VO2max

Time to Differentiate Postactivation “Potentiation” from “Performance Enhancement” in the Strength and Conditioning Community

Olaf Prieske, Martin Behrens, Hélmi Chaabène +2 more · Sports Medicine · 2020 · 144 citations

This meta-analysis and current opinion article argues that the term "postactivation potentiation" (PAP) has been misapplied in the strength and conditioning literature, and proposes a new term — "postactivation performance enhancement" (PAPE) — to describe the acute improvement in voluntary performance (e.g., jump height, sprint speed) after a heavy conditioning contraction, reserving "PAP" strictly for the physiological mechanism measured via electrically-evoked twitch force, which matters because conflating the two leads to inconsistent study results and poor translation to real-world training.

High-Intensity Interval Training in Patients With Heart Failure With Reduced Ejection Fraction

Øyvind Ellingsen, Martin Halle, Viviane M. Conraads +25 more · Circulation · 2017 · 405 citations

High-intensity interval training (HIIT) was not superior to moderate continuous training (MCT) for improving heart structure or exercise capacity in heart failure patients, and neither group maintained their modest gains after one year — meaning that for most people, the simpler, more sustainable moderate exercise is just as effective as the trendy HIIT approach.

Precision exercise medicine: understanding exercise response variability

Robert Ross, Bret H. Goodpaster, Lauren G. Koch +13 more · British Journal of Sports Medicine · 2019 · 260 citations

When people follow the same exercise programme, their improvement in cardiorespiratory fitness varies enormously — from zero gain to a 50% increase — and about 50% of that variability is explained by genetics, meaning you cannot predict your own response from someone else's results.

High Intensity Interval- vs Moderate Intensity- Training for Improving Cardiometabolic Health in Overweight or Obese Males: A Randomized Controlled Trial

Gordon Fisher, Andrew W. Brown, Michelle M Bohan Brown +7 more · PLoS ONE · 2015 · 238 citations

Six weeks of either high intensity interval training (HIIT, ~1 hour/week) or moderate intensity training (MIT, ~5 hours/week) produced similar improvements in body fat percentage, insulin sensitivity, and blood lipids in sedentary overweight young men, but MIT was significantly better at improving cardiovascular fitness (VO2peak increased 11.1% vs 2.83%).

Comparison of High-Intensity Interval Training and Moderate-to-Vigorous Continuous Training for Cardiometabolic Health and Exercise Enjoyment in Obese Young Women: A Randomized Controlled Trial

Zhaowei Kong, Xitao Fan, Shengyan Sun +3 more · PLoS ONE · 2016 · 184 citations

Both high-intensity interval training (HIIT) and moderate-to-vigorous continuous training (MVCT) improved cardiorespiratory fitness by about 9–10% over 5 weeks in obese young women, but HIIT was more enjoyable and required half the exercise time (20 minutes vs. 40 minutes per session), making it a time-efficient alternative for people who struggle with exercise adherence.

Nicotinamide mononucleotide supplementation enhances aerobic capacity in amateur runners: a randomized, double-blind study

Bagen Liao, Yunlong Zhao, Dan Wang +3 more · Journal of the International Society of Sports Nutrition · 2021 · 89 citations

Taking 600–1200 mg/day of nicotinamide mononucleotide (NMN) for six weeks, combined with regular endurance training, improved how efficiently amateur runners used oxygen at sub-maximal exercise intensities, but did not increase their maximum oxygen uptake (VO2max).

Maximum Oxygen Uptake of Male Soccer Players According to their Competitive Level, Playing Position and Age Group: Implication from a Network Meta-Analysis

Maamer Slimani, Hela Znazen, Bianca Miarka +1 more · Journal of Human Kinetics · 2019 · 91 citations

Higher-level male soccer players have a moderately larger maximum oxygen uptake (VO₂max) than lower-level players (effect size = 0.58), goalkeepers have substantially lower VO₂max than defenders and midfielders (effect sizes ~1.3–1.4), and VO₂max increases steadily with age from under-10 to under-23, meaning that if you want to improve your soccer performance, boosting your aerobic capacity is a well-supported target, but you must account for your position and age group.

The effectiveness of aerobic and muscle strength training in patients receiving hemodialysis and EPO: A randomized controlled trial

Vincent DePaul, Julie Moreland, Tom Eager +1 more · American Journal of Kidney Diseases · 2002 · 159 citations

Effect of Caloric Restriction or Aerobic Exercise Training on Peak Oxygen Consumption and Quality of Life in Obese Older Patients With Heart Failure With Preserved Ejection Fraction

Dalane W. Kitzman, Peter H. Brubaker, Timothy M. Morgan +5 more · JAMA · 2016 · 866 citations

IMPORTANCE: More than 80% of patients with heart failure with preserved ejection fraction (HFPEF), the most common form of heart failure among older persons, are overweight or obese. Exercise intolerance is the primary symptom of chronic HFPEF and a major determinant of reduced quality of life (QOL). OBJECTIVE: To determine whether caloric restriction (diet) or aerobic exercise training (exercise) improves exercise capacity and QOL in obese older patients with HFPEF. DESIGN, SETTING, AND PARTICIPANTS: Randomized, attention-controlled, 2 × 2 factorial trial conducted from February 2009 through November 2014 in an urban academic medical center. Of 577 initially screened participants, 100 older obese participants (mean [SD]: age, 67 years [5]; body mass index, 39.3 [5.6]) with chronic, stable HFPEF were enrolled (366 excluded by inclusion and exclusion criteria, 31 for other reasons, and 80 declined participation). INTERVENTIONS: Twenty weeks of diet, exercise, or both; attention control consisted of telephone calls every 2 weeks. MAIN OUTCOMES AND MEASURES: Exercise capacity measured as peak oxygen consumption (V̇O2, mL/kg/min; co-primary outcome) and QOL measured by the Minnesota Living with Heart Failure (MLHF) Questionnaire (score range: 0-105, higher scores indicate worse heart failure-related QOL; co-primary outcome). RESULTS: Of the 100 enrolled participants, 26 participants were randomized to exercise; 24 to diet; 25 to exercise + diet; 25 to control. Of these, 92 participants completed the trial. Exercise attendance was 84% (SD, 14%) and diet adherence was 99% (SD, 1%). By main effects analysis, peak V̇O2 was increased significantly by both interventions: exercise, 1.2 mL/kg body mass/min (95% CI, 0.7 to 1.7), P < .001; diet, 1.3 mL/kg body mass/min (95% CI, 0.8 to 1.8), P < .001. The combination of exercise + diet was additive (complementary) for peak V̇O2 (joint effect, 2.5 mL/kg/min). There was no statistically significant change in MLHF total score with exercise and with diet (main effect: exercise, -1 unit [95% CI, -8 to 5], P = .70; diet, -6 units [95% CI, -12 to 1], P = .08). The change in peak V̇O2 was positively correlated with the change in percent lean body mass (r = 0.32; P = .003) and the change in thigh muscle:intermuscular fat ratio (r = 0.27; P = .02). There were no study-related serious adverse events. Body weight decreased by 7% (7 kg [SD, 1]) in the diet group, 3% (4 kg [SD, 1]) in the exercise group, 10% (11 kg [SD, 1] in the exercise + diet group, and 1% (1 kg [SD, 1]) in the control group. CONCLUSIONS AND RELEVANCE: Among obese older patients with clinically stable HFPEF, caloric restriction or aerobic exercise training increased peak V̇O2, and the effects may be additive. Neither intervention had a significant effect on quality of life as measured by the MLHF Questionnaire. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00959660.

Sedentary Lifestyle, Poor Cardiorespiratory Fitness, and the Metabolic Syndrome

Timo A. Lakka, David E. Laaksonen, Hanna-Maaria Lakka +4 more · Medicine & Science in Sports & Exercise · 2003 · 471 citations

PURPOSE: The cross-sectional associations of leisure-time physical activity (LTPA) and cardiorespiratory fitness with the metabolic syndrome (MS) were investigated in a population-based sample of 1069 middle-aged men without diabetes, cardiovascular disease, or cancer. METHODS: LTPA was assessed using a detailed quantitative questionnaire. Maximal oxygen uptake VO(2max) and core and related features of the MS were determined. A modified World Health Organization definition of the MS and factor analysis were used. RESULTS: Men who engaged in at least moderate-intensity (>or=4.5 metabolic equivalents) LTPA <1.0 h.wk-1 were 60% more likely to have the MS than those engaging in >or= 3.0 h.wk-1 even after adjustment for confounders. Low-intensity (<4.5 metabolic equivalents) LTPA was not associated with the metabolic syndrome. Men with a VO(2max) <29.1 mL x kg-1 x min-1 were almost seven times more likely to have the MS than those with a VO(2max) >or=35.5 mL.kg-1.min-1 even after adjusting for confounders. In first-order factor analysis using a promax rotation, the principal factor explained 20% of total variance and had heavy loadings for VO(2max) (-0.57) and at least moderate-intensity LTPA (-0.44), and moderate or heavy loadings for the main components of the MS. The second-order factor analysis generated a principal factor that was strongly loaded on by the main components of the MS and VO(2max) (-0.50) but not LTPA. CONCLUSION: A sedentary lifestyle and especially poor cardiorespiratory fitness are not only associated with the MS but could also be considered features of the MS. Measurement of VO(2max) in sedentary men with risk factors may provide an efficient means for targeting individuals who would benefit from interventions to prevent the MS and its consequences.

