remote measurement techniques were used to assess anthropometrics, blood pressure, HbA 1c and lipid profiles. Results HR–derived adherence rates were 22 ± 34% and 113 ± 68% in the online resources and MOTIVATE groups, respectively. Self-reported exercise behaviour demonstrated moderate (Cohen's d = 0.63, CI = 0.27 to 0.99) and large effects (Cohen's d = 0.88, CI = 0.49 to 1.26) in favour of online resources and MOTIVATE groups, respectively. When dropouts were included, 84% of remotely gathered data were available, with dropouts removed data availability was 94%. Conclusion Data suggest both interventions have a positive impact on adherence to unsupervised exercise but MOTIVATE enables participants to meet recommended exercise guidelines. Nevertheless, to maximise adherence to unsupervised exercise, future appropriately powered trials should explore the effectiveness of the MOTIVATE intervention.

Home-Based HIIT and Traditional MICT Prescriptions Improve Cardiorespiratory Fitness to a Similar Extent Within an Exercise Referral Scheme for At-Risk Individuals

Article

Full-text available

Nov 2021

Exercise referral schemes (ERS) are used to promote physical activity within primary care. Traditionally, ERS are conducted in a gym or leisure-center setting, with exercise prescriptions based on moderate-intensity continuous training (MICT). Home-based high-intensity interval training (Home-HIIT) has the potential to reduce perceived barriers to exercise, including lack of time and access to facilities, compared to traditional MICT prescription used with ERS and improve health related outcomes. We hypothesized that Home-HIIT would mediate greater improvement in cardiorespiratory fitness (CRF) by virtue of greater adherence and compliance to the exercise prescription, compared to MICT. Methods: Patients enrolled on an ERS (Liverpool, United Kingdom) were recruited for a pragmatic trial. Participants self-selected either 12 weeks of MICT (45–135 min/week at 50–70% HRmax) or Home-HIIT (4–9 min × 1 min intervals at ≥80% of HRmax, interspersed with 1 min rest). The primary outcome was the change in CRF (VO2peak) at post-intervention (12 weeks) and follow-up (3-month post intervention), using intention-to-treat analysis. Results: 154 participants (age 48 ± 10y; BMI 30.5 ± 6.1 kg/m²) were recruited between October 2017 and March 2019, 87 (56%) participants chose Home-HIIT and 67 (44%) MICT. VO2peak increased post-intervention in both groups (MICT 3.9 ± 6.0 ml.kg–1.min–1, Home-HIIT 2.8 ± 4.5 ml.kg–1.min–1, P < 0.001), and was maintained at follow-up (P < 0.001). Fat mass was only reduced post MICT (MICT −1.5 ± 6.3 kg, P < 0.05, Home-HIIT −0.2 ± 2.0 kg, P = 1.00), but the reduction was not maintained at follow-up (MICT −0.6 ± 5.1 kg, Home-HIIT 0.0 ± 2.2 kg, P > 0.05). Adherence to the prescribed programs was similar (MICT 48 ± 35%, Home-HIIT 39 ± 36%, P = 0.77). Conclusion: This is the first study to evaluate the use of Home-HIIT for individuals in a primary care setting. Contrary to our hypothesis, adherence to both exercise prescriptions was poor, and CRF improved to a similar extent in both groups with improvements maintained at 3-month follow-up. We provide evidence that, although not superior, Home-HIIT could be an effective and popular additional exercise choice for patients within primary care based ERS. Clinical Trial Registration: [ClinicalTrials.gov], identifier [NCT04553614].

A Group-Based 8-Week Functional Interval-Type Outdoor Training Program Improves Physical Performance in Recreationally Active Adults

Article

Full-text available

Mar 2021

Even though physical activity is an important aspect of health, lack of time or motivation impede people from working out regularly. One type of training program that is both efficient and motivating is functional interval-type outdoor training. To evaluate this, our study had 81 participants complete a battery of physical performance tests (incremental treadmill test, core stability test and functional fitness test) before and after an 8-week outdoor interval-type training intervention. Training procedures included multimodal and high-intensity exercises performed in consistent, small groups. Results showed that the interval training program produced significant increases in the intervention group (n = 43) in functional and strength exercises (p < 0.001; squat (+27%), burpee (+24%), bridge (+39%), push-up (+34%), sit-up (+25%), high knees (+25%), row (+19%), effect sizes 0.4–0.11) for almost all parameters in comparison to a non-intervention control population (n = 38). Interestingly, trunk stability increased significantly (p < 0.001; flexion (+86%), extension (+43%), lateral left (+39%), lateral right (+32%), effect sizes 0.3–0.15) even though it was not explicitly trained; this was rather a secondary outcome of the functional exercises. Drop-out rates (Intervention group: 27%) suggest that this form of training seems to improve adherence to exercise and may help participants to stay committed to regular, intense activity. By simultaneously triggering adaptations in functional fitness, endurance and whole-body movements, this program can be used by people at different training levels.

Effect of High-Intensity Interval, Moderate-Intensity Continuous, and Self-Selected Intensity Training on Health and Affective Responses

Article

Jan 2023
RES Q EXERCISE SPORT

Purpose: To compare the effects of 12-week high-intensity interval (HIIT), moderate-intensity continuous (MICT), and self-selected intensity training (SSIT) on health outcomes and affective responses. Methods: Seventy-three overweight/obese inactive adults (62% woman; age, 31.4 ± 7.2 years; height, 1.66 ± 0.09 cm; Body mass index, 28.9 ± 2.7 kg.m−2) who were randomized into HIIT (n = 23), MICT (n = 24) and SSIT (n = 26) groups. The training was conducted three times per week in an outdoor environment, with 4 weeks under direct supervision and 8 weeks with semi-supervision. Cardiorespiratory fitness, body composition, and metabolic profile were evaluated at baseline and at the end of the 4th and 12th weeks. Core affect was measured during all training sessions. Results: Peak oxygen uptake improved in all groups after 4 and 12 weeks compared with baseline. Only the SSIT had reductions in body fat throughout the intervention. No improvements were observed in the metabolic profile across all groups. SSIT was perceived as more pleasurable than HIIT; however, there were no differences in affective responses between SSIT and MICT. Affective responses in-task (e.g. negative and positive peak, rate of change and affect at the end of the exercise session) predicted the HIIT and SSIT exercises attendance rate. Conclusion: Regardless of the exercise training protocol, overweight/obese inactive adults improved health outcomes, which suggests the prescribing HIIT, MICT, and SSIT in outdoor environments. SSIT should be considered in order to optimize the pleasure during training sessions. Affective response more positive in-task of the HIIT and SSIT is associated with greater attendance rate in these exercise protocols.

Psychological Adaptations to High-Intensity Interval Training in Overweight and Obese Adults: A Topical Review

Article

Full-text available

Apr 2022

Regular exercise has been reported as a fundamental piece of the management and treatment puzzle of obesity, playing a vital role in numerous psychological indicators. However, it is unclear whether high-intensity interval training (HIIT) can improve critical psychological health markers such as adherence, exercise enjoyment, affective responses, health-related quality of life, anxiety, and depression in overweight and obese adults. The purpose of this topical review was to catalogue studies investigating the psychological responses to HIIT in order to identify what psychological outcomes have been assessed, the research methods used, and the results. The inclusion/exclusion criteria were met by 25 published articles investigating either a traditional, single-component (84%) or a hybrid-type, multi-component (16%) HIIT protocol and involving 930 participants with overweight/obesity. The present topical review on HIIT-induced psychological adaptations shows that this popular exercise mode, but also demanding for the masses, can meaningfully increase the vast majority of the selected mental health-related indices. These improvements seem to be equal if not greater than those observed for moderate-intensity continuous training in overweight and obese adults. However, further research is needed in this area, focusing on the potential mechanisms behind positive alterations in various psychological health parameters through larger samples and high-quality randomized controlled trials.

High-Intensity Interval Training in Metabolic Diseases: Physiological Adaptations

Article

Full-text available

Sep 2021

HIIT is an effective exercise mode inducing meaningful benefits on physical fitness, metabolic health, and cardiovascular function. This training approach requires adults with metabolic diseases to engage in physically and mentally demanding conditions with respect to the exercise intensity commonly used in other modalities. However, emerging research reveals that incorporating HIIT as part of a comprehensive exercise program for individuals with impaired metabolic health could be a pleasurable and feasible training option aimed at improving health and fitness.

Maintenance of time-restricted eating and high-intensity interval training in women with overweight/obesity 2 years after a randomized controlled trial

Article

Full-text available

Apr 2025

Time-restricted eating (TRE) and high-intensity interval training (HIIT) improve cardiometabolic health in individuals with overweight/obesity, with high adherence rates in supervised settings. Long-term maintenance of TRE and HIIT in real-world settings is unknown. In our previous TREHIIT trial, 131 women (body mass index (BMI) ≥ 27 kg/m²) were randomized to 7 weeks of TRE (eating window 10-h/day), HIIT (3 sessions/week), a combination (TREHIIT), or no intervention (CON). We investigated self-reported continuation of TRE and/or HIIT after 2 years. Fifty-nine participants (39.0 years (standard deviation (SD) 6.1), BMI 30.7 kg/m² (SD 4.2)) attended the follow-up. Of those who completed the 7-week TRE or HIIT intervention, 46% maintained TRE and 45% continued HIIT for 2 years. There were no statistically significant (at p < .01) between-group differences in cardiometabolic outcomes, but non-significant lower body mass in HIIT (-4.2 kg, 95% confidence interval (CI), -7.7 to -0.7, p = .019) and visceral fat in TREHIIT (-18 cm², CI, -33 to -4, p = .015) versus CON. After 2 years, HIIT and TREHIIT had ~ 4 kg lower fat mass and ~ 20 cm² lower visceral fat (both p < .001) compared with baseline. A short-term TRE and HIIT intervention may promote long-term lifestyle changes and health benefits. Future studies should collect objective adherence data to understand long-term maintenance of TRE and HIIT.

Comparing the Effects of Two Workout Protocols (HIIT vs. MICT) over Body Composition and Metabolic Markers on Early Adolescents with Obesity.

Article

Full-text available

Jan 2025

Introduction: Obesity in adolescents increases the risk of chronic diseases. Studies have shown that increasing physical activity improves metabolic health. However, there is a divergence regarding the effectiveness of different types of physical activity programs in adolescents. Objective: To determine the effects of two physical activity programs on early adolescents with obesity, and to compare their benefits on body composition and metabolic markers. Methodology: 35 adolescents diagnosed with obesity from a public school were selected and randomized in two groups. The HIIT group (n = 18) performed 1 min of intense exercise at 80-100 % of the maximum heart rate (HRmax) and rested 2 for a min, repeating this cycle 10 times; the MICT group (n = 17) performed 30 min of continuous exercise at 55-69% of HRmax. Both exercise programs were performed on a static bike, 3 times per week, for 12 weeks. All the participants had nutritional counseling weekly. Results: We detected a statistically significant increase in the lean mass (p = 0.008 and p = 0.002) and a decrease in triglyceride levels (p = 0.080 and p <0.001), for the MICT and the HIIT groups, respectively. Conclusion: Both exercise programs in conjunction with nutritional counseling, lead to a significant increase in lean mass and a decrease in triglyceride levels. MICT had a greater impact in decreasing fat mass, and both had a similar impact in reducing triglycerides levels.

Wysiłek fizyczny jako terapia wspomagająca w leczeniu schizofrenii

Article

Full-text available

Feb 2019

Celem artykułu było opisanie wpływu wysiłku fizycznego na funkcjonowanie osób cierpiących na choroby psychiczne. Poddano krytycznemu przeglądowi literaturę dotyczącą tej kwestii oraz usystematyzowano aktualny stan wiedzy. Efektem pracy grona ekspertów Europejskiego Towarzystwa Psychiatrycznego było wydanie w jesienią 2018 roku zaleceń dotyczących stosowania wysiłku fizycznego w leczeniu pacjentów z chorobami psychicznymi. Chorzy na schizofrenię żyją o około 10-20 lat krócej od populacji ogólnej, przy czym zapadalność na choroby metaboliczne jest około 4–krotnie, a na choroby sercowo naczyniowe - 2-3 krotnie większa. Tłumaczy się to niską aktywnością fizyczną, złą dietą, brakiem dbałości o właściwe leczenie schorzeń somatycznych, ale także efektami ubocznymi leków przeciwpsychotycznych. Dobrze udokumentowany jest fakt, że regularny wysiłek fizyczny wraz z oddziaływaniami psychoedukacyjnymi i dietą może prowadzić do poprawy parametrów zespołu metabolicznego oraz wydolności sercowo - naczyniowej. Należy zaznaczyć, że trening o umiarkowanej i wysokiej intensywności jest atrakcyjną formą skojarzonego leczenia, dostępnego praktycznie dla każdego pacjenta, ze względu na szeroki wachlarz możliwości dostosowania treningu do wieku, wydolności i upodobań chorego. Aktywność fizyczna ma udowodniony pozytywny wpływ na funkcje poznawcze oraz pomaga w redukcji objawów w schizofrenii poprzez wpływ na hipokamp. Oczekuje się, że wyniki badań oraz wysokiej jakości badania kliniczne pomogą w przyszłości w stworzeniu praktycznych zaleceń dotyczących programu treningowego o optymalnej długości i formie ćwiczeń aerobowych dla pacjentów cierpiących na schizofrenię. Niezbędne jest również prowadzenie psychoedukacji w kierunku podnoszenia świadomości pacjentów, że wysiłek fizyczny jest skuteczną formą wspomagania leczenia schizofrenii oraz poprawy jakości i długości życia.

A free-living, walking-based, exercise programme, with exercise timed relative to breakfast, to improve metabolic health in people living with overweight and obesity: A feasibility study

Article

Full-text available

Nov 2024
PLOS ONE

Optimising the timing of food intake relative to exercise may maximise the effectiveness of free-living exercise programmes on improvements in glycaemic control and cardio-metabolic health. This study aimed to assess the feasibility of a free-living, walking-based exercise programme and determine whether undertaking each exercise session before or after breakfast would most benefit longer-term metabolic health. Thirty-four people living with obesity (43±12 y, BMI 35.1±5.1 kg.m⁻²) undertook a 12-week walking-based programme, consisting of two continuous (30–60 min at 50% HRmax) and two interval exercise sessions per week (30–60 min, alternating 3 min at 85% HRmax and 3 min at 50% HRmax). Participants were allocated to exercise before (FASTED) or after (FED) breakfast (n = 17 per group). Feasibility (acceptability, adherence and compliance) to the exercise intervention were assessed, as well as changes in anthropometric variables, 24-hour continuous glucose monitoring, serum biochemistry including HbA1c, lipid profile and liver transaminases. Exercise adherence (FASTED: 93±4%, FED: 95±5%) and compliance (FASTED: 85±10%, FED: 88±10%) was high in both groups, and participants described exercise monitoring, programme structure and support as facilitators to this. Body mass, BMI, waist-to-hip ratio and HbA1c decreased similarly between groups (all P<0.01). However, serum ALT concentrations decreased after FASTED (-16± -14%; P = 0.001), but not FED training (-2 ± -4%; P = 0.720). We demonstrate that a free-living walking-based exercise programme, with exercise timed relative to breakfast can achieve high adherence and compliance and improve some anthropometric variables and HbA1c. Whether FASTED exercise can elicit greater improvements in liver health requires further investigation.

Adherence Patterns and Health Outcomes in Spanish Young Women Participating in a Virtual-Guided HIIT Program: Insights from the Randomized Controlled WISE Trial

Article

Full-text available

Oct 2024

Background/Objectives. A notable decline in physical activity from late adolescence to early adulthood affects young women especially. This study aimed to investigate adherence to an unsupervised virtual-guided high-intensity interval training (HIIT) exercise program among young women in Spain. Methods. A total of 106 participants were recruited and randomized to the Women’s Involvement in Steady Exercise (WISE) trial exercise program, administered remotely via a mobile app, and a control group. The primary outcome was adherence measured through daily steps. Secondary variables were patient-reported outcomes of physical activity, quality of sleep, and quality of life, assessed with the International Physical Activity Questionnaire (IPAQ), the Pittsburgh Sleep Quality Index (PSQI), and the Health Lifestyle and Personal Control Questionnaire (HLPCQ), respectively. The assessments were performed over 6 months, before the intervention (T0), at the halfway of the program (T1), and at the end (T2). Results. Daily steps revealed a decrease from baseline to final assessment in both groups. Secondary outcomes indicated a shift in physical activity levels, showing a transition from low to moderate and high activity perception. While sleep quality deteriorated post-intervention, quality of life showed no changes. Conclusions. The WISE trial highlights the potential and challenges of an unsupervised virtual-guided HIIT program for young women. While an improvement in physical activity levels was noticed, it also led to a decrease in daily steps and poorer sleep quality. These findings suggest a complex relationship between exercise and lifestyle factors, which could potentially have the greatest impact.