Effect of Wearing the Elevation Training Mask on Aerobic Capacity, Lung Function, and Hematological Variables.

John P. Porcari, Lauren Probst, Karlei Forrester +4 more · PubMed · 2016 · 62 citations

Altitude training and respiratory muscle training (RMT) have been reported to improve performance in elite and well-trained athletes. Several devices (altitude and RMT) have been developed to help athletes gain the competitive edge. The Elevation Training Mask 2.0 (ETM) purportedly simulates altitude training and has been suggested to increase aerobic capacity (VO2max), endurance performance, and lung function. Twenty-four moderately trained subjects completed 6 weeks of high-intensity cycle ergometer training. Subjects were randomized into a mask (n = 12) or control (n = 12) group. Pre and post-training tests included VO2max, pulmonary function, maximal inspiration pressure, hemoglobin and hematocrit. No significant differences were found in pulmonary function or hematological variables between or within groups. There was a significant improvement in VO2max and PPO in both the control (13.5% and 9.9%) and mask (16.5% and 13.6%) groups. There was no difference in the magnitude of improvement between groups. Only the mask group had significant improvements in ventilatory threshold (VT) (13.9%), power output (PO) at VT (19.3%), respiratory compensation threshold (RCT) (10.2%), and PO at RCT (16.4%) from pre to post-testing. The trends for improvements in VT and PO at VT between groups were similar to improvements in RCT and PO at RCT, but did not reach statistical significance (VT p = 0.06, PO at VT p = 0.170). Wearing the ETM while participating in a 6-week high-intensity cycle ergometer training program does not appear to act as a simulator of altitude, but more like a respiratory muscle training device. Wearing the ETM may improve specific markers of endurance performance beyond the improvements seen with interval training alone. Key pointsWearing the ETM during a 6-week high-intensity cycle ergometer training program may improve performance variables, such as VO2max, PPO, VT, PO at VT, RCT and PO at RCT.Wearing the ETM did not improve lung function, inspiratory muscle strength, or stimulate changes in hemoglobin or hematocrit levels.The ETM does not simulate altitude, but works more like an respiratory training device.

Aerobic Interval Training Versus Continuous Moderate Exercise as a Treatment for the Metabolic Syndrome

Arnt Erik Tjønna, Sang Jun Lee, Øivind Rognmo +10 more · Circulation · 2008 · 1,129 citations

BACKGROUND: Individuals with the metabolic syndrome are 3 times more likely to die of heart disease than healthy counterparts. Exercise training reduces several of the symptoms of the syndrome, but the exercise intensity that yields the maximal beneficial adaptations is in dispute. We compared moderate and high exercise intensity with regard to variables associated with cardiovascular function and prognosis in patients with the metabolic syndrome. METHODS AND RESULTS: Thirty-two metabolic syndrome patients (age, 52.3+/-3.7 years; maximal oxygen uptake [o(2)max], 34 mL x kg(-1) x min(-1)) were randomized to equal volumes of either moderate continuous moderate exercise (CME; 70% of highest measured heart rate [Hfmax]) or aerobic interval training (AIT; 90% of Hfmax) 3 times a week for 16 weeks or to a control group. o(2)max increased more after AIT than CME (35% versus 16%; P<0.01) and was associated with removal of more risk factors that constitute the metabolic syndrome (number of factors: AIT, 5.9 before versus 4.0 after; P<0.01; CME, 5.7 before versus 5.0 after; group difference, P<0.05). AIT was superior to CME in enhancing endothelial function (9% versus 5%; P<0.001), insulin signaling in fat and skeletal muscle, skeletal muscle biogenesis, and excitation-contraction coupling and in reducing blood glucose and lipogenesis in adipose tissue. The 2 exercise programs were equally effective at lowering mean arterial blood pressure and reducing body weight (-2.3 and -3.6 kg in AIT and CME, respectively) and fat. CONCLUSIONS: Exercise intensity was an important factor for improving aerobic capacity and reversing the risk factors of the metabolic syndrome. These findings may have important implications for exercise training in rehabilitation programs and future studies.

Exercise and Arterial Stiffness in the Elderly: A Combined Cross-Sectional and Randomized Controlled Trial (EXAMIN AGE)

Arne Deiseroth, Lukas Streese, Sabrina Köchli +4 more · Frontiers in Physiology · 2019 · 37 citations

Long-term physical activity is strongly associated with lower arterial stiffness in older adults, but 12 weeks of high-intensity interval training (HIIT) did not reduce arterial stiffness on its own — only when it also lowered blood pressure did stiffness improve, meaning exercise may need to hit a blood pressure threshold to reverse age-related hardening of the arteries.

Aerobic exercise intensity assessment and prescription in cardiac rehabilitation: a joint position statement of the European Association for Cardiovascular Prevention and Rehabilitation, the American Association of Cardiovascular and Pulmonary Rehabilitation and the Canadian Association of Cardiac Rehabilitation

Alessandro Mezzani, Larry F. Hamm, Andrew M. Jones +5 more · European Journal of Preventive Cardiology · 2012 · 545 citations

Aerobic exercise intensity prescription is a key issue in cardiac rehabilitation, being directly linked to both the amount of improvement in exercise capacity and the risk of adverse events during exercise. This joint position statement aims to provide professionals with up-to-date information regarding the identification of different exercise intensity domains, the methods of direct and indirect determination of exercise intensity for both continuous and interval aerobic training, the effects of the use of different exercise protocols on exercise intensity prescription and the indications for recommended exercise training prescription in specific cardiac patients' groups. The importance of functional evaluation through exercise testing prior to starting an aerobic training program is strongly emphasized, and ramp incremental cardiopulmonary exercise test, when available, is proposed as the gold standard for a physiologically comprehensive exercise intensity assessment and prescription. This may allow a shift from a 'range-based' to a 'threshold-based' aerobic exercise intensity prescription, which, combined with thorough clinical evaluation and exercise-related risk assessment, could maximize the benefits obtainable by the use of aerobic exercise training in cardiac rehabilitation.

Efficacy of Feedback-Controlled Robotics-Assisted Treadmill Exercise to Improve Cardiovascular Fitness Early After Stroke

Oliver Stoller, Eling D. de Bruin, Matthias Schindelholz +3 more · Journal of Neurologic Physical Therapy · 2015 · 36 citations

BACKGROUND AND PURPOSE: Cardiovascular fitness is greatly reduced after stroke. Although individuals with mild to moderate impairments benefit from conventional cardiovascular exercise interventions, there is a lack of effective approaches for persons with severely impaired physical function. This randomized controlled pilot trial investigated efficacy and feasibility of feedback-controlled robotics-assisted treadmill exercise (FC-RATE) for cardiovascular rehabilitation in persons with severe impairments early after stroke. METHODS: Twenty individuals (age 61 ± 11 years; 52 ± 31 days poststroke) with severe motor limitations (Functional Ambulation Classification 0-2) were recruited for FC-RATE or conventional robotics-assisted treadmill exercise (RATE) (4 weeks, 3 × 30-minute sessions/wk). Outcome measures focused on peak cardiopulmonary performance parameters, training intensity, and feasibility, with examiners blinded to allocation. RESULTS: All 14 allocated participants (70% of recruited) completed the intervention (7/group, withdrawals unrelated to intervention), without serious adverse events occurring. Cardiovascular fitness increased significantly in both groups, with peak oxygen uptake increasing from 14.6 to 17.7 mL · kg · min (+17.8%) after 4 weeks (45.8%-55.7% of predicted maximal aerobic capacity; time effect P = 0.01; no group-time interaction). Training intensity (% heart rate reserve) was significantly higher for FC-RATE (40% ± 3%) than for conventional RATE (14% ± 2%) (P = 0.001). DISCUSSION AND CONCLUSIONS: Substantive overall increases in the main cardiopulmonary performance parameters were observed, but there were no significant between-group differences when comparing FC-RATE and conventional RATE. Feedback-controlled robotics-assisted treadmill exercise significantly increased exercise intensity, but recommended intensity levels for cardiovascular training were not consistently achieved. Future research should focus on appropriate algorithms within advanced robotic systems to promote optimal cardiovascular stress.Video abstract available for more insights from the authors (Supplemental Digital Content 1, http://links.lww.com/JNPT/A107).

Twelve Weeks of Sprint Interval Training Improves Indices of Cardiometabolic Health Similar to Traditional Endurance Training despite a Five-Fold Lower Exercise Volume and Time Commitment

Jenna B. Gillen, Brian J. Martin, Martin J. MacInnis +3 more · PLoS ONE · 2016 · 341 citations

AIMS: We investigated whether sprint interval training (SIT) was a time-efficient exercise strategy to improve insulin sensitivity and other indices of cardiometabolic health to the same extent as traditional moderate-intensity continuous training (MICT). SIT involved 1 minute of intense exercise within a 10-minute time commitment, whereas MICT involved 50 minutes of continuous exercise per session. METHODS: Sedentary men (27±8y; BMI = 26±6kg/m2) performed three weekly sessions of SIT (n = 9) or MICT (n = 10) for 12 weeks or served as non-training controls (n = 6). SIT involved 3x20-second 'all-out' cycle sprints (~500W) interspersed with 2 minutes of cycling at 50W, whereas MICT involved 45 minutes of continuous cycling at ~70% maximal heart rate (~110W). Both protocols involved a 2-minute warm-up and 3-minute cool-down at 50W. RESULTS: Peak oxygen uptake increased after training by 19% in both groups (SIT: 32±7 to 38±8; MICT: 34±6 to 40±8ml/kg/min; p<0.001 for both). Insulin sensitivity index (CSI), determined by intravenous glucose tolerance tests performed before and 72 hours after training, increased similarly after SIT (4.9±2.5 to 7.5±4.7, p = 0.002) and MICT (5.0±3.3 to 6.7±5.0 x 10-4 min-1 [μU/mL]-1, p = 0.013) (p<0.05). Skeletal muscle mitochondrial content also increased similarly after SIT and MICT, as primarily reflected by the maximal activity of citrate synthase (CS; P<0.001). The corresponding changes in the control group were small for VO2peak (p = 0.99), CSI (p = 0.63) and CS (p = 0.97). CONCLUSIONS: Twelve weeks of brief intense interval exercise improved indices of cardiometabolic health to the same extent as traditional endurance training in sedentary men, despite a five-fold lower exercise volume and time commitment.

Effects of a Supervised Home-Based Aerobic and Progressive Resistance Training Regimen in Women Infected With Human Immunodeficiency Virus

Sara Dolan, Walter R. Frontera, Jamie Librizzi +6 more · Archives of Internal Medicine · 2006 · 162 citations

BACKGROUND: Women infected with human immunodeficiency virus (HIV) increasingly demonstrate abnormalities in fat distribution and metabolism; however, the effects of a home-based exercise regimen in this group have not been investigated. METHODS: We conducted a 16-week randomized intervention study of a supervised home-based progressive resistance training and aerobic exercise program in 40 HIV-infected women with increased waist-hip ratio and self-reported fat redistribution. Cross-sectional muscle area and muscle attenuation were measured by computed tomography. Cardiorespiratory fitness was determined by calculated maximum oxygen consumption (VO2max) and strength by 1-repetition maximum. RESULTS: Cardiorespiratory fitness (VO2max) was markedly lower at baseline (median [95% confidence interval], 15.4 [8.3-25.2] mL x kg(-1) x min(-1)) than reported values for healthy female subjects (26-35 mL x kg(-1) x min(-1)). Subjects randomized to exercise had significant improvement in mean +/- SEM VO2max (1.5 +/- 0.8 vs -2.5 +/- 1.6 mL x kg(-1) x min(-1); P<.001) and endurance (1.0 +/- 0.3 vs -0.6 +/- 0.3 minute; P<.001). Strength increased at the knee extensors, pectoralis, knee flexors, shoulder abductors, ankle plantar flexors, and elbow flexors (all P<.001). Total muscle area (6 +/- 1 vs 2 +/- 1 cm2; P = .02) and attenuation (2 +/- 1 vs -1 +/- 1 Hounsfield unit; P = .03) increased in the exercise group. No significant difference was seen in lipid levels, blood pressure, or abdominal visceral fat between the groups, but subjects randomized to exercise reported improved energy and appearance. CONCLUSIONS: A 16-week, supervised, home-based exercise regimen improved measures of physical fitness in HIV-infected women. The effects on strength were most significant, but improvements in cardiorespiratory fitness, endurance, and body composition were also seen.

Effect of Inorganic Nitrite vs Placebo on Exercise Capacity Among Patients With Heart Failure With Preserved Ejection Fraction

Barry A. Borlaug, Kevin J. Anstrom, Gregory D. Lewis +18 more · JAMA · 2018 · 254 citations

Importance: There are few effective treatments for heart failure with preserved ejection fraction (HFpEF). Short-term administration of inorganic nitrite or nitrate preparations has been shown to enhance nitric oxide signaling, which may improve aerobic capacity in HFpEF. Objective: To determine the effect of 4 weeks' administration of inhaled, nebulized inorganic nitrite on exercise capacity in HFpEF. Design, Setting, and Participants: Multicenter, double-blind, placebo-controlled, 2-treatment, crossover trial of 105 patients with HFpEF. Participants were enrolled from July 22, 2016, to September 12, 2017, at 17 US sites, with final date of follow-up of January 2, 2018. Interventions: Inorganic nitrite or placebo administered via micronebulizer device. During each 6-week phase of the crossover study, participants received no study drug for 2 weeks (baseline/washout) followed by study drug (nitrite or placebo) at 46 mg 3 times a day for 1 week followed by 80 mg 3 times a day for 3 weeks. Main Outcomes and Measures: The primary end point was peak oxygen consumption (mL/kg/min). Secondary end points included daily activity levels assessed by accelerometry, health status as assessed by the Kansas City Cardiomyopathy Questionnaire (score range, 0-100, with higher scores reflecting better quality of life), functional class, cardiac filling pressures assessed by echocardiography, N-terminal fragment of the prohormone brain natriuretic peptide levels, other exercise indices, adverse events, and tolerability. Outcomes were assessed after treatment for 4 weeks. Results: Among 105 patients who were randomized (median age, 68 years; 56% women), 98 (93%) completed the trial. During the nitrite phase, there was no significant difference in mean peak oxygen consumption as compared with the placebo phase (13.5 vs 13.7 mL/kg/min; difference, -0.20 [95% CI, -0.56 to 0.16]; P = .27). There were no significant between-treatment phase differences in daily activity levels (5497 vs 5503 accelerometry units; difference, -15 [95% CI, -264 to 234]; P = .91), Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (62.6 vs 61.9; difference, 1.1 [95% CI, -1.4 to 3.5]; P = .39), functional class (2.5 vs 2.5; difference, 0.1 [95% CI, -0.1 to 0.2]; P = .43), echocardiographic E/e' ratio (16.4 vs 16.6; difference, 0.1 [95% CI, -1.2 to 1.3]; P = .93), or N-terminal fragment of the prohormone brain natriuretic peptide levels (520 vs 533 pg/mL; difference, 11 [95% CI, -53 to 75]; P = .74). Worsening heart failure occurred in 3 participants (2.9%) during the nitrite phase and 8 (7.6%) during the placebo phase. Conclusions and Relevance: Among patients with HFpEF, administration of inhaled inorganic nitrite for 4 weeks, compared with placebo, did not result in significant improvement in exercise capacity. Trial Registration: ClinicalTrials.gov Identifier: NCT02742129.

Effects of Circuit Weight-Interval Training on Physical Fitness, Cardiac Autonomic Control, and Quality of Life in Sedentary Workers

S. A. Oliveira, Daniel Boullosa, Maria Lua Marques de Mendonça +8 more · International Journal of Environmental Research and Public Health · 2021 · 14 citations

Sedentary behaviors, those that involve sitting and low levels of energy expenditure, have been associated with several adverse cardiometabolic effects. This study evaluated the chronic effects of a combined circuit weight interval training (CWIT) on physical fitness, quality of life, and heart rate variability (HRV), and compared the effects of CWIT-induced autonomic adaptations on different postures in adult sedentary workers. Twenty-seven sedentary workers (age 36.9 ± 9.2 years old, 13 men and 14 women) were divided into two groups: control, who continued their sedentary behavior, and experimental, who were submitted to a CWIT for 12 weeks, completing two ~40 min sessions per week. Monitoring of 8th, 16th, and 24th sessions revealed a moderate training load during sessions. Participants exhibited an improved aerobic capacity (VO2max, 34.03 ± 5.36 vs. 36.45 ± 6.05 mL/kg/min, p &lt; 0.05) and flexibility (22.6 ± 11.4 vs. 25.3 ± 10.1 cm, p &lt; 0.05) after the training period. In addition, they showed greater quality of life scores. However, the CWIT did not change body composition. Interestingly, more HRV parameters were improved in the seated position. The CWIT used in the current study was associated with improvements in several fitness and quality of life parameters, as well as in cardiac autonomic control of HR in adult sedentary workers. Examination of different body positions when evaluating changes in HRV appears to be a relevant aspect to be considered in further studies. Future randomized controlled trials (RCTs) with larger samples of both sexes should confirm these promising results.