Effects of low-volume functional and running high-intensity interval training on physical fitness in young adults with overweight/obesity

Article

Full-text available

Jan 2024

Objectives: This study examined and compared the effects of functional and running high-intensity interval training (HIIT) on body composition, cardiorespiratory fitness, and muscular fitness of young adults with overweight or obesity. Methods: Forty-five participants (22.1 ± 2.1 years, BMI = 25.2 ± 1.0 kg/m²) were assigned to functional HIIT (HIIT-F; n = 15), running HIIT (HIIT-R; n = 15), or non-training control group (CON; n = 15). Participants in HIIT-F and HIIT-R performed functional exercise based-HIIT (four sets of all-out whole-body exercises including jumping jacks, squats, twist jumps and mountain climbers, et al.) and running HIIT (four sets of running on a treadmill) for 12 weeks, respectively. Body composition, muscular fitness, and cardiorespiratory fitness were assessed pre and post intervention. Results: Both HIIT-F and HIIT-R significantly improved the body composition and cardiorespiratory fitness, with HIIT-F induced greater improvements in lean mass (+1.623 vs. −1.034 kg, p < 0.001), back strength (+6.007 vs. +3.333 kg, p < 0.01), and push-ups (+5.692 vs. 1.923 reps, p < 0.001) than that in HIIT-R. HIIT-R reduced more visceral fat area (VFA) (−11.416 vs. −4.338 cm², p = 0.052) and induced similar improvement in cardiorespiratory fitness (VO2max, +2.192 vs. +2.885 mL/kg/min, p = 0.792) with HIIT-F. Conclusion: Twelve weeks of HIIT-R or HIIT-F improved physical fitness among young adults with overweight or obesity. Despite the similar impact on cardiorespiratory fitness, HIIT-F generates a better positive effect on muscular fitness relative to HIIT-R, which could be partly explained by the greater increase in lean mass after HIIT-F intervention.

High intensity interval training on physical fitness

Article

Full-text available

Dec 2023

physical performance, and sports. This article examines the research on high intensity interval training. This article aims to determine the effectiveness of high-intensity interval training on fitness and endurance. Data sources were taken from Scholar, Scimago Jr., Wiley Online Library, Springer. Search data ranges from 2015 to 2023. The method of implementing activities uses the literature review method. In this article, it is recommended that high intensity interval training should be done regularly with the right intensity and sufficient duration to achieve optimal results. The results of the review concluded that high intensity interval training can be done outside or inside the house which is suitable for athletes and non-athletes because it can increase muscle strength, reduce high blood pressure, improve cardiorespiratory fitness, burn fat, and help cure diabetes. In conclusion, high intensity interval training has an influence on changes in improving performance, health, and endurance. This strength training can further be developed or tested with various variables, subject characteristics, and a larger population. HIIT exercise can greatly increase physical performance. Optimal physical ability is intended to increase the body's metabolic system, cardiovascular fitness, and endurance, as well as influence health levels. HIIT is a quick and effective exercise that can be done both indoors and outdoors.Key words: high intensity interval training, physical fitness, endurance

A Systematic Review of the Influence of High-Intensity Interval Training on Body Composition and Synthesizing Evidence from Scientific Literature

Article

Full-text available

May 2023

INTRODUCTION AND OBJECTIVE High-intensity interval training (HIIT) involves performing a series of intense exercises interspersed with periods of passive or active rest. HIIT provides changes in body composition and physical fitness. The aim of this study is to determine the impact of HIIT on changes in body composition and compare the results of HIIT with moderate-intensity continuous training (MICT) and resistance training (RT). REVIEW METHODS The PubMed and Google Scholar databases were searched for studies examining the impact of HIIT on changes in body composition. Articles published up to 31.03.2023 were included, with a particular focus on the most recent publications. STATE OF KNOWLEDGE The classification of HIIT considers the intensity, duration and number of bouts during training session, as well as the length of the intervention period. Body composition describes qualitive and quantitative elements in the human body. Improving body composition benefits health and enables better training results. HIIT promotes weight loss, reduces BMI and decreases the content of adipose tissue, including visceral fat. HIIT is equally or more effective than MICT in burning fat tissue. Resistance exercises added to HIIT protocols have a favorable effect on changes in body composition. SUMMARY The assessment of HIIT effects on changes in body composition is complicated due to various interpretations of its definition. Further analyses are needed to systematize knowledge of the benefits of different HIIT protocols. Research optimizing them for reducing adipose tissue based on age, gender, body mass and presence of metabolic disorders are necessary.

The Effects of Qigong Intervention Based On Internet On Quality of Life And Physical Fitness In Chinese Postoperative Breast Cancer Patients: A Protocol of Randomized Controlled Trial

Preprint

Full-text available

Jan 2020

Background: The purpose of this study is to verify the improvement of remote qigong intervention on the quality of life and physical fitness of breast cancer patients after surgery by means of a randomized controlled trial, and to compare it with the conventional exercise combination of aerobic exercise and resistance training. Methods/design: The research approach applied in this study is a randomized controlled trial. After completing the baseline questionnaire and physical fitness test, participants were randomly assigned to either the qigong group or the combined exercise rehabilitation group. Patients in the qigong group performed Qigong-Baduanjin twice a week for 30 minutes each time under remote guidance and practiced Baduanjin by themselves at other times. Patients in the combined exercise rehabilitation group were given resistance training twice a week for 30 minutes under remote guidance, and walking the rest of the time. At the end of the 12-week intervention, outcomes testing and data collection were carried out. The primary outcomes are quality of life, measured using the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), and the Functional Assessment of Cancer Therapy-Breast (FATC-B). The secondary outcomes include cardiopulmonary endurance, upper limb strength, lower limb strength and skinfold thickness. Discussion: The importance of postoperative exercise rehabilitation for breast cancer has been gradually accepted by more and more doctors and patients, but further research and development of simple and practical means of exercise rehabilitation are necessary. Remote qigong intervention for breast cancer patients via the Internet will be a great alternative. Trial registration: chictr, ChiCTR1900027989 December 7, 2,http://www.chictr.org.cn/index.aspx

The effects of Qigong intervention based on internet on quality of life and physical fitness in Chinese postoperative breast cancer patients: a protocol of randomized controlled trial

Preprint

Full-text available

Jan 2020

The Association Between Objectively-Measured Physical Activity and Cognitive Functioning in Middle-Aged and Older People Living with HIV

Article

Full-text available

Sep 2022
AIDS BEHAV

Middle-aged and older people living with HIV (PWH) are at higher risk for cognitive impairment and engage in lower levels of physical activity (PA) than seronegative counterparts. Research examining the association between objectively-measured PA and cognitive function in this population is scarce. This cross-sectional study examined the association between accelerometry-measured PA and cognitive functioning among 75 PWH (mean age 55.63). Light PA was the PA variable with the most consistent associations with cognition, with more minutes per week of light PA (performed in bouts of ≥ 10 min) being associated with better executive function, working memory/attention, and speed of processing performance, adjusted for age and current CD4 count. Findings suggest that although middle-aged and older PWH engage in more light than moderate-to-vigorous PA, light PA may be beneficial to cognition. Longitudinal studies are needed to understand PA dose–response associations with cognitive trajectories, cognitive domain specificity of PA effects, and underlying neural mechanisms of PA.

Increased Lean Body Mass After Bodyweight- Based High Intensity Interval Training in Overweight and Obese Men

Article

Apr 2022
RES Q EXERCISE SPORT

Purpose: The effects of 8 weeks of bodyweight exercise-based, high-intensity interval training (BWHIIT) on body composition and blood-based markers of metabolic health were investigated in overweight and obese, sedentary young men. Methods: In a parallel group, PRE-POST design, n = 30 men (age, 25.7 ± 4.3 y; body mass index, 27.7 ± 2.1 kg m−2; 26.1 ± 5.2% body fat) were randomized to BWHIIT (n = 20) or a control group (CON; n = 10). BWHIIT consisted of supervised, group-based training sessions (~30 minutes) performed 3 times weekly. Each session consisted of 6 high-intensity bodyweight-based exercises, with each exercise being performed for 4 minutes in the manner of 8 sets of 20 seconds of exercise, 10 seconds of rest. Prior to commencing training (PRE), and 36 h after the final training session (POST), an overnight fasted blood sample was drawn, and body composition was assessed by dual-energy X-ray absorptiometry. Eighteen participants completed the intervention (CON, n = 9; BWHIIT, n = 9). Results: Lean body mass (LBM) was increased at POST in BWHIIT compared to CON (P = .011, η2p = .359), with the mean (95% confidence limits) increase in LBM from PRE to POST within BWHIIT being 1.23 (0.55, 1.92) kg. Body mass and fat mass were unchanged in both groups from PRE to POST. BWHIIT had no effect on serum concentrations of total cholesterol, HDL-C, LDL-C, triglycerides, NEFA, hsCRP, or glucose. Conclusion: Eight weeks of bodyweight exercise-based high intensity interval training by overweight and obese sedentary young men increased LBM by ~2%, but fat mass and blood-based markers of metabolic health were unchanged.

Effects of high intensity interval training on sustained reduction in cardiometabolic risk associated with overweight/obesity. A randomized trial

Article

Full-text available

Mar 2022
J EXERC SCI FIT

Background Considering the potential greater cardiocirculatory effects of high intensity interval training (HIIT), we hypothesized that a 2-month supervised a high volume short interval HIIT would induce greater improvements in CRF and cardiometabolic risk and increase long-term maintenance compared to isocaloric moderate intensity continuous training (MICT) in overweight/obesity. Methods Sixty (19 females) subjects with overweight/obesity were randomized to three training programs (3 times/week for 2 months): MICT (45 min, 50% peak power output-PPO), HIIT (22 × 1-min cycling at 100% PPO/1-min passive recovery) and HIIT-RM (RM: recovery modulation, i.e. subjects adjusted passive recovery duration between 30s-2 min). After the intervention, participants no longer benefited from supervised physical activity and were instructed to maintain the same exercise modalities on their own. We assessed anthropometrics, body composition, CRF, fat oxidation, lipid profile, glycemic balance, low-grade inflammation, vascular function, spontaneous physical activity and motivation for eating at three time points: baseline (T0), 4 days after the end of the 2-month supervised training program (T2) and 4 months after the end of the training program (T6). Results HIIT/HIIT-RM induced greater improvement in VO2peak (between +14% and +17%), power output at ventilatory thresholds and at maximal fat oxidation rate (+25%) and waist circumference (−1.53 cm) compared to MICT and tended to decrease insulin resistance. During the four-month follow-up period during which exercise in autonomy was prescribed, HIIT induced a greater preservation of CRF, decreases in total and abdominal fat masses and total cholesterol/HDL. Conclusion We have shown greater short-term benefits induced by a high volume short interval (1 min) HIIT on cardiorespiratory fitness and cardiometabolic risk over an isocaloric moderate intensity continuous exercise in persons with overweight/obesity. We also showed greater long-term effects (i.e. after 4 months) of this exercise modality on the maintenance of CRF, decreases in total and abdominal fat masses and total cholesterol/HDL.

A Real-World High-Intensity Interval Training Protocol for Cardiorespiratory Fitness Improvement

Article

Full-text available

Feb 2022
JoVE

High-Intensity Interval Training (HIIT) has emerged as an interesting time-efficient approach to increase exercise adherence and improve health. However, few studies have tested the efficiency of HIIT protocols in a "real world" setting, e.g., HIIT protocols designed for outdoor spaces without specialized equipment. This study presents a "real world" training protocol, named "beep training", and compares the efficiency of a HIIT regiment versus a traditional long-duration Moderate-Intensity Continuous Training (MICT) regiment using this beep training protocol on VO2 max of overweight untrained men. Twenty-two subjects performed outdoor running with MICT (n = 11) or HIIT (n = 11). Cardiorespiratory fitness was assessed before and after training protocols using a metabolic analyzer. Both training protocols were performed 3 days a week for 8 weeks using the Beep Test results. The MICT group performed the exercise program at 60%-75% of the maximum speed of the 20 m shuttle test (Vmax) and with a progression of the distance of 3,500-5,000 m. The HIIT group performed the interval exercise with 7-10 bouts of 200 m at 85%-100% of the maximum speed of the 20 m shuttle test (Vmax), interspersed with 1 min of passive recovery. Although the HIIT group presented a significantly lower training volume than the MICT group (p < 0.05) after 8 weeks of beep training, HIIT was superior to MICT in improving VO2 max (MICT: ~4.1%; HIIT: ~7.3%; p < 0.05). The "real world" HIIT regiment based on beep training protocol is a time-efficient, low-cost, and easy-to-implement protocol for overweight untrained men.

Effect of Real-Time Online High-Intensity Interval Training on Physiological and Physical Parameters for Abdominally Obese Women: A Randomized Pilot Study

Article

Full-text available

Dec 2021

Ah-Hyun Hyun

Purpose: This study aimed to investigate the effects of online high-intensity interval training (HIIT) in abdominally obese women experiencing health complications due to COVID-19. Methods: Sixteen participants were enrolled and divided into the HIIT group (n = 8) and moderate-intensity continuous training (MICT, n = 8) group. The HIIT group underwent 20 min of exercise consisting of 20 s of high-intensity (85–90% HRmax) exercise followed by 30 s of exercise at 60% HRmax using only body weight. The main exercise program for the MICT group included 40 min of stationary bike pedaling at 65–70% HRmax. Exercise was performed three days a week for eight weeks using a smart device and application that enables bidirectional communication. Results: The HIIT group showed reduced body fat (p = 0.036), BMI (p = 0.021), and visceral fat (p = 0.003) compared to the MICT group. Further, the HIIT group also had reduced insulin (p = 0.021) and LDL levels (p = 0.024), increased grip strength (left p = 0.012, right: p = 0.002), and a substantial drop in total stress index (p = 0.004) compared to the MICT group. Conclusions: Thus, online HIIT is a useful means to reduce abdominal fat, improve blood lipid profile and muscle strength, and relieve stress caused by COVID-19.

Lack of Endothelial α1AMPK Reverses the Vascular Protective Effects of Exercise by Causing eNOS Uncoupling

Article

Full-text available

Dec 2021

Voluntary exercise training is an effective way to prevent cardiovascular disease, since it results in increased NO bioavailability and decreased reactive oxygen species (ROS) production. AMP-activated protein kinase (AMPK), especially its α1AMPK subunit, modulates ROS-dependent vascular homeostasis. Since endothelial cells play an important role in exercise-induced changes of vascular signaling, we examined the consequences of endothelial-specific α1AMPK deletion during voluntary exercise training. We generated a mouse strain with specific deletion of α1AMPK in endothelial cells (α1AMPKflox/flox x TekCre⁺). While voluntary exercise training improved endothelial function in wild-type mice, it had deleterious effects in mice lacking endothelial α1AMPK indicated by elevated reactive oxygen species production (measured by dihydroethidum fluorescence and 3-nitrotyrosine staining), eNOS uncoupling and endothelial dysfunction. Importantly, the expression of the phagocytic NADPH oxidase isoform (NOX-2) was down-regulated by exercise in control mice, whereas it was up-regulated in exercising α1AMPKflox/flox x TekCre⁺ animals. In addition, nitric oxide bioavailability was decreased and the antioxidant/protective nuclear factor erythroid 2-related factor 2 (Nrf-2) response via heme oxygenase 1 and uncoupling protein-2 (UCP-2) was impaired in exercising α1AMPKflox/flox x TekCre⁺ mice. Our results demonstrate that endothelial α1AMPK is a critical component of the signaling events that enable vascular protection in response to exercise. Moreover, they identify endothelial α1AMPK as a master switch that determines whether the effects of exercise on the vasculature are protective or detrimental.

Effect of High-Intensity Interval Training on Quality of Life, Sleep Quality, Exercise Motivation and Enjoyment in Sedentary People with Type 1 Diabetes Mellitus

Article

Full-text available

Nov 2021
Int J Environ Res Publ Health

Abstract:(1) Background: Type 1 diabetes mellitus (T1DM) people’s health-related quality of life(HRQoL) is affected by glycemic control. Regular exercise is strongly recommended to these patientsdue to its cardiovascular and metabolic benefits. However, a large percentage of patients withT1DM people present a sedentary behavior because of the fear of a post-exercise hypoglycemiaevent, lack of time, lack of motivation and the complicated management of exercise, glycemic andinsulin dose interaction. High-intensity interval training (HIIT) is an efficient and safe methodologysince it prevents hypoglycemia and does not require much time, which are the main barriers forthis population to doing exercise and increasing physical conditioning. (2) Methods: Nineteensedentary adults (37±6.5 years) with T1DM, were randomly assigned to 6 weeks of either HIIT(12-16-20×30-sintervals interspersed with 1-min rest periods) performed thrice weekly, or to thecontrol group, which did not train. HRQoL, sleep quality, exercise motivation and enjoyment weremeasured as psychological variables. (4) Results: HRQoL improved in physical and social domains,PF (1.9%); PR (80.3%); GH (16.6); SF (34.1%). Sleep quality improved in the HIIT group by 21.4%.Enjoyment improved by 7% and intrinsic motivation was increased by 13%. (5) Conclusions: Wesuggest that the 6-week HIIT program used in the present study is safe, since no severe hypoglycemiawere reported, and an effective strategy in improving HRQoL, sleep quality, exercise motivation andenjoyment which are important psychological well-being factors in T1DM people

Alternating high-intensity interval training and continuous training is efficacious in improving cardiometabolic health in obese middle-aged men

Article

Full-text available

Nov 2021
J EXERC SCI FIT

Background: High-intensity interval training (HIIT) or moderate-intensity continuous training (MICT) alone has been shown to improve metabolic health, but the effects of alternating the two training approaches as often practiced in real life remained unclear. Purpose: To examine the effects of HIIT or MICT alone or alternating HIIT-MICT on cardiometabolic responses in inactive obese middle-aged men. Methods: Forty-two participants (age: 42 ± 5 y; BMI: 26.3 ± 2.1 kg m-2) were randomly assigned to four groups: HIIT (12 x 1-min running bouts at 80-90% HRmax interspersed with 1-min active recovery at 50% HRmax), MICT (40-min brisk walk at 65-70% HRmax), alternating HIIT-MICT or a non-exercise control group (CON). Exercise sessions were conducted three times per week for 16 weeks. Maximal oxygen uptake (VO2max), body composition (by bioelectrical impedance analysis), blood pressure, fasting blood glucose, insulin resistance (HOMA-IR) and lipid profile were assessed at baseline and after the 16-week intervention. Enjoyment and self-efficacy were also assessed at the end of intervention. Results: All exercise groups showed a similar VO2max increase of ∼15% (HIIT: 34.3 ± 4.4 vs 39.1 ± 5.4; MICT: 34.9 ± 5.0 vs 39.4 ± 7.2; and alternating HIIT-MICT: 34.4 ± 5.0 vs 40.3 ± 4.6 mL kg-1min-1) compared to baseline and CON (all p < 0.05). Weight, BMI, % fat and waist circumference also showed similar reductions in all exercise groups compared to baseline and CON (all p < 0.05). No significant group difference was observed for all blood markers. Compared to baseline, total cholesterol decreased after HIIT-MICT, while HIIT significantly decreased fasting insulin level and improved insulin resistance (p < 0.05). Enjoyment, self-efficacy and adherence were similar among all exercise groups. Conclusion: HIIT or MICT alone or alternating HIIT-MICT similarly improve cardiovascular fitness and body composition in obese middle-aged men despite differences in total training volume and time commitment.

Left ventricular mechanical, cardiac autonomic and metabolic responses to a single session of high intensity interval training

Article

Full-text available

Feb 2022
EUR J APPL PHYSIOL

Purpose High-intensity interval training (HIIT) produces significant health benefits. However, the acute physiological responses to HIIT are poorly understood. Therefore, we aimed to measure the acute cardiac autonomic, haemodynamic, metabolic and left ventricular mechanical responses to a single HIIT session. Methods Fifty young, healthy participants completed a single HIIT session, comprising of three 30-s maximal exercise intervals on a cycle ergometer, interspersed with 2-min active recovery. Cardiac autonomics, haemodynamics and metabolic variables were measured pre-, during and post-HIIT. Conventional and speckle tracking echocardiography was used to record standard and tissue Doppler measures of left ventricular (LV) structure, function and mechanics pre- and post-HIIT. Results Following a single HIIT session, there was significant post-exercise systolic hypotension (126 ± 13 to 111 ± 10 mmHg, p < 0.05), parallel to a significant reduction in total peripheral resistance (1640 ± 365 to 639 ± 177 dyne⋅s⋅cm⁵, p < 0.001) and significant increases in baroreceptor reflex sensitivity and baroreceptor effectiveness index (9.2 ± 11 to 24.8 ± 16.7 ms⋅mmHg⁻¹ and 41.8 ± 28 to 68.8 ± 16.2, respectively) during recovery compared to baseline. There was also a significant increase in the low- to high-frequency heart rate variability ratio in recovery (0.7 ± 0.48 to 1.7 ± 1, p < 0.001) and significant improvements in left ventricular global longitudinal strain (− 18.3 ± 1.2% to − 29.2 ± 2.3%, p < 0.001), and myocardial twist mechanics (1.27 ± 0.72 to 1.98 ± 0.72°·cm⁻¹, p = 0.028) post-HIIT compared to baseline. Conclusion A single HIIT session is associated with acute improvements in autonomic modulation, haemodynamic cardiovascular control and left ventricular function, structure and mechanics. The acute responses to HIIT provide crucial mechanistic information, which may have significant acute and chronic clinical implications.

Clinical Exercise Considerations for Opioid Addiction Recovery

Article

Sep 2021

According to the American Psychiatric Association, in 2018, approximately 2 million Americans were suffering from a substance abuse disorder, defined as substance abuse and dependence (1), related to opioids that were prescribed for pain management (2), while worldwide, it is estimated this approaches 16 million (3). Consequently, exercise clinicians will be increasingly exposed to individuals who have been affected by opioids and should therefore know how these drugs affect physiological functioning and how exercise can play a role in opioid addiction recovery. This review article is intended to provide some of this information.

EFFECT OF HIGH INTENSITY INTERVAL TRAINING ON THE CARDIOVASCULAR SYSTEM AND CARDIAC ANTI-AGING

Article

Full-text available

May 2021

Olivia Dharmasanti

There are several risk factors leading to the development and progression of CVD, but one of the most prominent is a sedentary lifestyle. A healthy lifestyle can be characterized by both obesity and consistently low levels of physical activity. Lifestyle interventions that aim to increase physical activity and decrease obesity are attractive therapeutic methods to combat most non-congenital types of CVD. Aging is the another major risk factor for cardiovascular diseases (CVD), which are the leading cause of death in the United States. Epidemiological studies clearly show that aging itself is the major risk factor for cardiovascular and cerebrovascular diseases. Most of the research efforts on prevention of these diseases have ignored the mechanisms underlying cardiac and vascular effects of aging, and have focused, instead, on the development of interventions that target conventional cardiovascular risk factors. High-intensity interval training (HIIT) is frequently used in sports training. The effects on cardiorespiratory and muscle systems have led scientists to consider its application in the field of cardiovascular diseases. HIIT is defined as high intensity exercise for a defined period of time interspersed with rest periods (moderate light intensity or complete rest). This literature review was conducted to determine the correlation between high intensity interval training with the cardiovascular system and cardiac anti-aging. Keywords: Cardiac anti-aging, cardiovascular system, cardiovascular disease, high intensity interval training.

Effect of Mathematical Modeling and Fitting Procedures on the Assessment of Critical Speed and Its Relationship With Aerobic Fitness Parameters

Article

Full-text available

May 2021

An accurate estimation of critical speed (CS) is important to accurately define the boundary between heavy and severe intensity domains when prescribing exercise. Hence, our aim was to compare CS estimates obtained by statistically appropriate fitting procedures, i.e., regression analyses that correctly consider the dependent variables of the underlying models. A second aim was to determine the correlations between estimated CS and aerobic fitness parameters, i.e., ventilatory threshold, respiratory compensation point, and maximal rate of oxygen uptake. Sixteen male runners performed a maximal incremental aerobic test and four exhaustive runs at 90, 100, 110, and 120% of the peak speed of the incremental test on a treadmill. Then, two mathematically equivalent formulations (time as function of running speed and distance as function of running speed) of three different mathematical models (two-parameter, three-parameter, and three-parameter exponential) were employed to estimate CS, the distance that can be run above CS (d′), and if applicable, the maximal instantaneous running speed (smax). A significant effect of the mathematical model was observed when estimating CS, d′, and smax (P < 0.001), but there was no effect of the fitting procedure (P > 0.77). The three-parameter model had the best fit quality (smallest Akaike information criterion) of the CS estimates but the highest 90% confidence intervals and combined standard error of estimates (%SEE). The 90% CI and %SEE were similar when comparing the two fitting procedures for a given model. High and very high correlations were obtained between CS and aerobic fitness parameters for the three different models (r ≥ 0.77) as well as reasonably small SEE (SEE ≤ 6.8%). However, our results showed no further support for selecting the best mathematical model to estimate critical speed. Nonetheless, we suggest coaches choosing a mathematical model beforehand to define intensity domains and maintaining it over the running seasons.

Critical speed estimated by statistically appropriate fitting procedures

Article

Full-text available

Jul 2021
EUR J APPL PHYSIOL

Purpose Intensity domains are recommended when prescribing exercise. The distinction between heavy and severe domains is made by the critical speed (CS), therefore requiring a mathematically accurate estimation of CS. The different model variants (distance versus time, running speed versus time, time versus running speed, and distance versus running speed) are mathematically equivalent. Nevertheless, error minimization along the correct axis is important to estimate CS and the distance that can be run above CS ( d′ ). We hypothesized that comparing statistically appropriate fitting procedures, which minimize the error along the axis corresponding to the properly identified dependent variable, should provide similar estimations of CS and d ′ but that different estimations should be obtained when comparing statistically appropriate and inappropriate fitting procedure. Methods Sixteen male runners performed a maximal incremental aerobic test and four exhaustive runs at 90, 100, 110, and 120% of their peak speed on a treadmill. Several fitting procedures (a combination of a two-parameter model variant and regression analysis: weighted least square) were used to estimate CS and d ′. Results Systematic biases ( P < 0.001) were observed between each pair of fitting procedures for CS and d ′, even when comparing two statistically appropriate fitting procedures, though negligible, thus corroborating the hypothesis. Conclusion The differences suggest that a statistically appropriate fitting procedure should be chosen beforehand by the researcher. This is also important for coaches that need to prescribe training sessions to their athletes based on exercise intensity, and their choice should be maintained over the running seasons.

Cardioprotective effects of severe calorie restriction from birth in adult ovariectomized rats

Article

Full-text available

Mar 2021
LIFE SCI

Aims Menopause is a female condition induced by a reduction of ovarian hormone and is related to an increase in cardiovascular diseases in women. We have shown that severe calorie restriction (SCR) from birth reduces the cardiometabolic risk in adult male Wistar rats. In this study, we investigated the effects of SCR from birth to adulthood on cardiovascular function of ovariectomized rats. Main methods From birth to adulthood, rats were daily fed ad libitum (control group - C) or with 50% of the amount consumed by the control group (calorie-restricted group - R). At 90 days, half of the rats in each group underwent bilateral ovariectomy (OVX), totaling 4 groups: C-Sham, C-OVX, R-Sham, R-OVX. Systolic blood pressure (SBP), heart rate (HR) and, double product (DP) index were recorded by tail-cuff plethysmography. Cardiac function was analyzed by the Langendorff technique and cardiomyocyte diameter was accessed by histologic analysis. Additionally, cardiac SERCA2 content and redox status were evaluated. Key findings C-OVX rats exhibited reduced cardiac function and cardiac non-enzymatic total antioxidant capacity (TAC). R-Sham animals showed reduced SBP, DP, HR, improved cardiac function, reduced cardiac protein carbonyl derivatives and increased TAC, catalase, and superoxide dismutase activities. R-OVX rats maintained reduced SBP, DP, HR, and increased contractility and relaxation indexes. R-Sham and R-OVX rats exhibited preserved heart mass and reduced cardiomyocyte diameter. Cardiac SERCA2 content did not differ between the groups. Significance Taken together, our findings show cardioprotective effects of SCR from birth in adult ovariectomized rats.

The Effects of Very Low Energy Diets and Low Energy Diets with Exercise Training on Skeletal Muscle Mass: A Narrative Review

Article

Full-text available

Nov 2020

In recent years, very-low-energy diets (VLEDs) have been recognised as a viable strategy for improving the extent of weight loss and cardio-metabolic outcomes in people who are either overweight or obese. However, concerns exist regarding the reductions in lean body mass (LBM) during VLEDs, particularly in vulnerable demographic groups, such as middle-aged and older adults already prone to developing sarcopenia. Sarcopenia is itself associated with multiple adverse outcomes, including frailty, cardio-metabolic deterioration and increased mortality. Therefore, a number of studies investigating strategies to ameliorate this detrimental effect of VLEDs have attempted to address this concern. This narrative review explores the potential benefits and limitations of exercise and/or protein supplementation for LBM retention during VLEDs based on the available evidence. Current studies suggest that both protein supplementation and exercise training may result in improved LBM retention (and skeletal muscle function) during VLEDs. However, uncertainty remains concerning the interactions between intervention types, based on discordant outcomes reported in the literature and the heterogeneity of exercise modalities in achieving this particular outcome.

A Pilot Study on In-Task Affect Predicting Free-Living Adherence to HIIT and MICT

Article

Oct 2020

Purpose: To report pilot test findings on whether in-task affect during a supervised exercise program, where participants were randomized to either moderate-intensity continuous training (MICT) or high-intensity interval training (HIIT), predicts changes in moderate-to-vigorous physical activity (MVPA-Total and MVPA10+ in bouts of ≥ 10 min) at 1- and 6-month post-intervention. Method: This experimental study design randomized 32 inactive adults with prediabetes to complete a 2-week supervised MICT or HIIT plus behavioral counseling exercise intervention and objectively assessed free-living physical activity post-intervention. The Feeling Scale (FS) was used to assess the in-task effect. FS was measured in the middle of four, 1-min intervals in the HIIT condition, corresponding to ~20%, ~50%, ~75%, and ~85% of work out time. For the MICT condition, FS was assessed at similar exercise duration percentage times as HIIT. Accelerometer data evaluated MVPA at 1- and 6-month post-intervention. Results: 32 adults were included in the analyses. Pilot findings indicated in-task affect between the conditions did not predict changes in MVPA-Total from baseline to 1 and 6 months. For MVPA10+, in-task affect negatively predicted MVPA10+ over time in the MICT condition only. Conclusion: This study provides preliminary evidence that affect during MICT negatively predicts MVPA10+ over time, and that there is no difference of in-task affect’s utility in predicting MVPA-Total between HIIT and MICT. Larger studies are required to confirm these findings.

The role of resistance exercise-induced local metabolic stress in mediating systemic health and functional adaptations: could condensed training volume unlock greater benefits beyond time efficiency?

Article

Full-text available

Apr 2025

Ivan Curovic

The majority of “specialised” exercise configurations (e.g., supersets, drop sets, blood flow restriction) are being assessed as “shortcuts” to hypertrophy and strength improvements. However, these advanced training techniques may also offer significant benefits for systemic health and functional outcomes across recreational and clinical populations via locally induced metabolic responses. Stress-regulating mechanisms are known to enhance the body’s resilience by facilitating allostasis, the process of coordinating adaptive processes in reaction to stressors such as physical training. Yet, the role of the local metabolic stress provoked by resistance exercise has not gained much research attention despite its wide potential. Positive effects are not only linked to improved muscular endurance, hypertrophy and strength via primary and secondary mechanisms, but also to the release of myokines, hormones, microRNAs, immune factors, inflammatory substances and other endocrine molecules that initiate numerous health-promoting modifications on a systemic level. Resistance exercise strategies that maximise the local accumulation of metabolites are not well defined, although high volume, close proximity to failure and shorter rests seem to be a necessity. Additionally, blood flow restriction training provides a potent alternative for inducing local acidosis, thereby triggering several pathways associated with improved immunity and physical function even in remote muscle tissues. Future research is warranted to further explore advanced resistance training techniques, as these approaches may offer comparable benefits for physical and mental health to those seen with other forms of exercise such as high-intensity interval training and heavy resistance training.