Does Aerobic Exercise Influence Intrinsic Brain Activity? An Aerobic Exercise Intervention among Healthy Old Adults

Pär Flodin, Lars Jonasson, Katrine Riklund +2 more · Frontiers in Aging Neuroscience · 2017 · 71 citations

Previous studies have indicated that aerobic exercise could reduce age related decline in cognition and brain functioning. Here we investigated the effects of aerobic exercise on intrinsic brain activity. Sixty sedentary healthy males and females (64-78yrs) were randomized into either an aerobic exercise group or an active control group. Both groups recieved supervised training, three days a week for six months. Multimodal brain imaging data was acquired before and after the intervention, including 10 min of resting state brain functional magnetic resonance imaging (rs-fMRI) and arterial spin labeling (ASL). Additionally, a comprehensive battery of cognitive tasks assessing e.g. executive function and episodic memory was administered. Both the aerobic and the control group improved in aerobic capacity (VO2-peak) over six months, but a significant group by time interaction confirmed that the aerobic group improved more. Contrary to our hypothesis, we did not observe any significant group by time interactions with regard to any measure of intrinsic activity. To further probe putative relationships between fitness and brain activity, we performed post-hoc analyses disregarding group belongings. At baseline, VO2-peak was negativly related to BOLD-signal fluctuations (BOLDSTD) in mid temporal areas. Over six months, improvements in aerobic capacity were associated with decreased connectivity between left hippocampus and contralateral precentral gyrus, and positively to connectivity between right mid-temporal areas and frontal and parietal regions. Independent component analysis (ICA) identified a VO2-related increase in coupling between the default mode network (DMN) and left orbitofrontal cortex, as well as a decreased connectivity between the sensorimotor network and thalamus. Extensive exploratory data analyses of global efficiency, connectome wide multivariate pattern analysis (connectome-MVPA), as well as ASL, did not reveal any relationships between aerobic fitness and intrinsic brain activity. Moreover, fitness-predicted changes in functional connectivity did not relate to changes in cognition, which is likely due to absent cross-sectional or longitudinal relationships between VO2-peak and cognition. We conclude that the aerobic exercise intervention had limited influence on patterns of intrinsic brain activity, although post-hoc analyses indicated that individual changes in aerobic capacity preferentially affected mid-temporal brain areas.

Inter-Individual Variability in the Adaptive Responses to Endurance and Sprint Interval Training: A Randomized Crossover Study

Jacob T. Bonafiglia, Mario Rotundo, Jonathan Whittall +3 more · PLoS ONE · 2016 · 169 citations

The current study examined the adaptive response to both endurance (END) and sprint interval training (SIT) in a group of twenty-one recreationally active adults. All participants completed three weeks (four days/ week) of both END (30 minutes at ~65% VO2peak work rate (WR) and SIT (eight, 20-second intervals at ~170% VO2peak WR separated by 10 seconds of active rest) following a randomized crossover study design with a three-month washout period between training interventions. While a main effect of training was observed for VO2peak, lactate threshold, and submaximal heart rate (HR), considerable variability was observed in the individual responses to both END and SIT. No significant positive relationships were observed between END and SIT for individual changes in any variable. Non-responses were determined using two times the typical error (TE) of measurement for VO2peak (0.107 L/min), lactate threshold (15.7 W), and submaximal HR (10.7bpm). Non-responders in VO2peak, lactate threshold, and submaximal HR were observed following both END and SIT, however, the individual patterns of response differed following END and SIT. Interestingly, all individuals responded in at least one variable when exposed to both END and SIT. These results suggest that the individual response to exercise training is highly variable following different training protocols and that the incidence of non-response to exercise training may be reduced by changing the training stimulus for non-responders to three weeks of END or SIT.

Low- and High-Volume of Intensive Endurance Training Significantly Improves Maximal Oxygen Uptake after 10-Weeks of Training in Healthy Men

Arnt Erik Tjønna, Ingeborg Megaard Leinan, Anette Thoresen Bartnes +4 more · PLoS ONE · 2013 · 165 citations

UNLABELLED: Regular exercise training improves maximal oxygen uptake (VO2max), but the optimal intensity and volume necessary to obtain maximal benefit remains to be defined. A growing body of evidence suggests that exercise training with low-volume but high-intensity may be a time-efficient means to achieve health benefits. In the present study, we measured changes in VO2max and traditional cardiovascular risk factors after a 10 wk. training protocol that involved three weekly high-intensity interval sessions. One group followed a protocol which consisted of 4×4 min at 90% of maximal heart rate (HRmax) interspersed with 3 min active recovery at 70% HRmax (4-AIT), the other group performed a single bout protocol that consisted of 1×4 min at 90% HRmax (1-AIT). Twenty-six inactive but otherwise healthy overweight men (BMI: 25-30, age: 35-45 y) were randomized to either 1-AIT (n = 11) or 4-AIT (n = 13). After training, VO2max increased by 10% (∼5.0 mL⋅kg(-1)⋅min(-1)) and 13% (∼6.5 mL⋅kg(-1)⋅min(-1)) after 1-AIT and 4-AIT, respectively (group difference, p = 0.08). Oxygen cost during running at a sub-maximal workload was reduced by 14% and 13% after 1-AIT and 4-AIT, respectively. Systolic blood pressure decreased by 7.1 and 2.6 mmHg after 1-AIT and 4-AIT respectively, while diastolic pressure decreased by 7.7 and 6.1 mmHg (group difference, p = 0.84). Both groups had a similar ∼5% decrease in fasting glucose. Body fat, total cholesterol, LDL-cholesterol, and ox-LDL cholesterol only were significantly reduced after 4-AIT. Our data suggest that a single bout of AIT performed three times per week may be a time-efficient strategy to improve VO2max and reduce blood pressure and fasting glucose in previously inactive but otherwise healthy middle-aged individuals. The 1-AIT type of exercise training may be readily implemented as part of activities of daily living and could easily be translated into programs designed to improve public health. TRIAL REGISTRATION: ClinicalTrials.govNCT00839579.

Skeletal Muscle-Specific Expression of PGC-1α-b, an Exercise-Responsive Isoform, Increases Exercise Capacity and Peak Oxygen Uptake

Miki Tadaishi, Shinji Miura, Yuko Kai +3 more · PLoS ONE · 2011 · 162 citations

BACKGROUND: Maximal oxygen uptake (VO(2max)) predicts mortality and is associated with endurance performance. Trained subjects have a high VO(2max) due to a high cardiac output and high metabolic capacity of skeletal muscles. Peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), a nuclear receptor coactivator, promotes mitochondrial biogenesis, a fiber-type switch to oxidative fibers, and angiogenesis in skeletal muscle. Because exercise training increases PGC-1α in skeletal muscle, PGC-1α-mediated changes may contribute to the improvement of exercise capacity and VO(2max). There are three isoforms of PGC-1α mRNA. PGC-1α-b protein, whose amino terminus is different from PGC-1α-a protein, is a predominant PGC-1α isoform in response to exercise. We investigated whether alterations of skeletal muscle metabolism by overexpression of PGC-1α-b in skeletal muscle, but not heart, would increase VO(2max) and exercise capacity. METHODOLOGY/PRINCIPAL FINDINGS: Transgenic mice showed overexpression of PGC-1α-b protein in skeletal muscle but not in heart. Overexpression of PGC-1α-b promoted mitochondrial biogenesis 4-fold, increased the expression of fatty acid transporters, enhanced angiogenesis in skeletal muscle 1.4 to 2.7-fold, and promoted exercise capacity (expressed by maximum speed) by 35% and peak oxygen uptake by 20%. Across a broad range of either the absolute exercise intensity, or the same relative exercise intensities, lipid oxidation was always higher in the transgenic mice than wild-type littermates, suggesting that lipid is the predominant fuel source for exercise in the transgenic mice. However, muscle glycogen usage during exercise was absent in the transgenic mice. CONCLUSIONS/SIGNIFICANCE: Increased mitochondrial biogenesis, capillaries, and fatty acid transporters in skeletal muscles may contribute to improved exercise capacity via an increase in fatty acid utilization. Increases in PGC-1α-b protein or function might be a useful strategy for sedentary subjects to perform exercise efficiently, which would lead to prevention of life-style related diseases and increased lifespan.

Cardiorespiratory fitness levels and their association with cardiovascular profile in patients with rheumatoid arthritis: a cross-sectional study

George S. Metsios, Yiannis Koutedakis, Jet Veldhuijzen Zanten +6 more · Lara D. Veeken · 2015 · 57 citations

OBJECTIVE: The aim of this study was to investigate the association of different physical fitness levels [assessed by the maximal oxygen uptake (VO2max) test] with cardiovascular disease (CVD) risk factors in patients with RA. METHODS: A total of 150 RA patients were assessed for cardiorespiratory fitness with a VO2max test and, based on this, were split in three groups using the 33rd (18.1 ml/kg/min) and 66th (22.4 ml/kg/min) centiles. Classical and novel CVD risk factors [blood pressure, body fat, insulin resistance, cholesterol, triglycerides, high-density lipoprotein (HDL), physical activity, CRP, fibrinogen and white cell count], 10-year CVD risk, disease activity (DAS28) and severity (HAQ) were assessed in all cases. RESULTS: Mean VO2max for all RA patients was 20.9 (s.d. 5.7) ml/kg/min. The 10-year CVD risk (P = 0.003), systolic blood pressure (P = 0.039), HDL (P = 0.017), insulin resistance and body fat (both at P < 0.001), CRP (P = 0.005), white blood cell count (P = 0.015) and fibrinogen (P < 0.001) were significantly different between the VO2max tertiles favouring the group with the higher VO2max levels. In multivariate analyses of variance, VO2max was significantly associated with body fat (P < 0.001), HDL (P = 0.007), insulin resistance (P < 0.003) and 10-year CVD risk (P < 0.001), even after adjustment for DAS28, HAQ and physical activity. CONCLUSION: VO2max levels are alarmingly low in RA patients. Higher levels of VO2max are associated with a better cardiovascular profile in this population. Future studies need to focus on developing effective behavioural interventions to improve cardiorespiratory fitness in RA.