Effects of high‐intensity interval training on depressive and anxiety symptoms in healthy individuals: A systematic review and meta‐analysis of randomized clinical trials

Article

Full-text available

Apr 2024
SCAND J MED SCI SPOR

Although evidence regarding the effects of high‐intensity interval training (HIIT) on mental health has increased in recent years, there is still no consensus regarding the effects of HIIT on the symptoms of depression and anxiety in a healthy population. Therefore, this systematic review aimed to investigate the effects of HIIT on depressive and/or anxiety symptoms in healthy individuals. The following four databases were searched: PubMed, Scopus, Embase, and PsycINFO. Only randomized clinical trials (RCTs) were included. We performed a random‐effects meta‐analysis based on standardized mean difference (SMD). The risk of bias was assessed using the RoB 2.0 tool, and the certainty of the evidence was evaluated based on recommendations GRADE. Eight RCTs evaluating 471 participants (81% female) were considered eligible for inclusion. The results of the meta‐analysis showed that HIIT‐based interventions had no significant effect on reducing anxiety (SMD = −0.17; 95% CI: −0.53, 0.19; p = 0.27) and depressive symptoms (SMD = −0.38; 95% CI: −1.06, 0.30; p = 0.17) compared with the passive control group. In conclusion, HIIT does not improve symptoms of depression and anxiety in healthy individuals. This finding is based on evidence of very low certainty. Therefore, the evidence is still not consistent enough to support HIIT as a viable strategy to reduce both outcomes because of the limited number of included studies and the overall quality of evidence.

Rates of compliance and adherence to high-intensity interval training: a systematic review and Meta-analyses

Article

Full-text available

Nov 2023
INT J BEHAV NUTR PHY

Background To determine rates of compliance (i.e., supervised intervention attendance) and adherence (i.e., unsupervised physical activity completion) to high-intensity interval training (HIIT) among insufficiently active adults and adults with a medical condition, and determine whether compliance and adherence rates were different between HIIT and moderate-intensity continuous training (MICT). Methods Articles on adults in a HIIT intervention and who were either insufficiently active or had a medical condition were included. MEDLINE, EMBASE, PsychINFO, SPORTDiscus, CINAHL, and Web of Science were searched. Article screening and data extraction were completed by two independent reviewers. Risk of bias was assessed using RoB 2.0 or ROBINS-I. Meta-analyses were conducted to discern differences in compliance and adherence between HIIT vs. MICT. Sensitivity analyses, publication bias, sub-group analyses, and quality appraisal were conducted for each meta-analysis. Results One hundred eighty-eight unique studies were included (n = 8928 participants). Compliance to HIIT interventions averaged 89.4% (SD:11.8%), while adherence to HIIT averaged 63% (SD: 21.1%). Compliance and adherence to MICT averaged 92.5% (SD:10.6%) and 68.2% (SD:16.2%), respectively. Based on 65 studies included in the meta-analysis, compliance rates were not different between supervised HIIT and MICT interventions [Hedge’s g = 0.015 (95%CI: − 0.088–0.118), p = .78]. Results were robust and low risk of publication bias was detected. No differences were detected based on sub-group analyses comparing medical conditions or risk of bias of studies. Quality of the evidence was rated as moderate over concerns in the directness of the evidence. Based on 10 studies, adherence rates were not different between unsupervised HIIT and MICT interventions [Hedge’s g = − 0.313 (95%CI: − 0.681–0.056), p = .096]. Sub-group analysis points to differences in adherence rates dependent on the method of outcome measurement. Adherence results should be interpreted with caution due to very low quality of evidence. Conclusions Compliance to HIIT and MICT was high among insufficiently active adults and adults with a medical condition. Adherence to HIIT and MICT was relatively moderate, although there was high heterogeneity and very low quality of evidence. Further research should take into consideration exercise protocols employed, methods of outcome measurement, and measurement timepoints. Registration This review was registered in the PROSPERO database and given the identifier CRD42019103313.

Psychological and Physiological Responses Across Six Weeks of HIIT and MICT in Previously Inactive, Young Adults

Article

Jun 2023

Unlabelled: High-intensity interval training (HIIT) is suggested as a public health strategy to increase engagement in, and adherence to, physical activity. However, debate exists regarding the efficacy in inactive individuals. Purpose: To determine the physiological and psychological responses to three weeks of supervised and three weeks of unsupervised HIIT or moderate-intensity continuous training (MICT) in previously inactive adults. Methods: Young adults (n = 20; 21.4 ± 2.2 years; 13 females) were randomized to six weeks of HIIT or MICT. Pre- and post-testing included anthropometric measures, an incremental exercise test, and body composition. Psychological outcomes (i.e., perceived competence, self-efficacy, and enjoyment) were assessed at the end of the first, ninth, and eighteenth training sessions. Differences in physiological outcomes were analyzed using repeated measures factorial ANCOVAs. Differences in psychological outcomes were analyzed using repeated measures factorial ANOVAs. Results: Maximal oxygen consumption (Δ 2.8 ml·kg-1·min-1; p = .03) and peak power output (Δ 20.2 W; p = .01) improved over time with no group differences (p > .05). No changes occurred in body composition or self-efficacy (p ≥ .27). Perceived competence increased with supervised training (p = .01) with no further increases during unsupervised training. There was no difference in enjoyment across supervised training (p = .07), but enjoyment decreased during unsupervised training (p = .003). Conclusions: Cardiorespiratory fitness improved comparably for HIIT and MICT but with a shorter time commitment for HIIT. Perceived competence increased across supervised training suggesting it may be important to provide support at the beginning of an exercise intervention.

Treinamento intervalado de alta intensidade no processo de emagrecimento: Um estudo de revisão bibliográfica integrativa

Chapter

Full-text available

Jun 2023

O HIIT com suas duas derivações o sprint interval training (SIT) e continuous training (CT), de forma de circuito e velocidade, depois das análises foi comprovado que o SIT teve o maior desempenho em relação CT, há uma diferença na taxa metabólica no caso uma diminuição ao fim do exercício. A obesidade de acordo com a Organização Mundial de Saúde (OMS), é uma condição de caráter multifatorial que favorece o acumulo de gordura que por sua vez está associado a risco na saúde, devido sua relação com complicações metabólicas. A fim de melhorar a condição de vida dessas pessoas evitando que outras cheguem a esse quadro, diversos estudos vêm sendo realizado no Brasil e no mundo na intenção de encontrar a melhor intervenção contra a obesidade. O treinamento intervalado de alta intensidade (HIIT) que consiste na alternância de exercício em alta intensidade seguido por um período de intervalo que pode ser passivo ou ativo, tem se mostrado eficiente no combate a obesidade, essa modalidade embora tenha um pequeno tempo de duração quando se fala do SIT e RST tem uma contribuição maior de carboidratos durante sua execução, após o exercício há uma maior oxidação de gordura devido ao consumo EPOC.

The Effect of High Intensity Interval Training on Body Composition in Obesity Patients: Literature Review: Literature Review

Article

Full-text available

May 2023

Obesity is a major threat to health in various parts of the world. This study will also elaborate further on the effects of HIIT on body composition in obese people. This study uses the literature review method using articles from the last 3 to 9 years. Articles searched through ScienceDirect were 348, MDPI were 29 articles, Scopus were 178 and Springer were 317, so the total population of articles found was 872. This study used Preferred Reporting Items for Systematic Reviews and Meta Analyzes and found a sample of 12 articles. The results of the study revealed that there was a decrease in fat mass of 0.16 kg, 1.81 kg to 4.7 kg, and as much as 0.4 liters of total body water reduction, besides that waist circumference also decreased, but it was different from fat-free body mass which increased by 0.55 kg. In conclusion, HIIT can reduce body composition in the form of fat mass, total body water and waist circumference for obese people, but there is an increase in fat-free body mass.

High-intensity Interval Training for the Management of Nonalcoholic Steatohepatitis: Participant Experiences and Perspectives

Article

Full-text available

Apr 2023

Background and Aims High-intensity interval training (HIIT) is a therapeutic option for people with nonalcoholic steatohepatitis (NASH). However, the perspectives and experiences of HIIT for people with NASH are unknown, limiting translation of research. We explored the experiences and perspectives of both professionally supervised and self-directed HIIT in people with NASH and evaluated participant-reported knowledge, barriers, and enablers to commencing and sustaining HIIT. Methods Twelve participants with NASH underwent 12 weeks of supervised HIIT (3 days/week, 4×4 minutes at 85–95% maximal heart rate, interspersed with 3 minutes active recovery), followed by 12-weeks of self-directed (unsupervised) HIIT. One-on-one, semistructured participant interviews were conducted by exercise staff prior to HIIT and following both supervised and self-directed HIIT to explore prior knowledge, barriers, enablers, and outcomes at each stage. Interviews were audio-recorded, transcribed, coded, and thematically analyzed by two independent researchers. Results Four dominant themes were identified: (1) no awareness of/experience with HIIT and ambivalence about exercise capabilities; (2) multiple medical and social barriers to commencing and continuing HIIT; (3) exercise specialist support was a highly valued enabler, and (4) HIIT was enjoyed and provided holistic benefits. Conclusions People with NASH may lack knowledge of and confidence for HIIT, and experience multiple complex barriers to commencing and continuing HIIT. Exercise specialist support is a key enabler to sustained engagement. These factors need to be addressed in future clinical programs to augment the uptake and long-term sustainability of HIIT by people with NASH so they can experience the range of related benefits.

Effects of Aquabike Exercise on Gait Ability, Cardiovascular and Fall-related Fitness in Older Women with Obesity

Article

Full-text available

Feb 2023

PURPOSE: This study aimed to verify the effects of aquabike exercise on the gait ability and cardiorespiratory and fall-related fitness of older women with obesity.METHODS: The participants were divided into 65–74 years old and 75–82 years old groups. Verified cardiorespiratory fitness and physical changes were compared between the groups. The aquabike exercise used in this study was a combination of water exercise and a fixed bicycle on the ground. A 50-min aquabike exercise was performed three times weekly for 12 weeks.RESULTS: Our study’s results revealed that cardiorespiratory fitness did not show any significant changes between the groups × period of forced expiratory volume, maximum 80% exercise duration, maximum heart rate, and pedals per minute. The number of revolutions increased significantly after the exercise. In relation to gait, there was no significant change between the group × period of time required for walking 6 m and the number of steps, whereas the time required and the number of steps required to walk for 6 m within the groups significantly decreased after exercise. There were no significant changes between the groups × period in 3-m round-trip, five chair-standing, 30-s chair-standing, and relative grip strength of fall-related physical variables; however, the time required to walk a 3-m round-trip and five chair-to-stand within the groups decreased after aquabike exercise.CONCLUSIONS: Aquabike exercise is an effective mediation strategy for older women with obesity, as it is an exercise method that maintains a vibrant life in older age groups as well as walking ability by improving cardiopulmonary and fall-related physical strength.

The effects of qigong intervention based on the Internet on quality of life and physical fitness in Chinese postoperative breast cancer patients: a protocol of randomized controlled trial

Article

Full-text available

Mar 2023
TRIALS

Background The purpose of this study is to verify the improvement of remote qigong intervention on the quality of life and physical fitness of breast cancer patients after surgery by means of a randomized controlled trial and to compare it with the conventional exercise combination of aerobic exercise and resistance training. Methods/design The research approach applied in this study is a randomized controlled trial. After completing the baseline questionnaire and physical fitness test, participants were randomly assigned to either the qigong group or the combined exercise rehabilitation group. Patients in the qigong group performed Qigong-Baduanjin twice a week for 30 min each time under remote guidance and practiced Baduanjin by themselves at other times. Patients in the combined exercise rehabilitation group were given resistance training twice a week for 30 min under remote guidance, and walking the rest of the time. At the end of the 12-week intervention, outcomes testing and data collection were carried out. The primary outcomes are quality of life, measured using the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), and the Functional Assessment of Cancer Therapy-Breast (FATC-B). The secondary outcomes include cardiopulmonary endurance, upper limb strength, lower limb strength, and skinfold thickness. Discussion The importance of postoperative exercise rehabilitation for breast cancer has been gradually accepted by more and more doctors and patients, but further research and development of simple and practical means of exercise rehabilitation are necessary. Remote qigong intervention for breast cancer patients via the Internet will be a great alternative. Trial registration Chinese Clinical Trial Registry ChiCTR1900027989. Registered on December 7, 2019.

Effects of the intensity of interval training on aerobic fitness, body composition and resting metabolic rate of women with overweight or obesity: A randomized trial

Article

Oct 2022

BACKGROUND Moderate-intensity interval training (MIIT) may be a viable exercise format for improving body composition, aerobic fitness, and health-related variables. OBJECTIVES This randomized trial aimed to analyze the effect of MIIT or high-intensity interval training (HIIT) on aerobic fitness, body composition variables, and resting metabolic rate (RMR) in women with overweight or obesity. METHODS 31 sedentary adult women with overweight or obesity performed 7 weeks [Formula: see text] 3 weekly sessions of either HIIT or MIIT. Physical and physiological tests were applied before and after training. RESULTS In both analyses (intention-to-treat and by adherence to the training), aerobic fitness showed a time effect ([Formula: see text] 0.041 and [Formula: see text] 0.015), but without differences between groups ([Formula: see text] 0.05). No group (HIIT vs. MIIT), time (pre vs. post), or interaction effects (group vs. time) were found for RMR, body composition markers (fat mass, body fat percentage, lean mass), or body mass index – BMI ([Formula: see text] 0.05). In addition, MIIT induced a relatively high drop-out rate. CONCLUSIONS This study suggested that the short-term (7-weeks) interval exercise training was effective for increasing aerobic fitness, and moderate-intensity intervals were as effective as high-intensity intervals. However, neither training format was effective for changing RMR, body composition variables, or BMI of women with overweight or obesity. Clinical trial ID: RBR-9jd7b7.

Extraordinary claims in the literature on high-intensity interval training (HIIT): IV. Is HIIT associated with higher long-term exercise adherence?

Article

Sep 2022
PSYCHOL SPORT EXERC

Nonadherence to and dropout from regular exercise and physical activity are important reasons why the field of exercise science has yet to fulfill its promise of improving public health on a global scale. Researchers have claimed that High-Intensity Interval Training (HIIT) is a feasible and sustainable exercise modality that may result in higher long-term adherence than moderate-intensity continuous exercise. If true, this would be a breakthrough discovery that could unlock the potential of exercise as a health-promoting intervention. We performed a systematic search of the literature and identified eight trials comparing HIIT to moderate-intensity continuous exercise, all of which involved follow-up periods of at least 12 months (i.e., SWIFT, Small Steps for Big Changes, SAINTEX-CAD, SMARTEX-HF, Generation 100, FITR, OptimEx-Clin, HITTS). Findings from these trials demonstrate that, while unsupervised, individuals initially assigned to HIIT tend to exercise at lower-than-prescribed intensities and HIIT groups demonstrate no advantage in long-term adherence.

HIIT na doença cardiometabólica

Presentation

Full-text available

Jul 2022

The main goal is to identify inside the literature the most effective dose-response in terms of volume and methodological intensities of HIIT protocols in cardiometabolic disease. In this congress, I intend to propose alternatives to the constraints in the application of laboratory protocols in a professional context

HIGH-INTENSITY INTERVAL TRAINING

Presentation

Full-text available

Apr 2022

The main goal is to identify inside the literature the most effective dose-response in terms of volume and methodological intensities of HIIT protocols. In this congress, I intend to propose alternatives to the constraints in the application of laboratory protocols in a professional context

Self-paced HIIT is less physiologically demanding than traditional HIIT

Article

Feb 2022
Gazz Med Ital

Clinical review and role of clinical pharmacists in obesity management: An opinion of the Endocrine and Metabolism Practice and Research Network of the American College of Clinical Pharmacy

Article

Aug 2021

The objective of this practice and research network opinion paper was to identify literature for pharmacist‐led services with obesity management, summarize clinical evidence for this disease state, and describe the role of a clinical pharmacist among patients who are overweight or have obesity. Clinical pharmacists play a critical role in the safe and effective management of obesity in both the inpatient and outpatient settings. In an outpatient setting, the role of the clinical pharmacist includes a comprehensive patient interview to design an individualized therapeutic plan involving non‐pharmacological interventions with or without pharmacological interventions or surgical options. A clinical pharmacist conducts a risk‐benefit analysis for pharmacological interventions. Furthermore, the potential of medications to contribute to weight gain or prevent weight loss can be reviewed by a clinical pharmacist when managing comorbid conditions. In an inpatient setting, a clinical pharmacist conducts medication reconciliation, determines appropriate supplements for nutritional deficiencies, and provides medication management for people with obesity who may or may not be undergoing bariatric surgery. In addition, a clinical pharmacist can provide thorough patient education with monitoring for transitions from hospital to the outpatient setting and subsequent follow‐up visits. This article is protected by copyright. All rights reserved.

Effects of high-intensity interval training in more or less active mice on biomechanical, biophysical and biochemical bone parameters

Article

Full-text available

Mar 2021

High-intensity interval training (HIIT) is of scientific interest due its role in improving physical fitness, but the effects of HIIT on bone health need be carefully explored. Further, it is necessary to know whether HIIT effects on bone health are dependent on the physical activity levels. This may be experimentally tested since we have built a large cage (LC) that allows animals to move freely, promoting an increase of spontaneous physical activity (SPA) in comparison to a small cage (SC). Thus, we examined the effects of HIIT on biophysical, biomechanical and biochemical parameters of bone tissue of C57BL/6J mice living in cages of two different sizes: small (SC) or large (LC) cages with 1320 cm² and 4800 cm² floor space, respectively. Male mice were subdivided into two groups within each housing type: Control (C) and Trained (T). At the end of the interventions, all mice were euthanized to extract the femur bone for biophysical, biomechanical and biochemical analyses. Based a significant interaction from two-way ANOVA, trained mice kept in large cage (but not for trained mice housed in SC) exhibited a reduction of tenacity and displacement at failure in bone. This suggests that long-term HIIT program, in addition with a more active lifestyle correlates with exerts negative effects on the bone of healthy mice. A caution must also be raised about the excessive adoption of physical training, at least regarding bone tissue. On the other hand, increased calcium was found in femur of mice housed in LC. In line with this, LC-C mice were more active (i.e. SPA) than other groups. This implies that an active lifestyle without long-term high intensity physical training seems to play a role in promoting benefits to bone tissue. Our data provides new insights for treatment of osteo-health related disorders.

Recommandations fondées sur des données probantes visant à aider les adultes atteints de dépression à rester actifs toute leur vie

Article

Oct 2020

Résumé La dépression est aujourd’hui le trouble mental le plus répandu, et on estime qu’un Canadien sur quatre en souffrira à un moment ou à un autre de sa vie. Même si l’activité physique est recommandée comme traitement principal de la dépression légère à modérée et comme traitement secondaire de la dépression modérée à grave, on ne dispose toujours pas de lignes directrices précises sur la meilleure façon de promouvoir l’activité physique auprès de la population atteinte de dépression. Cet exposé de politique vise donc à fournir des recommandations fondées sur des données probantes aux fournisseurs de soins primaires et aux professionnels paramédicaux afin de promouvoir l’activité physique à vie chez les personnes atteintes de dépression. Ces recommandations consistent notamment à demander la permission de parler d’activité physique avec les personnes concernées; à présenter l’activité physique comme un élément sur lequel elles ont un contrôle afin de se sentir mieux; à préciser qu’intégrer ne serait-ce que quelques minutes supplémentaires d’activité physique hebdomadaire vaut mieux que rien et que des exercices légers sont suffisants pour obtenir des bienfaits sur la santé mentale et enfin à proposer plusieurs choix d’activités et essayer d’accompagner les personnes lors de leurs premières séances. En outre, cet article souligne l’importance de promouvoir, auprès de cette population, le plaisir que procure l’activité physique, ce qui peut être fait en aidant la personne à augmenter progressivement la fréquence, la durée et l’intensité de l’activité; en l’encourageant à faire preuve de bienveillance envers ellemême à propos de l’activité physique; en lui suggérant de s’adonner à une activité de plein air, d’écouter de la musique, d’être accompagnée d’un(e) ami(e) ou de faire partie d’un groupe; en utilisant un système d’autosuivi ou un journal pour renforcer le lien entre activité physique et amélioration de l’humeur. Les praticiens sont encouragés à utiliser ces recommandations fondées sur des données probantes (en particulier l’offre d’un maximum de choix, l’insistance sur le plaisir procuré par l’activité physique et la mise en avant des préférences personnelles) afin d’aider les personnes atteintes de dépression à bouger, à se rétablir et à s’épanouir. Ces recommandations sont également utilisables pour concevoir les futures interventions et pour éclairer les lignes directrices visant à réduire les taux de dépression au Canada.

Association of “Weekend Warrior” and Other Leisure Time Physical Activity Patterns With Risks for All-Cause, Cardiovascular Disease, and Cancer Mortality

Article

Full-text available

Jan 2017

Importance: More research is required to clarify the association between physical activity and health in "weekend warriors" who perform all their exercise in 1 or 2 sessions per week. Objective: To investigate associations between the weekend warrior and other physical activity patterns and the risks for all-cause, cardiovascular disease (CVD), and cancer mortality. Design, setting, and participants: This pooled analysis of household-based surveillance studies included 11 cohorts of respondents to the Health Survey for England and Scottish Health Survey with prospective linkage to mortality records. Respondents 40 years or older were included in the analysis. Data were collected from 1994 to 2012 and analyzed in 2016. Exposures: Self-reported leisure time physical activity, with activity patterns defined as inactive (reporting no moderate- or vigorous-intensity activities), insufficiently active (reporting <150 min/wk in moderate-intensity and <75 min/wk in vigorous-intensity activities), weekend warrior (reporting ≥150 min/wk in moderate-intensity or ≥75 min/wk in vigorous-intensity activities from 1 or 2 sessions), and regularly active (reporting ≥150 min/wk in moderate-intensity or ≥75 min/wk in vigorous-intensity activities from ≥3 sessions). The insufficiently active participants were also characterized by physical activity frequency. Main outcomes and measures: All-cause, CVD, and cancer mortality ascertained from death certificates. Results: Among the 63 591 adult respondents (45.9% male; 44.1% female; mean [SD] age, 58.6 [11.9] years), 8802 deaths from all causes, 2780 deaths from CVD, and 2526 from cancer occurred during 561 159 person-years of follow-up. Compared with the inactive participants, the hazard ratio (HR) for all-cause mortality was 0.66 (95% CI, 0.62-0.72) in insufficiently active participants who reported 1 to 2 sessions per week, 0.70 (95% CI, 0.60-0.82) in weekend warrior participants, and 0.65 (95% CI, 0.58-0.73) in regularly active participants. Compared with the inactive participants, the HR for CVD mortality was 0.60 (95% CI, 0.52-0.69) in insufficiently active participants who reported 1 or 2 sessions per week, 0.60 (95% CI, 0.45-0.82) in weekend warrior participants, and 0.59 (95% CI, 0.48-0.73) in regularly active participants. Compared with the inactive participants, the HR for cancer mortality was 0.83 (95% CI, 0.73-0.94) in insufficiently active participants who reported 1 or 2 sessions per week, 0.82 (95% CI, 0.63-1.06) in weekend warrior participants, and 0.79 (95% CI, 0.66-0.94) in regularly active participants. Conclusions and relevance: Weekend warrior and other leisure time physical activity patterns characterized by 1 or 2 sessions per week may be sufficient to reduce all-cause, CVD, and cancer mortality risks regardless of adherence to prevailing physical activity guidelines.

High-intensity interval training: Key data needed to bridge the gap from laboratory to public health policy

Article

Full-text available

Mar 2016

The World Health Organization and a number of national bodies recommend adults undertake at least 150 min/week of moderate intensity physical activity, or 75 min/week of vigorous intensity physical activity. However, a large proportion of the population do not achieve these targets. Lack of time is often cited as a primary barrier,1 and many researchers have suggested that high-intensity interval training (HIIT), with interval durations from 10 s to 4 min and intensities ranging from 85% maximal heart rate (HRmax) to ‘all out’ efforts, may provide a time-efficient solution to improve public health.2 A wealth of evidence has demonstrated that HIIT can elicit a range of health benefits such as improved cardiorespiratory fitness, insulin sensitivity and vascular function, with these benefits being of at least a similar magnitude to those seen with standard moderate intensity physical activity interventions.3 ,4 These data are clear and convincing. However, they largely emanate from …

High-intensity interval exercise training for public health: A big HIT or shall we HIT it on the head?

Article

Full-text available

Jul 2015
INT J BEHAV NUTR PHY

Background: The efficacy of high-intensity interval training for a broad spectrum of cardio-metabolic health outcomes is not in question. Rather, the effectiveness of this form of exercise is at stake. In this paper we debate the issues concerning the likely success or failure of high-intensity interval training interventions for population-level health promotion. Discussion: Biddle maintains that high-intensity interval training cannot be a viable public health strategy as it will not be adopted or maintained by many people. This conclusion is based on an analysis of perceptions of competence, the psychologically aversive nature of high-intensity exercise, the affective component of attitudes, the less conscious elements of motivated behaviour that reflect our likes and dislikes, and analysis using the RE-AIM framework. Batterham argues that this appraisal is based on a constrained and outmoded definition of high-intensity interval training and that truly practical and scalable protocols have been - and continue to be - developed. He contends that the purported displeasure associated with this type of exercise has been overstated. Biddle suggests that the way forward is to help the least active become more active rather than the already active to do more. Batterham claims that traditional physical activity promotion has been a spectacular failure. He proposes that, within an evolutionary health promotion framework, high-intensity interval training could be a successful population strategy for producing rapid physiological adaptations benefiting public health, independent of changes in total physical activity energy expenditure. Summary: Biddle recommends that we focus our attention elsewhere if we want population-level gains in physical activity impacting public health. His conclusion is based on his belief that high-intensity interval training interventions will have limited reach, effectiveness, and adoption, and poor implementation and maintenance. In contrast, Batterham maintains that there is genuine potential for scalable, enjoyable high-intensity interval exercise interventions to contribute substantially to addressing areas of public health priority, including prevention and treatment of Type 2 diabetes and cardiovascular disease.

Determining how best to support overweight adults to adhere to lifestyle change: Protocol for the SWIFT study

Article

Full-text available

Sep 2015
BMC PUBLIC HEALTH

Background: Physical activity plays a critical role in health, including for effective weight maintenance, but adherence to guidelines is often poor. Similarly, although debate continues over whether a "best" diet exists for weight control, meta-analyses suggest little difference in outcomes between diets differing markedly in macronutrient composition, particularly over the longer-term. Thus a more important question is how best to encourage adherence to appropriate lifestyle change. While brief support is effective, it has on-going cost implications. While self-monitoring (weight, diet, physical activity) is a cornerstone of effective weight management, little formal evaluation of the role that self-monitoring technology can play in enhancing adherence to change has occurred to date. People who eat in response to hunger have improved weight control, yet how best to train individuals to recognise when true physical hunger occurs and to limit consumption to those times, requires further study. Methods/design: SWIFT (Support strategies for Whole-food diets, Intermittent Fasting, and Training) is a two-year randomised controlled trial in 250 overweight (body mass index of 27 or greater) adults that will examine different ways of supporting people to make appropriate changes to diet and exercise habits for long-term weight control. Participants will be randomised to one of five intervention groups: control, brief support (monthly weigh-ins and meeting), app (use of MyFitnessPal with limited support), daily self-weighing (with brief monthly feedback), or hunger training (four-week programme which trains individuals to only eat when physically hungry) for 24 months. Outcome assessments include weight, waist circumference, body composition (dual-energy x-ray absorptiometry), inflammatory markers, blood lipids, adiponectin and ghrelin, blood pressure, diet (3-day diet records), physical activity (accelerometry) and aerobic fitness, and eating behaviour. SWIFT is powered to detect clinically important differences of 4 kg in body weight and 5 cm in waist circumference. Our pragmatic trial also allows participants to choose one of several dietary (Mediterranean, modified Paleo, intermittent fasting) and exercise (current recommendations, high-intensity interval training) approaches before being randomised to a support strategy. Discussion: SWIFT will compare four different ways of supporting overweight adults to lose weight while following a diet and exercise plan of their choice, an aspect we believe will enhance adherence and thus success with weight management. Trial registration: Australian and New Zealand Clinical Trials Registry ACTRN12615000010594 . Registered 8(th) January 2015.

The effects of high-intensity interval training on glucose regulation and insulin resistance: A meta-analysis

Article

Full-text available

Aug 2015
OBES REV

The aim of this meta-analysis was to quantify the effects of high-intensity interval training (HIIT) on markers of glucose regulation and insulin resistance compared to control conditions (CON) or continuous training (CT). Databases were searched for HIIT interventions based on the inclusion criteria: training ≥2 weeks, adult participants, and outcome measurements that included insulin resistance, fasting glucose, HbA1c or fasting insulin. Dual interventions and participants with type 1 diabetes were excluded. Fifty studies were included. There was a reduction in insulin resistance following HIIT compared to both CON & CT, (HIIT vs. CON: standardised mean difference (SMD)=-0.49, confidence intervals (CI) -0.87 to -0.12, p=0.009; CT: SMD=-0.35, -0.68 to -0.02, p=0.036). Compared to CON, HbA1c decreased by 0.19% (-0.36 to -0.03, p=0.021) and body weight decreased by 1.3kg (-1.9 to -0.7, p<0.001). There were no statistically significant differences between groups in other outcomes overall. However, participants with or at risk of Type 2 diabetes experienced reductions in fasting glucose (-0.92mmol.L-1, -1.22 to -0.62, p<0.001) compared to CON. HIIT appears effective at improving metabolic health, particularly in those at risk of or with Type 2 diabetes. Larger randomised controlled trials of longer duration than those included in this meta-analysis are required to confirm these results.

24 h Accelerometry: impact of sleep-screening methods on estimates of sedentary behaviour and physical activity while awake

Article

Full-text available

Jul 2015
J SPORT SCI

Although accelerometers can assess sleep and activity over 24 h, sleep data must be removed before physical activity and sedentary time can be examined appropriately. We compared the effect of 6 different sleep-scoring rules on physical activity and sedentary time. Activity and sleep were obtained by accelerometry (ActiGraph GT3X) over 7 days in 291 children (51.3% overweight or obese) aged 4-8.9 years. Three methods removed sleep using individualised time filters and two methods applied standard time filters to remove sleep each day (9 pm-6 am, 12 am-6 am). The final method did not remove sleep but simply defined non-wear as at least 60 min of consecutive zeros over the 24-h period. Different methods of removing sleep from 24-h data markedly affect estimates of sedentary time, yielding values ranging from 556 to 1145 min/day. Estimates of non-wear time (33-193 min), wear time (736-1337 min) and counts per minute (384-658) also showed considerable variation. By contrast, estimates of moderate-to-vigorous activity (MVPA) were similar, varying by less than 1 min/day. Different scoring methods to remove sleep from 24-h accelerometry data do not affect measures of MVPA, whereas estimates of counts per minute and sedentary time depend considerably on which technique is used.

What Doesn't Kill You Makes You Fitter: A Systematic Review of High-Intensity Interval Exercise for Patients with Cardiovascular and Metabolic Diseases

Article

Full-text available

Jun 2015

High-intensity interval exercise (HIIE) has gained popularity in recent years for patients with cardiovascular and metabolic diseases. Despite potential benefits, concerns remain about the safety of the acute response (during and/or within 24 hours postexercise) to a single session of HIIE for these cohorts. Therefore, the aim of this study was to perform a systematic review to evaluate the safety of acute HIIE for people with cardiometabolic diseases. Electronic databases were searched for studies published prior to January 2015, which reported the acute responses of patients with cardiometabolic diseases to HIIE (≥80% peak power output or ≥85% peak aerobic power, VO2peak). Eleven studies met the inclusion criteria (n = 156; clinically stable, aged 27-66 years), with 13 adverse responses reported (~8% of individuals). The rate of adverse responses is somewhat higher compared to the previously reported risk during moderate-intensity exercise. Caution must be taken when prescribing HIIE to patients with cardiometabolic disease. Patients who wish to perform HIIE should be clinically stable, have had recent exposure to at least regular moderate-intensity exercise, and have appropriate supervision and monitoring during and after the exercise session.