Myocardial Adaptation to High-Intensity (Interval) Training in Previously Untrained Men With a Longitudinal Cardiovascular Magnetic Resonance Imaging Study (Running Study and Heart Trial)

Michael Scharf, Axel Schmid, Wolfgang Kemmler +6 more · Circulation Cardiovascular Imaging · 2015 · 26 citations

BACKGROUND: To prospectively evaluate whether short-term high-intensity (interval) training (HI(I)T) induces detectable morphological cardiac changes in previously untrained men in cardiovascular magnetic resonance imaging. METHODS AND RESULTS: Eighty-four untrained volunteers were randomly assigned to a HI(I)T group (n=42; 44.1±4.7 years) or an inactive control group (n=42; 42.3±5.6 years). HI(I)T focused on interval runs (intensity: 95%-105% of individually calculated heart rate at the anaerobic threshold). Before and after 16 weeks, all subjects underwent physiological examination, stepwise treadmill test with blood lactate analysis, and contrast-enhanced cardiovascular magnetic resonance imaging (cine, tagging, and delayed enhancement). Indexed left ventricular (LV) and right ventricular (RV) volume (LV, 77.1±8.5-83.9±8.6; RV, 80.5±8.5-86.6±8.1) and mass (LV, 58.2±6.4-63.4±8.1; RV, 14.8±1.7-16.1±2.1) significantly increased with HI(I)T. Changes in LV and RV morphological parameters with HI(I)T were highly correlated with an increase in maximal aerobic capacity (VO2max) and a decrease in blood lactate concentration at the anaerobic threshold. Mean LV and RV remodeling index of HI(I)T group did not alter with training (0.76 ±0.09 and 0.24±0.10 g/mL, respectively [P=0.97 and P=0.72]), indicating balanced cardiac adaptation. Myocardial circumferential strain decreased after HI(I)T within all 6 basal segments (anteroseptal, P=0.01 and anterolateral, P<0.001). There was no late gadolinium enhancement in any of the participants before or post HI(I)T. CONCLUSIONS: Sixteen weeks of HI(I)T lead to measurable changes in cardiac atrial and ventricular morphology and function in previously untrained men. This correlates with improvements in parameters of endurance capacity. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01406730.

A Multi-Center Comparison of O2peak Trainability Between Interval Training and Moderate Intensity Continuous Training

Camilla J. Williams, Brendon J. Gurd, Jacob T. Bonafiglia +27 more · Frontiers in Physiology · 2019 · 111 citations

There is heterogeneity in the observed V̇O2peak response to similar exercise training, and different exercise approaches produce variable degrees of exercise response (trainability). The aim of this study was to combine data from different laboratories to compare V̇O2peak trainability between various volumes of interval training and Moderate Intensity Continuous Training (MICT). For interval training, volumes were classified by the duration of total interval time. High-volume High Intensity Interval Training (HIIT) included studies that had participants complete more than 15 minutes of high intensity efforts per session. Low-volume HIIT/Sprint Interval Training (SIT) included studies using less than 15 minutes of high intensity efforts per session. In total, 677 participants across 18 aerobic exercise training interventions from 8 different universities in 5 countries were included in the analysis. Participants had completed 3 weeks or more of either high-volume HIIT (n=299), low-volume HIIT/SIT (n=116), or MICT (n=262) and were predominately men (n=495) with a mix of healthy, elderly and clinical populations. Each training intervention improved mean V̇O2peak at the group level (p<0.001). After adjusting for covariates, high-volume HIIT had a significantly greater (P<0.05) absolute V̇O2peak increase (0.29 L/min) compared to MICT (0.20 L/min) and low-volume HIIT/SIT (0.18 L/min). Adjusted relative V̇O2peak increase was also significantly greater (P<0.01) in high-volume HIIT (3.3 ml/kg/min) than MICT (2.4 ml/kg/min) and insignificantly greater (P=0.09) than low-volume HIIT/SIT (2.5 mL/kg/min). Based on a high threshold for a likely response (technical error of measurement plus the minimal clinically important difference), high-volume HIIT had significantly more (P<0.01) likely responders (31%) compared to low-volume HIIT/SIT (16%) and MICT (21%). Covariates such as age, sex, the individual study, population group, sessions per week, study duration and the average between pre and post V̇O2peak explained only 17.3% of the variance in V̇O2peak trainability. In conclusion, high-volume HIIT had more likely responders to improvements in V̇O2peak compared to low-volume HIIT/SIT and MICT.

Polarized training has greater impact on key endurance variables than threshold, high intensity, or high volume training

Thomas Stöggl, Billy Sperlich · Frontiers in Physiology · 2014 · 275 citations

UNLABELLED: ENDURANCE ATHLETES INTEGRATE FOUR CONDITIONING CONCEPTS IN THEIR TRAINING PROGRAMS: high-volume training (HVT), "threshold-training" (THR), high-intensity interval training (HIIT) and a combination of these aforementioned concepts known as polarized training (POL). The purpose of this study was to explore which of these four training concepts provides the greatest response on key components of endurance performance in well-trained endurance athletes. METHODS: Forty eight runners, cyclists, triathletes, and cross-country skiers (peak oxygen uptake: (VO2peak): 62.6 ± 7.1 mL·min(-1)·kg(-1)) were randomly assigned to one of four groups performing over 9 weeks. An incremental test, work economy and a VO2peak tests were performed. Training intensity was heart rate controlled. RESULTS: POL demonstrated the greatest increase in VO2peak (+6.8 ml·min·kg(-1) or 11.7%, P < 0.001), time to exhaustion during the ramp protocol (+17.4%, P < 0.001) and peak velocity/power (+5.1%, P < 0.01). Velocity/power at 4 mmol·L(-1) increased after POL (+8.1%, P < 0.01) and HIIT (+5.6%, P < 0.05). No differences in pre- to post-changes of work economy were found between the groups. Body mass was reduced by 3.7% (P < 0.001) following HIIT, with no changes in the other groups. With the exception of slight improvements in work economy in THR, both HVT and THR had no further effects on measured variables of endurance performance (P > 0.05). CONCLUSION: POL resulted in the greatest improvements in most key variables of endurance performance in well-trained endurance athletes. THR or HVT did not lead to further improvements in performance related variables.

Greater effects of high- compared with moderate-intensity interval training on cardio-metabolic variables, blood leptin concentration and ratings of perceived exertion in obese adolescent females

Ghazi Racil, Jérémy Coquart, Wassim Elmontassar +5 more · Biology of Sport · 2016 · 143 citations

This study examined the effects of high- vs. moderate-intensity interval training on cardiovascular fitness, leptin levels and ratings of perceived exertion (RPE) in obese female adolescents. Forty-seven participants were randomly assigned to one of three groups receiving either a 1:1 ratio of 15 s of effort comprising moderate-intensity interval training (MIIT at 80% maximal aerobic speed: MAS) or high-intensity interval training (HIIT at 100% MAS), with matched 15 s recovery at 50% MAS, thrice weekly, or a no-training control group. The HIIT and MIIT groups showed improved (p < 0.05) body mass (BM), BMI Z-score, and percentage of body fat (%BF). Only the HIIT group showed decreased waist circumference (WC) (p = 0.017). The effect of exercise on maximal oxygen uptake (VO2max) was significant (p = 0.019, ES = 0.48 and p = 0.010, ES = 0.57, HIIT and MIIT, respectively). The decrease of rate-pressure product (RPP) (p < 0.05, ES = 0.53 and ES = 0.46, HIIT and MIIT, respectively) followed the positive changes in resting heart rate and blood pressures. Blood glucose, insulin level and the homeostasis model assessment index for insulin decreased (p < 0.05) in both training groups. Significant decreases occurred in blood leptin (p = 0.021, ES = 0.67 and p = 0.011, ES = 0.73) and in RPE (p = 0.001, ES = 0.76 and p = 0.017, ES = 0.57) in HIIT and MIIT, respectively. In the post-intervention period, blood leptin was strongly associated with %BF (p < 0.001) and VO2max (p < 0.01) in the HIIT and MIIT groups, respectively, while RPE was strongly associated with BM (p < 0.01) in the HIIT group. The results suggest that high-intensity interval training may produce more positive effects on health determinants in comparison with the same training mode at a moderate intensity.

Running-based high-intensity interval training vs. small-sided game training programs: effects on the physical performance, psychophysiological responses and technical skills in young soccer players

Erşan Arslan, Gamze ERIKOGLU ORER, Filipe Manuel Clemente · Biology of Sport · 2020 · 141 citations

This study aimed to compare the effects of 5-week running-based high-intensity interval training (HIIT) vs. small-sided game training (SSG) on the physical performance, psychophysiological responses and technical skills in young soccer players. Twenty young male soccer players (age: 14.20.5 years, height: 161.87.9 cm) participated in this study and were assigned to two groups: the HIIT group (n=10) and SSG group (n=10). Both groups trained twice per week with a similar total training duration. The SSG consisted of two 5-9 minutes of 2-a-side with 2-minute passive rest periods, whereas the HIIT consisted of 12-20 minutes of continuous runs at intensities (90 to 95%) related to the velocity obtained in the 30-15 intermittent fitness test. Before and after the 5-week training periods the following tests were completed: maximum oxygen consumption (VO 2max ) from the Yo-Yo Intermittent Recovery Test level 1 (YYIRTL-1), 10-30-m sprint test, countermovement jump [CMJ], squat jump [SJ], and drop jump [DJ]), 1000-m run test, zigzag agility, repeated sprint ability, 30-15 intermittent fitness test and speed dribbling ability test. Our results revealed meaningful improvements in YYIRTL-1 performance (SSG: +12.8%, standardized effect size [d]=-1.46; HIIT: +16.4%, d=3.27 and VO 2max (SSG: +3.3%, d=-1.48; HIIT: +4.3%, d=2.61). There was a meaningful greater improvement in agility and technical test performances following the SSG training compared with the HIIT (p 0.05, d=ranging from 0.92 to 1.99). By contrast, the HIIT group showed meaningfully higher performance responses in terms of the 1000-m running time and repeated sprint test ability (p 0.05, d=ranging from 0.90 to 2.06). These results confirmed that SSG training might be a more effective training regime to improve technical ability and agility with greater enjoyment, whereas HIIT might be more suitable for speed-based conditioning in young soccer players.

High-Intensity Aerobic Exercise Improves Both Hepatic Fat Content and Stiffness in Sedentary Obese Men with Nonalcoholic Fatty Liver Disease

Sechang Oh, Rina So, Takashi Shida +7 more · Scientific Reports · 2017 · 140 citations

We compared the effects of 12-week programs of resistance training (RT), high-intensity interval aerobic training (HIAT), and moderate-intensity continuous aerobic training (MICT). The primary goal was to evaluate the therapeutic effects of the exercise modalities for the management of nonalcoholic fatty liver disease (NAFLD). A total of 61 sedentary obese men with NAFLD were randomized into one of the following exercise regimens (RT, HIAT, or MICT). Hepatic fat content was decreased to a similar extent in the RT, HIAT, and MICT groups (-14.3% vs. -13.7% vs. -14.3%) without significant changes in weight and visceral fat. The gene expression levels of fatty acid synthesis were significantly decreased in the subjects' monocytes. Hepatic stiffness was decreased only in the HIAT group (-16.8%). The stiffness change was associated with restored Kupffer cell phagocytic function (+17.8%) and decreased levels of inflammation such as leptin (-13.2%) and ferritin (-14.1%). RT, HIAT, and MICT were equally effective in reducing hepatic fat content, but only HIAT was effective in improving hepatic stiffness and restoring Kupffer cell function. These benefits appeared to be independent of detectable weight and visceral fat reductions; the benefits were acquired through the modulation of in vivo fatty acid metabolism and obesity-related inflammatory conditions.

Fibre-Specific Responses to Endurance and Low Volume High Intensity Interval Training: Striking Similarities in Acute and Chronic Adaptation

Trisha D. Scribbans, Brittany A. Edgett, Kira Vorobej +6 more · PLoS ONE · 2014 · 129 citations

The current study involved the completion of two distinct experiments. Experiment 1 compared fibre specific and whole muscle responses to acute bouts of either low-volume high-intensity interval training (LV-HIT) or moderate-intensity continuous endurance exercise (END) in a randomized crossover design. Experiment 2 examined the impact of a six-week training intervention (END or LV-HIT; 4 days/week), on whole body and skeletal muscle fibre specific markers of aerobic and anaerobic capacity. Six recreationally active men (Age: 20.7 ± 3.8 yrs; VO2peak: 51.9 ± 5.1 mL/kg/min) reported to the lab on two separate occasions for experiment 1. Following a muscle biopsy taken in a fasted state, participants completed an acute bout of each exercise protocol (LV-HIT: 8, 20-second intervals at ∼ 170% of VO2peak separated by 10 seconds of rest; END: 30 minutes at ∼ 65% of VO2peak), immediately followed by a muscle biopsy. Glycogen content of type I and IIA fibres was significantly (p<0.05) reduced, while p-ACC was significantly increased (p<0.05) following both protocols. Nineteen recreationally active males (n = 16) and females (n = 3) were VO2peak-matched and assigned to either the LV-HIT (n = 10; 21 ± 2 yrs) or END (n = 9; 20.7 ± 3.8 yrs) group for experiment 2. After 6 weeks, both training protocols induced comparable increases in aerobic capacity (END: Pre: 48.3 ± 6.0, Mid: 51.8 ± 6.0, Post: 55.0 ± 6.3 mL/kg/min LV-HIT: Pre: 47.9 ± 8.1, Mid: 50.4 ± 7.4, Post: 54.7 ± 7.6 mL/kg/min), fibre-type specific oxidative and glycolytic capacity, glycogen and IMTG stores, and whole-muscle capillary density. Interestingly, only LV-HIT induced greater improvements in anaerobic performance and estimated whole-muscle glycolytic capacity. These results suggest that 30 minutes of END exercise at ∼ 65% VO2peak or 4 minutes of LV-HIT at ∼ 170% VO2peak induce comparable changes in the intra-myocellular environment (glycogen content and signaling activation); correspondingly, training-induced adaptations resulting for these protocols, and other HIT and END protocols are strikingly similar.

Home Exercise Training Improves Exercise Capacity in Cirrhosis Patients: Role of Exercise Adherence

Calvin Kruger, Margaret L. McNeely, Robert J. Bailey +10 more · Scientific Reports · 2018 · 126 citations

Abstract Cirrhosis patients have reduced peak aerobic power (peak VO 2 ) that is associated with reduced survival. Supervised exercise training increases exercise tolerance. The effect of home-based exercise training (HET) in cirrhosis is unknown. The objective was to evaluate the safety and efficacy of 8 weeks of HET on peak VO 2 , 6-minute walk distance (6MWD), muscle mass, and quality of life in cirrhosis. Random assignment to 8 weeks of HET (moderate to high intensity cycling exercise, 3 days/week) or usual care. Exercise adherence defined as completing ≥80% training sessions. Paired t-tests and analysis of covariance used for comparisons. Forty patients enrolled: 58% male, mean age 57 y, 70% Child Pugh-A. Between group increases in peak VO 2 (1.7, 95% CI: −0.33 to 3.7 ml/kg/min, p = 0.09) and 6MWD (33.7, 95% CI: 5.1 to 62.4 m, p = 0.02) were greater after HET versus usual care. Improvements even more marked in adherent subjects for peak VO 2 (2.8, 95% CI: 0.5–5.2 mL/kg/min, p = 0.02) and 6MWD (46.4, 95% CI: 12.4–80.5 m, p = 0.009). No adverse events occurred during testing or HET. Eight weeks of HET is a safe and effective intervention to improve exercise capacity in cirrhosis, with maximal benefits occurring in those who complete ≥80% of the program.

Effects of a Low-Volume Aerobic-Type Interval Exercise on V˙O2max and Cardiac Mass

Tomoaki Matsuo, Kousaku Saotome, Satoshi Seino +6 more · Medicine & Science in Sports & Exercise · 2013 · 124 citations

PURPOSE: The aim of this study was to compare the effects of time-efficient, low-volume interval exercises on cardiorespiratory capacity and left ventricular (LV) mass with traditional continuous exercise in sedentary adults. METHODS: Forty-two healthy but sedentary male subjects (age 26.5 ± 6.2 yr) participated in an 8-wk, five times per week, supervised exercise intervention. They were randomly assigned to one of three exercise protocols: sprint interval training (SIT, 5 min, 100 kcal), high-intensity interval aerobic training (HIAT, 13 min, 180 kcal), and continuous aerobic training (CAT, 40 min, 360 kcal). Cardiorespiratory capacity (V˙O2max) and LV mass (3T-MRI) were measured preintervention and postintervention. RESULTS: We observed significant (P < 0.01) increases in V˙O2max in all three groups, and the effect of the HIAT was the greatest of the three (SIT, 16.7% ± 11.6%; HIAT, 22.5% ± 12.2%; CAT, 10.0% ± 8.9%; P = 0.01). There were significant changes in LV mass, stroke volume (SV), and resting HR in both the SIT (LV mass, 6.5% ± 8.3%; SV, 5.3% ± 8.3%; HR, -7.3% ± 11.1%; all P < 0.05) and HIAT (LV mass, 8.0% ± 8.3%; SV, 12.1% ± 9.8%; HR, -12.7% ± 12.2%; all P < 0.01) but not in the CAT (LV mass, 2.5% ± 10.1%; SV, 3.6% ± 6.6%; HR, -2.2% ± 13.3%; all P > 0.05). CONCLUSIONS: Our study revealed that V˙O2max improvement with the HIAT was greater than with the CAT despite the HIAT being performed with a far lower volume and in far less time than the CAT. This suggests that the HIAT has potential as a time-efficient training mode to improve V˙O2max in sedentary adults.