Effectiveness of High-Intensity Interval Training (HIT) and Continuous Endurance Training for VO2max Improvements: A Systematic Review and Meta-Analysis of Controlled Trials

Article

Full-text available

Jul 2015

Background Enhancing cardiovascular fitness can lead to substantial health benefits. High-intensity interval training (HIT) is an efficient way to develop cardiovascular fitness, yet comparisons between this type of training with traditional endurance training are equivocal. Objective Our objective was to meta-analyse the effects of endurance training and HIT on the maximal oxygen consumption (VO2max) of healthy, young to middle-aged adults. Methods Six electronic databases were searched (MEDLINE, PubMed, SPORTDiscus, Web of Science, CINAHL and Google Scholar) for original research articles. A search was conducted and search terms included ‘high intensity’, ‘HIT’, ‘sprint interval training’, ‘endurance training’, ‘peak oxygen uptake’, ‘VO2max’. Inclusion criteria were controlled trials, healthy adults aged 18-45 y, training duration ≥2 weeks, VO2max assessed pre- and post-training. Twenty-eight studies met the inclusion criteria and were included in the meta-analysis. This resulted in 723 participants with a mean ± SD age and initial fitness of 25.1 ± 5 y and 40.8 ± 7.9 mL•kg-1•min-1, respectively. We made probabilistic magnitude-based inferences for meta-analysed effects based on standardized thresholds for small, moderate and large changes (0.2, 0.6 and 1.2, respectively) derived from between-subject standard deviations (SDs) for baseline VO2max. Results The meta-analysed effect of endurance training on VO2max was a possibly large beneficial effect (4.9 mL•kg-1•min-1; 95% confidence limits ±1.4 mL•kg-1•min-1), when compared with no exercise controls. A possibly moderate additional increase was observed for typically younger subjects (2.4 mL•kg-1•min-1; ±2.1 mL•kg-1•min-1) and interventions of longer duration (2.2 mL•kg-1•min-1; ±3.0 mL•kg-1•min-1), and a small additional improvement for subjects with lower baseline fitness (1.4 mL•kg-1•min-1; ±2.0 mL•kg-1•min-1). When compared to no exercise controls, there was likely large beneficial effect of HIT (5.5 mL•kg-1•min-1; ±1.2 mL•kg-1•min-1), with a likely moderate greater additional increase for subjects with lower baseline fitness (3.2 mL•kg-1•min-1; ±1.9 mL•kg-1•min-1) and interventions of longer duration (3.0 mL•kg-1•min-1; ±1.9 mL•kg-1•min-1), and a small lesser effect for typically longer HIT repetitions (-1.8 mL•kg-1•min-1; ±2.7 mL•kg-1•min-1). The modifying effects of age (0.8 mL•kg-1•min-1; ±2.1 mL•kg-1•min-1) and work:rest ratio (0.5 mL•kg-1•min-1; ±1.6 mL•kg-1•min-1) were unclear. When compared to endurance training, there was a possibly small beneficial effect for HIT (1.2 mL•kg-1•min-1; ±0.9 mL•kg-1•min-1) with small additional improvements for typically longer HIT repetitions (2.2 mL•kg-1•min-1; ±2.1 mL•kg-1•min-1), older subjects (1.8 mL•kg-1•min-1; ±1.7 mL•kg-1•min-1), interventions of longer duration (1.7 mL•kg-1•min-1; ±1.7 mL•kg-1•min-1), greater work:rest ratio (1.6 mL•kg-1•min-1; ±1.5 mL•kg-1•min-1) and lower baseline fitness (0.8 mL•kg-1•min-1; ±1.3 mL•kg-1•min-1). Conclusion Endurance training and HIT both elicit large improvements in the VO2max of healthy, young to middle-aged adults with the gains in VO2max being greater following HIT, when compared to endurance training.

High-Intensity Interval Training as an Efficacious Alternative to Moderate-Intensity Continuous Training for Adults with Prediabetes

Article

Full-text available

Mar 2015

Aims: High-intensity interval training (HIIT) leads to improvements in various markers of cardiometabolic health but adherence to HIIT following a supervised laboratory intervention has yet to be tested. We compared self-report and objective measures of physical activity after one month of independent exercise in individuals with prediabetes who were randomized to HIIT (n = 15) or traditional moderate-intensity continuous training (MICT, n = 17). Method: After completing 10 sessions of supervised training participants were asked to perform HIIT or MICT three times per week for four weeks. Results: Individuals in HIIT (89 ± 11%) adhered to their prescribed protocol to a greater extent than individuals in MICT (71 ± 31%) as determined by training logs completed over one-month follow-up (P = 0.05, Cohen's d = 0.75). Minutes spent in vigorous physical activity per week measured by accelerometer were higher in HIIT (24 ± 18) as compared to MICT (11 ± 10) at one-month follow-up (P = 0.049, Cohen's d = 0.92). Cardiorespiratory fitness and systolic blood pressure assessed at one-month follow-up were equally improved (P's < 0.05). Conclusions: This study provides preliminary evidence that individuals with prediabetes can adhere to HIIT over the short-term and do so at a level that is greater than MICT.

Why sprint interval training is inappropriate for a largely sedentary population

Article

Full-text available

Dec 2014

Public health practitioners and researchers in behavioral medicine recognize the need to find effective physical activity interventions and prescriptions to curb the growth in inactivity and prevent chronic illness (Conn et al., 2009; Hagger, 2010; Hardcastle et al., 2012; Katzmarzyk and Lear, 2012). For example, researchers in exercise physiology have focused on the minimal dose of exercise needed to gain favorable physiological adaptations to cardiovascular and metabolic systems (Gibala et al., 2012). Efforts to identify a minimal dose of exercise are linked to the problem of exercise adherence with few people meeting current physical activity guidelines of 30 min per day of moderate intensity exercise. Given that time is the most commonly cited barrier to exercise (Trost et al., 2002; Sequeira et al., 2011), exercise professionals have focused attention on the development of time-efficient exercise interventions (Gibala, 2007). A recent development is the advocacy of Sprint Interval Training (SIT) as a means to attain substantial health benefits with a lower overall exercise volume. SIT is characterized by repeated, brief (4–6 × <30 s), intermittent bursts of all-out exercise, interspersed by periods (approximately 4.5 min) of active or passive recovery (Gibala et al., 2012). Research has consistently demonstrated that participation in SIT results in a host of physiological adaptations including improvements in health and fitness indicators (Burgomaster et al., 2006, 2008; Gibala et al., 2006, 2012; Rossow et al., 2010; Tong et al., 2011). In addition, these improvements have been reported to be equal or superior to traditional continuous aerobic training despite SIT involving a substantially lower total overall training volume (Rossow et al., 2010; Tong et al., 2011; Gibala et al., 2012; Cocks et al., 2013). Consequently, SIT is being advocated as a time-efficient alternative intervention for the achievement of fitness and health benefits through exercise (Gibala, 2007; Whyte et al., 2013).

Three Minutes of All-Out Intermittent Exercise per Week Increases Skeletal Muscle Oxidative Capacity and Improves Cardiometabolic Health

Article

Full-text available

Nov 2014
PLOS ONE

We investigated whether a training protocol that involved 3 min of intense intermittent exercise per week — within a total training time commitment of 30 min including warm up and cool down — could increase skeletal muscle oxidative capacity and markers of health status. Overweight/obese but otherwise healthy men and women (n = 7 each; age = 29±9 y; BMI = 29.8±2.7 kg/m2) performed 18 training sessions over 6 wk on a cycle ergometer. Each session began with a 2 min warm-up at 50 W, followed by 3×20 s “all-out” sprints against 5.0% body mass (mean power output: ∼450–500 W) interspersed with 2 min of recovery at 50 W, followed by a 3 min cool-down at 50 W. Peak oxygen uptake increased by 12% after training (32.6±4.5 vs. 29.1±4.2 ml/kg/min) and resting mean arterial pressure decreased by 7% (78±10 vs. 83±10 mmHg), with no difference between groups (both p<0.01, main effects for time). Skeletal muscle biopsy samples obtained before and 72 h after training revealed increased maximal activity of citrate synthase and protein content of cytochrome oxidase 4 (p<0.01, main effect), while the maximal activity of β-hydroxy acyl CoA dehydrogenase increased in men only (p<0.05). Continuous glucose monitoring measured under standard dietary conditions before and 48–72 h following training revealed lower 24 h average blood glucose concentration in men following training (5.4±0.6 vs. 5.9±0.5 mmol/L, p<0.05), but not women (5.5±0.4 vs. 5.5±0.6 mmol/L). This was associated with a greater increase in GLUT4 protein content in men compared to women (138% vs. 23%, p<0.05). Short-term interval training using a 10 min protocol that involved only 1 min of hard exercise, 3x/wk, stimulated physiological changes linked to improved health in overweight adults. Despite the small sample size, potential sex-specific adaptations were apparent that warrant further investigation.

Effects of high-intensity interval exercise versus continuous moderate-intensity exercise on postprandial glycemic control assessed by continuous glucose monitoring in obese adults

Article

Full-text available

Feb 2014

The purpose of this study was to examine the impact of acute high-intensity interval training (HIIT) compared with continuous moderate-intensity (CMI) exercise on postprandial hyperglycemia in overweight or obese adults. Ten inactive, overweight or obese adults (41 ± 11 yrs, BMI = 36 ± 7 kg/m²) performed an acute bout of HIIT (10 × 1 min at approximately 90% peak heart rate (HRpeak) with 1-min recovery periods) or matched work CMI (30 min at approximately 65% HRpeak) in a randomized, counterbalanced fashion. Exercise was performed 2 h after breakfast, and glucose control was assessed by continuous glucose monitoring under standardized dietary conditions over 24 h. Postprandial glucose (PPG) responses to lunch, dinner, and the following day’s breakfast were analyzed and compared with a no-exercise control day. Exercise did not affect the PPG responses to lunch, but performing both HIIT and CMI in the morning significantly reduced the PPG incremental area under the curve (AUC) following dinner when compared with control (HIIT = 110 ± 35, CMI = 125 ± 34, control = 162 ± 46 mmol/L × 2 h, p < 0.05). The PPG AUC (HIIT = 125 ± 53, CMI = 186 ± 55, control = 194 ± 96 mmol/L × 2 h) and the PPG spike (HIIT = Δ2.1 ± 0.9, CMI = Δ3.0 ± 0.9, control = Δ3.0 ± 1.5 mmol/l) following breakfast on the following day were significantly lower following HIIT compared with both CMI and control (p < 0.05). Absolute AUC and absolute glucose spikes were not different between HIIT, CMI, or control for any meal (p > 0.05 for all). We conclude that a single session of HIIT has greater and more lasting effects on reducing incremental PPG when compared with CMI.

Effects of Low-Volume High-Intensity Interval Training (HIT) on Fitness in Adults: A Meta-Analysis of Controlled and Non-Controlled Trials

Article

Full-text available

Apr 2014
SPORTS MED

Low-volume high-intensity interval training (HIT) appears to be an efficient and practical way to develop physical fitness. Our objective was to estimate meta-analysed mean effects of HIT on aerobic power (maximum oxygen consumption [VO2max] in an incremental test) and sprint fitness (peak and mean power in a 30-s Wingate test). Five databases (PubMed, MEDLINE, Scopus, BIOSIS and Web of Science) were searched for original research articles published up to January 2014. Search terms included 'high intensity', 'HIT', 'sprint', 'fitness' and 'VO2max'. Inclusion criteria were fitness assessed pre- and post-training; training period ≥2 weeks; repetition duration 30-60 s; work/rest ratio <1.0; exercise intensity described as maximal or near maximal; adult subjects aged >18 years. The final data set consisted of 55 estimates from 32 trials for VO2max, 23 estimates from 16 trials for peak sprint power, and 19 estimates from 12 trials for mean sprint power. Effects on fitness were analysed as percentages via log transformation. Standard errors calculated from exact p values (where reported) or imputed from errors of measurement provided appropriate weightings. Fixed effects in the meta-regression model included type of study (controlled, uncontrolled), subject characteristics (sex, training status, baseline fitness) and training parameters (number of training sessions, repetition duration, work/rest ratio). Probabilistic magnitude-based inferences for meta-analysed effects were based on standardized thresholds for small, moderate and large changes (0.2, 0.6 and 1.2, respectively) derived from between-subject standard deviations (SDs) for baseline fitness. A mean low-volume HIT protocol (13 training sessions, 0.16 work/rest ratio) in a controlled trial produced a likely moderate improvement in the VO2max of active non-athletic males (6.2 %; 90 % confidence limits ±3.1 %), when compared with control. There were possibly moderate improvements in the VO2max of sedentary males (10.0 %; ±5.1 %) and active non-athletic females (3.6 %; ±4.3 %) and a likely small increase for sedentary females (7.3 %; ±4.8 %). The effect on the VO2max of athletic males was unclear (2.7 %; ±4.6 %). A possibly moderate additional increase was likely for subjects with a 10 mL·kg(-1)·min(-1) lower baseline VO2max (3.8 %; ±2.5 %), whereas the modifying effects of sex and difference in exercise dose were unclear. The comparison of HIT with traditional endurance training was unclear (-1.6 %; ±4.3 %). Unexplained variation between studies was 2.0 % (SD). Meta-analysed effects of HIT on Wingate peak and mean power were unclear. Low-volume HIT produces moderate improvements in the aerobic power of active non-athletic and sedentary subjects. More studies are needed to resolve the unclear modifying effects of sex and HIT dose on aerobic power and the unclear effects on sprint fitness.

Is high-intensity interval training a time-efficient exercise strategy to improve health and fitness?

Article

Full-text available

Sep 2013

Growing research suggests that high-intensity interval training (HIIT) is a time-efficient exercise strategy to improve cardiorespiratory and metabolic health. “All out” HIIT models such as Wingate-type exercise are particularly effective, but this type of training may not be safe, tolerable or practical for many individuals. Recent studies, however, have revealed the potential for other models of HIIT, which may be more feasible but are still time-efficient, to stimulate adaptations similar to more demanding low-volume HIIT models and high-volume endurance-type training. As little as 3 HIIT sessions per week, involving ≤10 min of intense exercise within a time commitment of ≤30 min per session, including warm-up, recovery between intervals and cool down, has been shown to improve aerobic capacity, skeletal muscle oxidative capacity, exercise tolerance and markers of disease risk after only a few weeks in both healthy individuals and people with cardiometabolic disorders. Additional research is warranted, as studies conducted have been relatively short-term, with a limited number of measurements performed on small groups of subjects. However, given that “lack of time” remains one of the most commonly cited barriers to regular exercise participation, low-volume HIIT is a time-efficient exercise strategy that warrants consideration by health practitioners and fitness professionals.

High Intensity Interval Training in a Real World Setting: A Randomized Controlled Feasibility Study in Overweight Inactive Adults, Measuring Change in Maximal Oxygen Uptake

Article

Full-text available

Jan 2014
PLOS ONE

In research clinic settings, overweight adults undertaking HIIT (high intensity interval training) improve their fitness as effectively as those undertaking conventional walking programs but can do so within a shorter time spent exercising. We undertook a randomized controlled feasibility (pilot) study aimed at extending HIIT into a real world setting by recruiting overweight/obese, inactive adults into a group based activity program, held in a community park. Participants were allocated into one of three groups. The two interventions, aerobic interval training and maximal volitional interval training, were compared with an active control group undertaking walking based exercise. Supervised group sessions (36 per intervention) were held outdoors. Cardiorespiratory fitness was measured using VO2max (maximal oxygen uptake, results expressed in ml/min/kg), before and after the 12 week interventions. On ITT (intention to treat) analyses, baseline (N = 49) and exit (N = 39) [Formula: see text]O2 was 25.3±4.5 and 25.3±3.9, respectively. Participant allocation and baseline/exit VO2max by group was as follows: Aerobic interval training N = 16, 24.2±4.8/25.6±4.8; maximal volitional interval training N = 16, 25.0±2.8/25.2±3.4; walking N = 17, 26.5±5.3/25.2±3.6. The post intervention change in VO2max was +1.01 in the aerobic interval training, -0.06 in the maximal volitional interval training and -1.03 in the walking subgroups. The aerobic interval training subgroup increased VO2max compared to walking (p = 0.03). The actual (observed, rather than prescribed) time spent exercising (minutes per week, ITT analysis) was 74 for aerobic interval training, 45 for maximal volitional interval training and 116 for walking (p = 0.001). On descriptive analysis, the walking subgroup had the fewest adverse events. In contrast to earlier studies, the improvement in cardiorespiratory fitness in a cohort of overweight/obese participants undertaking aerobic interval training in a real world setting was modest. The most likely reason for this finding relates to reduced adherence to the exercise program, when moving beyond the research clinic setting. ACTR.org.au ACTRN12610000295044.