The effects of time and intensity of exercise on novel and established markers of CVD in adolescent youth

Duncan S. Buchan, Stewart Ollis, John D. Young +6 more · American Journal of Human Biology · 2011 · 122 citations

OBJECTIVES: This article examines the effects of brief, intense exercise in comparison with traditional endurance exercise on both novel and traditional markers of cardiovascular disease (CVD) in youth. METHODS: Forty seven boys and ten girls (16.4 ± 0.7 years of age) were divided into a moderate (MOD), high intensity (HIT), or a control group. The MOD group (12 boys, 4 girls) and HIT group (15 boys, 2 girls) performed three weekly exercise sessions over 7 weeks. Each session consisted of either four to six repeats of maximal sprint running within a 20 m area with 20-30 s recovery (HIT) or 20 min continuous running within a 20 m area at ∼70% maximal oxygen uptake (VO(2) max). RESULTS: Total exercise time commitment over the intervention was 420 min (MOD) and 63 min (HIT). Training volume was 85% lower for the HIT group. Total estimated energy expenditure was ∼907.2 kcal (HIT) and ∼4410 kcal (MOD). Significant improvements (P ≤ 0.05) were found in systolic blood pressure, aerobic fitness, and body mass index (BMI) postintervention (HIT). In the MOD group, significant (P ≤ 0.05) improvements were noted in aerobic fitness, percentage body fat (%BF), BMI, fibrinogen (Fg), plasminogen activator inhibitor-1, and insulin concentrations. CONCLUSIONS: These findings demonstrate that brief, intense exercise is a time efficient means for improving CVD risk factors in adolescents.

Cardiovascular Exercise Training Extends Influenza Vaccine Seroprotection in Sedentary Older Adults: The Immune Function Intervention Trial

Jeffrey A. Woods, K. Todd Keylock, Thomas Lowder +9 more · Journal of the American Geriatrics Society · 2009 · 179 citations

OBJECTIVES: To determine whether cardiovascular exercise training resulted in improved antibody responses to influenza vaccination in sedentary elderly people who exhibited poor vaccine responses. DESIGN: Single-site randomized parallel-arm 10-month controlled trial. SETTING: University of Illinois at Urbana-Champaign. PARTICIPANTS: One hundred forty-four sedentary, healthy older (69.9 +/- 0.4) adults. INTERVENTIONS: Moderate (60-70% maximal oxygen uptake) cardiovascular exercise was compared with flexibility and balance training. MEASUREMENTS: The primary outcome was influenza vaccine response, as measured according to hemagglutination inhibition (HI) anti-influenza antibody titer and seroprotective responses (HI titer > or =40). Secondary measures included cardiovascular fitness and body composition. RESULTS: Of the 160 participants enrolled, 144 (90%) completed the 10-month intervention with excellent compliance ( approximately 83%). Cardiovascular, but not flexibility, exercise intervention resulted in improvements in indices of cardiovascular fitness, including maximal oxygen uptake. Although not affecting peak (e.g., 3 and 6 weeks) postvaccine anti-influenza HI titers, cardiovascular exercise resulted in a significant increase in seroprotection 24 weeks after vaccination (30-100% dependent on vaccine variant), whereas flexibility training did not. CONCLUSION: Participants randomized to cardiovascular exercise experienced improvements in influenza seroprotection throughout the entire influenza season, whereas those in the balance and flexibility intervention did not. Although there were no differences in reported respiratory tract infections, the exercise group exhibited reduced overall illness severity and sleep disturbance. These data support the hypothesis that regular endurance exercise improves influenza vaccine responses.

Improvement of $$\dot{V}\hbox{O}_{2 \max},$$ by cardiac output and oxygen extraction adaptation during intermittent versus continuous endurance training

Frédéric Daussin, Elodie Ponsot, Stéphane Dufour +5 more · European Journal of Applied Physiology · 2007 · 175 citations

Effects of High-Intensity Interval Training versus Continuous Training on Physical Fitness, Cardiovascular Function and Quality of Life in Heart Failure Patients

Nathalie M. M. Benda, Joost P. H. Seeger, Guus G. C. F. Stevens +6 more · PLoS ONE · 2015 · 109 citations

INTRODUCTION: Physical fitness is an important prognostic factor in heart failure (HF). To improve fitness, different types of exercise have been explored, with recent focus on high-intensity interval training (HIT). We comprehensively compared effects of HIT versus continuous training (CT) in HF patients NYHA II-III on physical fitness, cardiovascular function and structure, and quality of life, and hypothesize that HIT leads to superior improvements compared to CT. METHODS: Twenty HF patients (male:female 19:1, 64±8 yrs, ejection fraction 38±6%) were allocated to 12-weeks of HIT (10*1-minute at 90% maximal workload-alternated by 2.5 minutes at 30% maximal workload) or CT (30 minutes at 60-75% of maximal workload). Before and after intervention, we examined physical fitness (incremental cycling test), cardiac function and structure (echocardiography), vascular function and structure (ultrasound) and quality of life (SF-36, Minnesota living with HF questionnaire (MLHFQ)). RESULTS: Training improved maximal workload, peak oxygen uptake (VO2peak) related to the predicted VO2peak, oxygen uptake at the anaerobic threshold, and maximal oxygen pulse (all P<0.05), whilst no differences were present between HIT and CT (N.S.). We found no major changes in resting cardiovascular function and structure. SF-36 physical function score improved after training (P<0.05), whilst SF-36 total score and MLHFQ did not change after training (N.S.). CONCLUSION: Training induced significant improvements in parameters of physical fitness, although no evidence for superiority of HIT over CT was demonstrated. No major effect of training was found on cardiovascular structure and function or quality of life in HF patients NYHA II-III. TRIAL REGISTRATION: Nederlands Trial Register NTR3671.

Impact of low-volume, high-intensity interval training on maximal aerobic capacity, health-related quality of life and motivation to exercise in ageing men

Ann‐Marie Knowles, Peter N. Herbert, Chris Easton +2 more · AGE · 2015 · 98 citations

Self-reported physical activity compared with maximal oxygen uptake in adults

Mette Aadahl, Michael Kjær, Jens Kristensen +2 more · European Journal of Cardiovascular Prevention & Rehabilitation · 2007 · 137 citations

BACKGROUND: Physical activity level and cardiorespiratory fitness are both inversely associated with the risk of cardiovascular diseases and with all-cause mortality. Physical activity questionnaires are often validated against objectively measured maximal oxygen uptake (VO2max). AIM: To validate a self-report physical activity questionnaire against VO2max and furthermore to establish whether a simple question on self-rated physical fitness could predict objectively measured VO2max. METHODS: A total of 102 men and women aged between 35 and 65 years were recruited from an ongoing population-based intervention study, the Inter99 Study. Participants reported their self-rated fitness and daily physical activity using a new questionnaire based on metabolic equivalents (MET). VO2max (ml/kg per min) was determined using a graded bicycle test with increasing workload until exhaustion and with simultaneous measurement of breath-to-breath oxygen uptake in 15-s periods. Statistical analyses were performed by linear regression analyses using the self-reported physical activity level as an independent variable and VO2max (l/min) as an dependent variable, and with covariates sex, age and bodyweight. RESULTS: Data from 53 men and 47 women were analysed. The amount of daily vigorous activity (>6 MET) was significantly positively associated with VO2max (P=0.0001, R=0.76), whereas the total amount of physical activity was not significantly associated with VO2max (P=0.098, R=0.69). A significant trend across three groups of self-rated fitness in relation to VO2max (ml/kg per min) was found (P for trend <0.0001). CONCLUSION: The physical activity questionnaire has acceptable validity when compared with VO2max in adult men and women. Furthermore, a simple question on self-rated fitness seems to reflect measured VO2max objectively.

Blood Volume Expansion and Cardiorespiratory Function: Effects of Training Modality

Darren E. R. Warburton, Mark J. Haykowsky, H. Arthur Quinney +5 more · Medicine & Science in Sports & Exercise · 2004 · 131 citations

PURPOSE: To evaluate the effects of different modalities of aerobic (i.e., interval (INT) and continuous (CONT)) training on cardiorespiratory function and the importance of training-induced blood volume (BV) expansion on aerobic power and LV function. We hypothesized that if modality-mediated differences in cardiorespiratory function exist after INT and CONT, they would be related directly to differences in training-induced hypervolemia. METHODS: We examined the effects of 12 wk of CONT and INT on BV, volume-regulatory hormones (angiotensin II, aldosterone, atrial natriuretic peptide), and cardiorespiratory function in 20 untrained males (mean age 30 +/- 4 (SD)). Participants were stratified (mass and VO2max) and randomly assigned to control, CONT, or INT. RESULTS: There were no significant changes in cardiorespiratory function or BV in the control group. Twelve weeks of continuous and interval training, respectively, resulted in significant changes in VO2max (23 +/- 18 vs 21 +/- 10%), peak stroke volume (20 +/- 18 vs 11 +/- 18%), and BV (12 +/- 9 vs 10 +/- 6%). Changes in VO2max were directly related to changes in BV (r = 0.47). Angiotensin II significantly increased after 1 wk of CONT and INT and thereafter returned to baseline values. There was no significant difference between the CONT and INT groups with regard to changes in vascular volumes, volume-regulatory hormones, and/or cardiorespiratory function. CONCLUSIONS: These data indicate that: 1) 12 wk of CONT and INT result in similar improvements in VO2max, and LV function and 2) training-induced hypervolemia accounts for approximately 47% of the changes in VO2max after CONT and INT.