Sprint Interval Training Effects on Aerobic Capacity: A Systematic Review and Meta-Analysis

Article

Full-text available

Oct 2013
SPORTS MED

Sprint interval training (SIT) involving repeated 30-s "all out" efforts have resulted in significantly improved skeletal muscle oxidative capacity, maximal oxygen uptake, and endurance performance. The positive impact of SIT on cardiorespiratory fitness has far-reaching health implications. The objective of this study was to perform a systematic review of the literature and meta-analysis to determine the effects of SIT on aerobic capacity. A search of the literature was conducted using the key words 'sprint interval training', 'high intensity intermittent training/exercise', 'aerobic capacity', and 'maximal oxygen uptake'. Seventeen effects were analyzed from 16 randomized controlled trials of 318 participants. The mean ± standard deviation number of participants was 18.7 ± 5.1. Participant age was 23.5 ± 4.3 years. The effect size calculated for all studies indicates that supramaximal-intensity SIT has a small-to-moderate effect (Cohen's d = 0.32, 95 % CI 0.10-0.55; z = 2.79, P < 0.01) on aerobic capacity with an aggregate improvement of ~3.6 mL·kg(-1)·min(-1) (~8 % increase). The effect is moderate to large in comparison with no-exercise control groups (Cohen's d = 0.69, 95 % CI 0.46-0.93; z = 5.84, P < 0.01) and not different when compared with endurance training control groups (Cohen's d = 0.04, 95 % CI -0.17 to 0.24; z = 0.36, P = 0.72). SIT improves aerobic capacity in healthy, young people. Relative to continuous endurance training of moderate intensity, SIT presents an equally effective alternative with a reduced volume of activity. This evaluation of effects and analysis of moderating variables consolidates the findings of small-sample studies and contributes to the practical application of SIT to improve cardiorespiratory fitness and health.

Estimation of Maximal Oxygen Uptake via Submaximal Exercise Testing in Sports, Clinical, and Home Settings

Article

Full-text available

Jul 2013
SPORTS MED

Assessment of the functional capacity of the cardiovascular system is essential in sports medicine. For athletes, the maximal oxygen uptake [Formula: see text] provides valuable information about their aerobic power. In the clinical setting, the [Formula: see text] provides important diagnostic and prognostic information in several clinical populations, such as patients with coronary artery disease or heart failure. Likewise, [Formula: see text] assessment can be very important to evaluate fitness in asymptomatic adults. Although direct determination of [Formula: see text] is the most accurate method, it requires a maximal level of exertion, which brings a higher risk of adverse events in individuals with an intermediate to high risk of cardiovascular problems. Estimation of [Formula: see text] during submaximal exercise testing can offer a precious alternative. Over the past decades, many protocols have been developed for this purpose. The present review gives an overview of these submaximal protocols and aims to facilitate appropriate test selection in sports, clinical, and home settings. Several factors must be considered when selecting a protocol: (i) The population being tested and its specific needs in terms of safety, supervision, and accuracy and repeatability of the [Formula: see text] estimation. (ii) The parameters upon which the prediction is based (e.g. heart rate, power output, rating of perceived exertion [RPE]), as well as the need for additional clinically relevant parameters (e.g. blood pressure, ECG). (iii) The appropriate test modality that should meet the above-mentioned requirements should also be in line with the functional mobility of the target population, and depends on the available equipment. In the sports setting, high repeatability is crucial to track training-induced seasonal changes. In the clinical setting, special attention must be paid to the test modality, because multiple physiological parameters often need to be measured during test execution. When estimating [Formula: see text], one has to be aware of the effects of medication on heart rate-based submaximal protocols. In the home setting, the submaximal protocols need to be accessible to users with a broad range of characteristics in terms of age, equipment, time available, and an absence of supervision. In this setting, the smart use of sensors such as accelerometers and heart rate monitors will result in protocol-free [Formula: see text] assessments. In conclusion, the need for a low-risk, low-cost, low-supervision, and objective evaluation of [Formula: see text] has brought about the development and the validation of a large number of submaximal exercise tests. It is of paramount importance to use these tests in the right context (sports, clinical, home), to consider the population in which they were developed, and to be aware of their limitations.

Home-Based Aerobic Interval Training Improves Peak Oxygen Uptake Equal to Residential Cardiac Rehabilitation: A Randomized, Controlled Trial

Article

Full-text available

Jul 2012
PLOS ONE

Aerobic capacity, measured as the peak oxygen uptake, is a strong predictor of survival in cardiac patients. Aerobic interval training (AIT), walking/running four times four minutes at 85–95% of peak heart rate, has proven to be effective in increasing peak oxygen uptake in coronary heart disease patients. As some patients do not attend organized rehabilitation programs, home-based exercise should be an alternative. We investigated whether AIT could be performed effectively at home, and compared the effects on peak oxygen uptake with that observed after a standard care, four-week residential rehabilitation. Thirty patients undergoing coronary artery bypass surgery were randomized to residential rehabilitation or home-based AIT. At six months follow-up, peak oxygen uptake increased 4.6 (±2.7) and 3.9 (±3.6) mL·kg−1 min−1 (both p<0.005, non-significant between-group difference) after residential rehabilitation and AIT, respectively. Quality of life increased significantly in both groups, with no statistical significant difference between groups. We found no evidence for a different treatment effect between patients randomized to home-based AIT compared to patients attending organized rehabilitation (95% confidence interval −1.8, 3.5). AIT patients reported good adherence to exercise training. Even though these first data indicate positive effects of home-based AIT in patients undergoing coronary artery bypass surgery, more studies are needed to provide supporting evidence for the application of this rehabilitation strategy. Trial Registration ClinicalTrials.gov NCT00363922

Towards the minimal amount of exercise for improving metabolic health: Beneficial effects of reduced-exertion high-intensity interval training

Article

Full-text available

Nov 2011
EUR J APPL PHYSIOL

High-intensity interval training (HIT) has been proposed as a time-efficient alternative to traditional cardiorespiratory exercise training, but is very fatiguing. In this study, we investigated the effects of a reduced-exertion HIT (REHIT) exercise intervention on insulin sensitivity and aerobic capacity. Twenty-nine healthy but sedentary young men and women were randomly assigned to the REHIT intervention (men, n = 7; women, n = 8) or a control group (men, n = 6; women, n = 8). Subjects assigned to the control groups maintained their normal sedentary lifestyle, whilst subjects in the training groups completed three exercise sessions per week for 6 weeks. The 10-min exercise sessions consisted of low-intensity cycling (60 W) and one (first session) or two (all other sessions) brief 'all-out' sprints (10 s in week 1, 15 s in weeks 2-3 and 20 s in the final 3 weeks). Aerobic capacity ([Formula: see text]) and the glucose and insulin response to a 75-g glucose load (OGTT) were determined before and 3 days after the exercise program. Despite relatively low ratings of perceived exertion (RPE 13 ± 1), insulin sensitivity significantly increased by 28% in the male training group following the REHIT intervention (P < 0.05). [Formula: see text] increased in the male training (+15%) and female training (+12%) groups (P < 0.01). In conclusion we show that a novel, feasible exercise intervention can improve metabolic health and aerobic capacity. REHIT may offer a genuinely time-efficient alternative to HIT and conventional cardiorespiratory exercise training for improving risk factors of T2D.

High-intensity interval training for health and fitness: Can less be more?

Article

Full-text available

Dec 2011
J APPL PHYSIOL

High-intensity interval running is perceived to be more enjoyable than moderate-intensity continuous exercise: Implications for exercise adherence

Article

Full-text available

Feb 2011
J SPORT SCI

The aim of this study was to objectively quantify ratings of perceived enjoyment using the Physical Activity Enjoyment Scale following high-intensity interval running versus moderate-intensity continuous running. Eight recreationally active men performed two running protocols consisting of high-intensity interval running (6 × 3 min at 90% VO(2max) interspersed with 6 × 3 min active recovery at 50% VO(2max) with a 7-min warm-up and cool down at 70% VO(2max)) or 50 min moderate-intensity continuous running at 70% VO(2max). Ratings of perceived enjoyment after exercise were higher (P < 0.05) following interval running compared with continuous running (88 ± 6 vs. 61 ± 12) despite higher (P < 0.05) ratings of perceived exertion (14 ± 1 vs. 13 ± 1). There was no difference (P < 0.05) in average heart rate (88 ± 3 vs. 87 ± 3% maximum heart rate), average VO(2) (71 ± 6 vs. 73 ± 4%VO(2max)), total VO(2) (162 ± 16 vs. 166 ± 27 L) or energy expenditure (811 ± 83 vs. 832 ± 136 kcal) between protocols. The greater enjoyment associated with high-intensity interval running may be relevant for improving exercise adherence, since running is a low-cost exercise intervention requiring no exercise equipment and similar relative exercise intensities have previously induced health benefits in patient populations.

High-Intensity Intermittent Exercise and Fat Loss

Article

Full-text available

Jan 2011
J Obes

Steve Boutcher

The effect of regular aerobic exercise on body fat is negligible; however, other forms of exercise may have a greater impact on body composition. For example, emerging research examining high-intensity intermittent exercise (HIIE) indicates that it may be more effective at reducing subcutaneous and abdominal body fat than other types of exercise. The mechanisms underlying the fat reduction induced by HIIE, however, are undetermined. Regular HIIE has been shown to significantly increase both aerobic and anaerobic fitness. HIIE also significantly lowers insulin resistance and results in a number of skeletal muscle adaptations that result in enhanced skeletal muscle fat oxidation and improved glucose tolerance. This review summarizes the results of HIIE studies on fat loss, fitness, insulin resistance, and skeletal muscle. Possible mechanisms underlying HIIE-induced fat loss and implications for the use of HIIE in the treatment and prevention of obesity are also discussed.

Variability in adherence to an unsupervised exercise prescription in obese women

Article

Full-text available

Jun 2008
INT J OBESITY

Objective: To measure adherence to a specific exercise prescription (1500 kcal week- 1) by objectively quantifying unsupervised exercise energy expenditure (ExEE) in obese women. Design: The 16-week lifestyle intervention consisted of weekly meetings with research staff and promotion of increased ExEE (1500 kcal week- 1) and a decreased dietary intake (- 500 kcal day- 1). Participants: Twenty-nine obese females (body mass index=36.85.0 kg m- 2, body fat=49.63.7% ) from a hospital-based lifestyle intervention were included in the analysis. Measurements: ExEE was estimated and monitored weekly using heart rate monitoring, and body composition was measured before and after the intervention by dual-energy X-ray absorptiometry. Results: Free-living adherence to the exercise prescription was variable and, on average, modest such that 14% achieved 1500 kcal week- 1, and the average weekly ExEE (768 kcal week- 1) represented 51.2% of the total amount prescribed. ExEE was correlated with changes in body weight (r=0.65, P<0.001) and fat mass (r=0.65, P<0.001). Achievement of a 5% weight loss target was dependent on the achievement of an ExEE level of 1000 kcal week- 1 (P<0.001). Exercise 'adherers' (>1000 kcal week- 1) lost more weight (- 9.9 vs - 4.1 kg), more fat mass (- 6.8 vs - 3.0 kg) and more waist circumference (- 9.8 vs - 5.6 cm) when compared to 'non-adherers' (<1000 kcal week- 1). Discussion: Exercise is an integral component of lifestyle interventions aimed at reducing obesity and its complications. However, without accurate and objective measures of ExEE, it is difficult for relationships between exercise and health outcomes to be elucidated. The present study suggests an alternative to self-report to increase the confidence with which conclusions are drawn regarding the role of exercise within lifestyle interventions.

Submaximal Exercise Testing: Clinical Application and Interpretation

Article

Full-text available

Sep 2000

Compared with maximal exercise testing, submaximal exercise testing appears to have greater applicability to physical therapists in their role as clinical exercise specialists. This review contrasts maximal and submaximal exercise testing. Two major categories of submaximal tests (ie, predictive and performance tests) and their relative merits are described. Predictive tests are submaximal tests that are used to predict maximal aerobic capacity. Performance tests involve measuring the responses to standardized physical activities that are typically encountered in everyday life. To maximize the validity and reliability of data obtained from submaximal tests, physical therapists are cautioned to apply the tests selectively based on their indications; to adhere to methods, including the requisite number of practice sessions; and to use measurements such as heart rate, blood pressure, exertion, and pain to evaluate test performance and to safely monitor patients.

Correlates of adults' participation in physical activity: Review and update

Article

Full-text available

Jan 2003

To review and update the evidence relating to the personal, social, and environmental factors associated with physical activity (PA) in adults. Systematic review of the peer-reviewed literature to identify papers published between 1998 and 2000 with PA (and including exercise and exercise adherence). Qualitative reports or case studies were not included. Thirty-eight new studies were located. Most confirmed the existence of factors already known to be correlates of PA. Changes in status were noted in relation to the influence of marital status, obesity, smoking, lack of time, past exercise behavior, and eight environmental variables. New studies were located which focused on previously understudied population groups such as minorities, middle and older aged adults, and the disabled. The newly reported studies tend to take a broader "ecological" approach to understanding the correlates of PA and are more focused on environmental factors. There remains a need to better understand environmental influences and the factors that influence different types of PA. As most of the work in this field still relies on cross-sectional studies, longitudinal and intervention studies will be required if causal relationships are to be inferred.

Cross-Validation of the YMCA Submaximal Cycle Ergometer Test to Predict VO 2 max

Article

Full-text available

Oct 2004

Maximal oxygen uptake (VO2max) is an important indicator of health-risk status, specifically for coronary heart disease (Blair et al., 1989). Direct measurement of VO2max is considered to be the most accurate means of determining cardiovascular fitness level. Typically, this measurement is taken using a progressive exercise test on a treadmill or cycle ergometer. Unfortunately, this test is costly and time consuming and requires a well equipped laboratory, highly trained personnel, and for some populations medical supervision. Therefore, submaximal exercise test protocols that predict VO2max have been developed (Astrand & Rhyming, 1954; Fitchett, 1985). These tests require less equipment, time and are easily administered without highly skilled personnel.

The Effect of Different Types of Monitoring Strategies on Weight Loss: A Randomized Controlled Trial

Article

Jul 2017
OBESITY

Objective: To determine the effectiveness of various monitoring strategies on weight loss, body composition, blood markers, exercise, and psychosocial indices in adults with overweight and obesity following a 12-month weight loss program. Methods: Two hundred fifty adults with BMI ≥ 27 were randomized to brief, monthly, individual consults, daily self-monitoring of weight, self-monitoring of diet using MyFitnessPal, self-monitoring of hunger, or control over 12 months. All groups received diet and exercise advice, and 171 participants (68.4%) remained at 12 months. Results: No significant differences in weight, body composition, blood markers, exercise, or eating behavior were apparent between those in the four monitoring groups and the control condition at 12 months (all P ≥ 0.053). Weight differences between groups ranged from -1.1 kg (-3.8 to 1.6) to 2.2 kg (-1.0 to 5.3). However, brief support and hunger training groups reported significantly lower scores for depression (difference [95% CI]: -3.16 [-5.70 to -0.62] and -3.05 [-5.61 to -0.50], respectively) and anxiety (-1.84, [-3.67 to -0.02]) scores than control participants. Conclusions: Although adding a monitoring strategy to diet and exercise advice did not further increase weight loss, no adverse effects on eating behavior were observed, and some monitoring strategies may even benefit mental health.

The mysterious case of the public health guideline that is (almost) entirely ignored: Call for a research agenda on the causes of the extreme avoidance of physical activity in obesity

Article

Jan 2016
OBES REV

Physical activity and exercise guidelines for weight management call for at least 60 min of daily activity. However, these documents fail to acknowledge that almost no obese adults meet this target and that non-adherence and dropout are even higher among obese individuals than the general population. The reasons for this level of activity avoidance among obese individuals remain poorly understood, and there are no evidence-based methods for addressing the problem. Opinions among exercise scientists are polarized. Some advocate moderate intensity and long duration, whereas others call for high intensity and shorter duration. The latter approach attributes the inactivity and high dropout to limited discretionary time and the slow accrual of visible benefits. However, higher intensity has been associated with non-adherence and dropout, whereas longer duration has not. A conceptual model is then proposed, according to which obesity interacts with intensity, causing physical activity and exercise to be associated with reduced pleasure among obese individuals. We theorize that, in turn, repeated experiences of reduced pleasure lead to avoidance. On this basis, we call for a research agenda aimed at identifying the causes of activity-associated and exercise-associated displeasure in obesity and, by extension, the causes of the extreme physical inactivity among obese individuals.

Long-term Exercise Adherence After High-intensity Interval Training in Cardiac Rehabilitation: A Randomized Study

Article

Feb 2015
Physiother Res Int

Exercise adherence in general is reported to be problematic after cardiac rehabilitation. Additionally, vigorous exercise is associated with impaired exercise adherence. As high-intensity interval training (HIT) is frequently used as a therapy to patients with coronary artery disease in cardiac rehabilitation, the objective was to assess long-term exercise adherence following an HIT cardiac rehabilitation programme. A multicentre randomized study was carried out. Eligible participants were adults who had previously attended a 12-week HIT cardiac rehabilitation programme, as either a home-based or hospital-based HIT (treadmill exercise or group exercise). The primary outcome was change in peak oxygen uptake; secondary outcomes were self-reported and objectively measured physical activity. Out of 83 eligible participants, 76 were available for assessment (68 men/8 women, mean age 59 (8) years) at a one-year follow-up. Peak oxygen uptake was significantly elevated above baseline values, (treadmill exercise: 35.8 (6.4) vs. 37.4 (7.4) ml kg(-1) min(-1) , group exercise: 32.7 (6.5) vs. 34.1 (5.8) ml kg(-1) min(-1) and home-based exercise: 34.5 (4.9) vs. 36.7 (5.8) ml kg(-1) min(-1) at baseline and follow-up, respectively), with no significant differences between groups. The majority of the participants (>90%) met the recommended daily level of 30 minutes of moderate physical activity. The home-based group showed a strong trend towards increased physical activity compared with the hospital-based groups. The results from this study have shown that both home-based and hospital-based HIT in cardiac rehabilitation induce promising long-term exercise adherence, with maintenance of peak oxygen uptake significantly above baseline values at a one-year follow-up. The implication for physiotherapy practice is that HIT in cardiac rehabilitation induces satisfactory long-term exercise adherence. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Leisure-Time Running Reduces All-Cause and Cardiovascular Mortality Risk

Article

Aug 2014
J AM COLL CARDIOL

Background Although running is a popular leisure-time physical activity, little is known about the long-term effects of running on mortality. The dose-response relations between running, as well as the change in running behaviors over time, and mortality remain uncertain. Objectives We examined the associations of running with all-cause and cardiovascular mortality risks in 55,137 adults, 18 to 100 years of age (mean age 44 years). Methods Running was assessed on a medical history questionnaire by leisure-time activity. Results During a mean follow-up of 15 years, 3,413 all-cause and 1,217 cardiovascular deaths occurred. Approximately 24% of adults participated in running in this population. Compared with nonrunners, runners had 30% and 45% lower adjusted risks of all-cause and cardiovascular mortality, respectively, with a 3-year life expectancy benefit. In dose-response analyses, the mortality benefits in runners were similar across quintiles of running time, distance, frequency, amount, and speed, compared with nonrunners. Weekly running even <51 min, <6 miles, 1 to 2 times, <506 metabolic equivalent-minutes, or <6 miles/h was sufficient to reduce risk of mortality, compared with not running. In the analyses of change in running behaviors and mortality, persistent runners had the most significant benefits, with 29% and 50% lower risks of all-cause and cardiovascular mortality, respectively, compared with never-runners. Conclusions Running, even 5 to 10 min/day and at slow speeds <6 miles/h, is associated with markedly reduced risks of death from all causes and cardiovascular disease. This study may motivate healthy but sedentary individuals to begin and continue running for substantial and attainable mortality benefits.

Effects of sprint interval training on VO2max and aerobic exercise performance: A systematic review and meta-analysis

Article

Jul 2013
SCAND J MED SCI SPOR

Recently, several studies have examined whether low-volume sprint interval training (SIT) may improve aerobic and metabolic function. The objective of this study was to systematically review the existing literature regarding the aerobic and metabolic effects of SIT in healthy sedentary or recreationally active adults. A systematic literature search was performed (Bibliotek.dk, SPORTDiscus, Embase, PEDro, SveMed+, and Pubmed). Meta-analytical procedures were applied evaluating effects on maximal oxygen consumption (VO2max ). Nineteen unique studies [four randomized controlled trials (RCTs), nine matched-controlled trials and six noncontrolled studies] were identified, evaluating SIT interventions lasting 2-8 weeks. Strong evidence support improvements of aerobic exercise performance and VO2max following SIT. A meta-analysis across 13 studies evaluating effects of SIT on VO2max showed a weighted mean effects size of g = 0.63 95% CI (0.39; 0.87) and VO2max increases of 4.2-13.4%. Solid evidence support peripheral adaptations known to increase the oxidative potential of the muscle following SIT, whereas evidence regarding central adaptations was limited and equivocal. Some evidence indicated changes in substrate oxidation at rest and during exercise as well as improved glycemic control and insulin sensitivity following SIT. In conclusion, strong evidence support improvement of aerobic exercise performance and VO2max following SIT, which coincides with peripheral muscular adaptations. Future RCTs on long-term SIT and underlying mechanisms are warranted.

Cardiovascular Risk of High- Versus Moderate-Intensity Aerobic Exercise in Coronary Heart Disease Patients

Article

Aug 2012
CIRCULATION

Exercise performed at higher relative intensities has been found to elicit a greater increase in aerobic capacity and greater cardioprotective effects than exercise at moderate intensities. An inverse association has also been detected between the relative intensity of physical activity and the risk of developing coronary heart disease, independent of the total volume of physical activity. Despite that higher levels of physical activity are effective in reducing cardiovascular events, it is also advocated that vigorous exercise could acutely and transiently increase the risk of sudden cardiac death and myocardial infarction in susceptible persons. This issue may affect cardiac rehabilitation. We examined the risk of cardiovascular events during organized high-intensity interval exercise training and moderate-intensity training among 4846 patients with coronary heart disease in 3 Norwegian cardiac rehabilitation centers. In a total of 175 820 exercise training hours during which all patients performed both types of training, we found 1 fatal cardiac arrest during moderate-intensity exercise (129 456 exercise hours) and 2 nonfatal cardiac arrests during high-intensity interval exercise (46 364 exercise hours). There were no myocardial infarctions in the data material. Because the number of high-intensity training hours was 36% of the number of moderate-intensity hours, the rates of complications to the number of patient-exercise hours were 1 per 129 456 hours of moderate-intensity exercise and 1 per 23 182 hours of high-intensity exercise. The results of the current study indicate that the risk of a cardiovascular event is low after both high-intensity exercise and moderate-intensity exercise in a cardiovascular rehabilitation setting. Considering the significant cardiovascular adaptations associated with high-intensity exercise, such exercise should be considered among patients with coronary heart disease.

A Very Brief Measure of the Big-Five Personality Domains

Article

Dec 2003

When time is limited, researchers may be faced with the choice of using an extremely brief measure of the Big-Five personality dimensions or using no measure at all. To meet the need for a very brief measure, 5 and 10-item inventories were developed and evaluated. Although somewhat inferior to standard multi-item instruments, the instruments reached adequate levels in terms of: (a) convergence with widely used Big-Five measures in self, observer, and peer reports, (b) test–retest reliability, (c) patterns of predicted external correlates, and (d) convergence between self and observer ratings. On the basis of these tests, a 10-item measure of the Big-Five dimensions is offered for situations where very short measures are needed, personality is not the primary topic of interest, or researchers can tolerate the somewhat diminished psychometric properties associated with very brief measures.

Physiological adaptations to low-volume, high-intensity interval training in health and disease

Article

Mar 2012
J PHYSIOL-LONDON

Exercise training is a clinically proven, cost-effective, primary intervention that delays and in many cases prevents the health burdens associated with many chronic diseases. However, the precise type and dose of exercise needed to accrue health benefits is a contentious issue with no clear consensus recommendations for the prevention of inactivity-related disorders and chronic diseases. A growing body of evidence demonstrates that high-intensity interval training (HIT) can serve as an effective alternate to traditional endurance-based training, inducing similar or even superior physiological adaptations in healthy individuals and diseased populations, at least when compared on a matched-work basis. While less well studied, low-volume HIT can also stimulate physiological remodelling comparable to moderate-intensity continuous training despite a substantially lower time commitment and reduced total exercise volume. Such findings are important given that 'lack of time' remains the most commonly cited barrier to regular exercise participation. Here we review some of the mechanisms responsible for improved skeletal muscle metabolic control and changes in cardiovascular function in response to low-volume HIT. We also consider the limited evidence regarding the potential application of HIT to people with, or at risk for, cardiometabolic disorders including type 2 diabetes. Finally, we provide insight on the utility of low-volume HIT for improving performance in athletes and highlight suggestions for future research.

Resilience to obesity among socioeconomically disadvantaged women: The READI study

Article

Sep 2011
INT J OBESITY

This cross-sectional study aimed to identify sociodemographic and behavioural characteristics of 'overweight-resilient' women, that is, women who were in a healthy body weight range, despite living in socioeconomically disadvantaged neighbourhoods that place them at increased risk of obesity. The study also aimed to test a comprehensive theoretically derived model of the associations between intrapersonal, social and environmental factors and obesity among this target group. A total of 3235 women aged 18-45 years from 80 urban and rural neighbourhoods throughout Victoria, Australia, participated in the Resilience for Eating and Activity Despite Inequality study. Women reported height, weight, sociodemographic characteristics, leisure-time physical activity, dietary behaviours and a range of theoretically derived cognitive, social and neighbourhood environmental characteristics hypothesized to influence obesity risk. A theoretical model predicting body mass index (BMI) was tested using structural equation models. Women classified as 'resilient' to obesity tended to be younger, born overseas, more highly educated, unmarried and to have higher or undisclosed household incomes. They engaged in more leisure-time physical activity and consumed less fast foods and soft drinks than overweight/obese women. Neighbourhood characteristics, social characteristics and cognitive characteristics all contributed to explaining variation in BMI in the hypothesized directions. These results demonstrate several characteristics of women appearing 'resilient' to obesity, despite their increased risk conferred by residing in socioeconomically disadvantaged neighbourhoods. Acknowledging the cross-sectional study design, the results advance theoretical frameworks aimed at investigating obesity risk by providing evidence in support of a comprehensive model of direct and indirect effects on obesity of neighbourhood, as well as social, cognitive and behavioural characteristics.

Low-Volume Interval Training Improves Muscle Oxidative Capacity in Sedentary Adults

Article

Mar 2011
MED SCI SPORT EXER

High-intensity interval training (HIT) increases skeletal muscle oxidative capacity similar to traditional endurance training, despite a low total exercise volume. Much of this work has focused on young active individuals, and it is unclear whether the results are applicable to older less active populations. In addition, many studies have used "all-out" variable-load exercise interventions (e.g., repeated Wingate tests) that may not be practical for all individuals. We therefore examined the effect of a more practical low-volume submaximal constant-load HIT protocol on skeletal muscle oxidative capacity and insulin sensitivity in middle-aged adults, who may be at a higher risk for inactivity-related disorders. Seven sedentary but otherwise healthy individuals (three women) with a mean ± SD age, body mass index, and peak oxygen uptake (VO(2peak)) of 45 ± 5 yr, 27 ± 5 kg·m(-2), and 30 ± 3 mL·kg(-1)·min(-1) performed six training sessions during 2 wk. Each session involved 10 × 1-min cycling at ∼60% of peak power achieved during a ramp VO(2peak) test (eliciting ∼80%-95% of HR reserve) with 1 min of recovery between intervals. Needle biopsy samples (vastus lateralis) were obtained before training and ∼72 h after the final training session. Muscle oxidative capacity, as reflected by the protein content of citrate synthase and cytochrome c oxidase subunit IV, increased by ∼35% after training. The transcriptional coactivator peroxisome proliferator-activated receptor γ coactivator 1α was increased by ∼56% after training, but the transcriptional corepressor receptor-interacting protein 140 remained unchanged. Glucose transporter protein content increased ∼260%, and insulin sensitivity, on the basis of the insulin sensitivity index homeostasis model assessment, improved by ∼35% after training. Constant-load low-volume HIT may be a practical time-efficient strategy to induce metabolic adaptations that reduce the risk for inactivity-related disorders in previously sedentary middle-aged adults.

Estimation of the Concentration of Low-Density Lipoprotein Cholesterol in Plasma, Without Use of the Preparative Ultracentrifuge

Article

Jul 1972

A method for estimating the cholesterol content of the serum low-density lipoprotein fraction (Sf- 0.20)is presented. The method involves measure- ments of fasting plasma total cholesterol, tri- glyceride, and high-density lipoprotein cholesterol concentrations, none of which requires the use of the preparative ultracentrifuge. Cornparison of this suggested procedure with the more direct procedure, in which the ultracentrifuge is used, yielded correlation coefficients of .94 to .99, de- pending on the patient population compared. Additional Keyph rases hyperlipoproteinemia classifi- cation #{149} determination of plasma total cholesterol, tri- glyceride, high-density lipoprotein cholesterol #{149} beta lipo proteins

A single weekly bout of exercise may reduce cardiovascular mortality: How little pain for cardiac gain? 'The HUNT study, Norway'

Article

Nov 2006

The observation that exercise training reduces cardiovascular mortality is robust and consistent, but the amount and intensity of exercise that is required for risk reduction is not yet resolved. We studied the association between the amount and intensity of exercise and cardiovascular mortality in 27 143 men and 28 929 women who were free from known cardiovascular disease at the beginning of follow-up between 1984 and 1986. The relative risk of death was calculated as the rate of death among participants within a given physical activity category compared with the rate of death in the reference category (no physical activity). We used Cox regression analysis to adjust for age and other potentially confounding factors. After 16 years (SD 4 years) of follow-up, 2946 men (10.8%) and 2486 women (8.6%) had died from ischaemic heart disease or stroke. A single weekly bout of exercise of high intensity reduced the risk of cardiovascular death, both in men [relative risk (RR) 0.61, 95% confidence interval (CI) 0.49-0.75], and women (RR 0.49, 95% CI 0.27-0.89), compared with those who reported no activity. There was no additional benefit from increasing the duration or the number of exercise sessions per week. The risk reduction related to exercise increased with increasing age in men, but not in women. These results challenge the current recommendation that expenditure of at least 1000 kcal per week is required to achieve exercise-induced protection against premature cardiovascular mortality.

Adherence and attrition with intermittent and continuous exercise in overweight women. International Journal of Sports Medicine, 24(6), 459-464

Article

Aug 2003

Few people are active to the levels recommended by Healthy People 2010. Intermittent exercise has been promoted as an exercise prescription which may enable more people to meet recommended guidelines. However, few data are available on intermittent exercise over the long-term. The purpose of the current study was to compare the effects of long-term (72 weeks) continuous (CON) and intermittent (INT) exercise on attrition and adherence in previously sedentary, moderately obese females. Participants were randomized to continuous walking at 60 to 75% of maximum aerobic capacity, 3 days per week, 30 minutes per session, or intermittent exercise for two 15-minute sessions, 5 days per week. Adherence was calculated as the number of sessions completed compared to the number of sessions prescribed. At 12-week intervals, attrition was calculated as the number of participants in the study compared to the total number of participants originally enrolled. For the participants who completed the study, body weight decreased for CON from 80.17 +/- 5.75 kg at baseline to 79.70 +/- 5.40 at 16 months (p < 0.05). For INT, body weight did not change from baseline (85.85 +/- 13.13 kg) to 16 months (85.05 +/- 12.90 kg). By design, INT walked significantly (p < 0.05) further (819 +/- 128 km) compared to CON (527 +/- 46 km). Attrition was 58% for both groups baseline to 72 weeks. However, attrition was greater for CON (38 %) compared to INT (16%) in the first 24 weeks. Adherence was excellent for both groups (> 83%) throughout the study. These results suggest that intermittent and continuous exercise both have considerable attrition rates within 72 weeks of exercise initiation; however, the pattern of attrition differs considerably. That is, it appears that intermittent exercise may reduce attrition in the first 24 weeks of an exercise program; however, attrition does not appear to be different than continuous exercise at 72 weeks.

Long-term exercise adherence after high-intensity interval training in cardiac rehabilitation: a randomized study

Jan 2016
Physiother Res Int
54-64

I L Aamot
T Karlsen
H Dalen
A Stlylen

Aamot IL, Karlsen T, Dalen H, StLylen A. Long-term exercise adherence after high-intensity interval training in cardiac rehabilitation: a randomized study. Physiother Res Int. 2016;21:54-64.

ACSM_s Guidelines for Exercise Testing and Prescription

Jan 2013

American College Of Sports Medicine
L Pescatello
R Arena
D Reibe
P Thompson

American College of Sports Medicine, Pescatello L, Arena R, Reibe D, Thompson P. ACSM_s Guidelines for Exercise Testing and Prescription. 9th ed. Philadelphia: Lippincott Williams & Wilkins; 2013.

HIIT in the Real World: Outcomes from a 12-Month Intervention in Overweight Adults

Abstract

No full-text available

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