Combined exercise reduces arterial stiffness, blood pressure, and blood markers for cardiovascular risk in postmenopausal women with hypertension

Won-Mok Son, Ki-Dong Sung, Jae-Min Cho +1 more · Menopause The Journal of The North American Menopause Society · 2016 · 115 citations

OBJECTIVE: Postmenopausal women exhibit elevated brachial-ankle pulse wave velocity (baPWV), an indicator of arterial stiffness, which is associated with an increased risk of cardiovascular events and mortality. The purpose of this study is to examine the impact of combined resistance and aerobic exercise training on baPWV, blood pressure (BP), and cardiovascular fitness in postmenopausal women with stage 1 hypertension. METHODS: Twenty postmenopausal women (age, 75 ± 2 y; systolic BP, 152 ± 2 mm Hg, diastolic BP, 95 ± 3 mm Hg) were randomly assigned to a "no-exercise" (CON, n = 10) or combined exercise (EX, n = 10) group. The EX group performed resistance and aerobic exercise for 12 weeks, 3 times per week. Exercise intensity was increased gradually, from 40% to 70% of heart rate reserve, every 4 weeks. BaPWV, BP, blood nitrite/nitrate, endothelin-1 (ET-1), cardiovascular fitness, and body composition were measured before and after the 12-week intervention. RESULTS: BP, baPWV (-1.2 ± 0.4 m/s), ET-1 (-2.7 ± 0.3 μmol/mL), nitrite/nitrate (+4.5 ± 0.5 μM), functional capacity, and body composition were significantly improved (P < 0.05) in the EX group after 12 weeks of training, but no changes were observed in the CON group. CONCLUSIONS: These findings indicate that 12 weeks of combined exercise training improves arterial stiffness, BP, ET-1, blood nitrite/nitrate, functional capacity, and body composition in postmenopausal women with stage 1 hypertension. Thus, this study provides evidence that combined exercise training is a useful therapeutic method to improve cardiovascular health which can reduce cardiovascular disease risk in postmenopausal women with hypertension.

Cardiorespiratory Fitness and Cognition: Longitudinal Associations in the FINGER Study

Heikki Pentikäinen, Kai Savonen, Tiia Ngandu +7 more · Journal of Alzheimer s Disease · 2019 · 60 citations

BACKGROUND: Previous studies have found positive associations between cardiorespiratory fitness (CRF) and cognitive performance in older people but data are inconsistent and have methodological limitations. OBJECTIVE: Our aim was to study the longitudinal associations of CRF with executive functions, processing speed and memory as well as with the overall cognitive function in older people at risk for cognitive impairment. METHODS: Participants (n = 421), mean age 69.0, were a sub-sample of The Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER). To be eligible, individuals were required to be 60-77 years old with a CAIDE (Cardiovascular Risk Factors, Aging and Dementia) Dementia Risk Score of at least 6 points and cognition at mean level or slightly lower than expected for age. CRF was assessed as peak oxygen uptake (VO2peak, L/min) measured directly in a symptom-limited maximal exercise test on cycle ergometer at baseline and at 24 months. Cognitive performance was assessed using an extensive neuropsychological test battery (NTB) at baseline and at 24 months. NTB data were standardized to Z scores, and analyzed with the linear mixed model. RESULTS: Over two years, VO2peak was associated with NTB total score (β= 0.12, p = 0.01), executive functions (β= 0.16, p = 0.01), and processing speed (β= 0.25, p < 0.001), but not with memory (β= 0.11, p = 0.12). CONCLUSION: Over two years follow-up, CRF was associated with executive functions and processing speed, and was related also to the overall cognitive function.

Effectiveness and Safety of High-Intensity Interval Training in Patients With Type 2 Diabetes

Monique E. François, Jonathan P. Little · Diabetes Spectrum · 2015 · 148 citations

IN BRIEF Recent research has shown that high-intensity interval training (HIIT) can promote improvements in glucose control and cardiovascular health in individuals with type 2 diabetes. This article summarizes the evidence and highlights the ways in which HIIT might be safely implemented as an adjunct to more traditional exercise approaches.

Cardiorespiratory fitness levels and associations with physical activity and body composition in young South African adults from Soweto

Alessandra Prioreschi, Søren Brage, Kate Westgate +2 more · BMC Public Health · 2017 · 27 citations

This observational study aims to describe fitness, and objectively measured physical activity levels and patterns in 409 young black South African adults (aged 19–20 years) from Soweto, as well as to examine associations between physical activity, fitness and BMI. A sub-maximal ramped step test was used to obtain an estimate of maximal oxygen uptake (VO2max). Physical activity was measured using ActiGraph (GT1M) for 7 days in 256 participants. Time spent in sedentary (<100 counts per minute (cpm)), moderate (2020–5998 cpm) and vigorous (≥5999 cpm) intensity activity was calculated, and 90% of participants were considered active. Data are presented as mean(CI) or median(CI). Overweight and obesity was more prevalent in females than males (35% vs 8%, p < 0.001). Males had a higher VO2max than females (41.9(41, 43) vs 32.6(32, 33)mlO2/kg/min, p < 0.001); spent more time in moderate to vigorous intensity physical activity (MVPA) (83(80, 94) vs 43(38, 45)min/day, p < 0.001), and less time in sedentary behaviours (541(541, 567) vs 575(568, 597)min/day, p < 0.01). Sedentary time was not associated with VO2max, however BMI was inversely associated, and MVPA was positively associated, with VO2max (both p < 0.001). The majority of young South African adults in this study were sufficiently active, and higher MVPA was associated with fitness. However, the high level of sedentary behaviour in this population is of concern and may be contributing to the increasing prevalence of overweight and obesity in this population. Young South African females are at greatest risk for decreased cardiovascular fitness and should be the focus for future interventions.

Levels of homocysteine are inversely associated with cardiovascular fitness in women, but not in men: data from the National Health and Nutrition Examination Survey 1999–2002

Hsin‐Wei Kuo, Chung‐Jen Yen, Jonathan F. Bean · Journal of Internal Medicine · 2005 · 55 citations

OBJECTIVES: Cardiovascular fitness represents the ability of active skeletal muscle to utilize oxygen during aerobic exercise. Elevated homocysteine, causing tissue injury by such mechanisms as oxidative stress, endothelial damage, and protein homocysteinylation, is associated with increased risk of cardiovascular disease, dementia and osteoporotic fracture. However, the association between elevated homocysteine and cardiovascular fitness has not been reported. DESIGN: Population-based cross-sectional study. SETTING: National Health and Nutrition Examination Survey from 1999 to 2002 in the USA. SUBJECTS: A total of 1444 noninstitutionalized adults aged 20--49 years with reliable measures of cardiovascular fitness and non-missing values in homocysteine. Main outcome measures. Cardiovascular fitness, estimated maximal oxygen uptake or VO(2)max (mL kg(-1) min(-1)), was obtained by a submaximal exercise test. Levels of homocysteine were measured by the Abbott homocysteine assay, a fully automated fluorescence polarization immunoassay method and were natural-log-transformed due to right skewness. RESULTS. After adjustment for age, race and body mass index, there was a 0.70 mL kg(-1) min(-1) decrease (P=0.033) in the estimated VO(2)max for each standard deviation (SD) increase in the natural-log-transformed homocysteine level for women. Additional adjustment of hypertension, diabetes, smoking status, alcohol intake, use of lipid-lowering agents, physical activity, self-report health condition, as well as levels of folate, vitamin B(12), creatinine, C-reactive protein, total cholesterol and haemoglobin seemed to influence the association. In the fully adjusted model, we observed a 1.18 mL kg(-1) min(-1) decrease (P=0.003) in the estimated VO(2)max for each SD increase in the natural-log-transformed homocysteine level in women. There was no association between cardiovascular fitness and homocysteine levels in men. CONCLUSION. High homocysteine levels were inversely associated with cardiovascular fitness in women, but not in men. The results suggest that homocysteine levels are important indicators of exercise tolerance amongst women and may be useful in targeting female individuals requiring endurance intervention to prevent loss of cardiovascular fitness and function.

High intensity interval exercise training in overweight young women.

Tan Sijie, Y Hainai, Y Fengying +1 more · PubMed · 2012 · 94 citations

AIM: The purpose of this study was intended to evaluate the effects of a high intensity interval training (HIIT) program on the body composition, cardiac function and aerobic capacity in overweight young women. METHODS: Sixty female university students (aged 19-20, BMI≥25kg/m2 and percentage body fat ≥ 30%) were chosen and then randomly assigned to each of the HIIT group, the moderate intensity continuous training (MICT) group and the non-training control group. The subjects in both the HIIT and MICT groups underwent exercise training five times per week for 12 weeks. In each of the training sessions, the HIIT group performed interval exercises at the individualized heart rate (HR) of 85% of VO2max and separated by brief periods of low intensity activity (HR at 50% of VO2max), while the MICT group did continuous walking and/or jogging at the individualized HR of 50% of VO2max. RESULTS: Both of these exercise training programs produced significant improvements in the subjects' body composition, left ventricular ejection fraction, heart rate at rest, maximal oxygen uptake and ventilatory threshold. However, the HIIT group achieved better results than those in the MICT group, as it was evaluated by the amount of the effect size. The control group did not achieve any change in all of the measured variables. CONCLUSION: The tangible results achieved by our relatively large groups of homogeneous subjects have demonstrated that the HIIT program is an effective measure for the treatment of young women who are overweight.

Effects of Heart Rate vs. Speed-Based High Intensity Interval Training on Aerobic and Anaerobic Capacity of Female Soccer Players

Hamid Arazi, Abbas Keihaniyan, Amin Eatemadyboroujeni +4 more · Sports · 2017 · 68 citations

The purpose of this study was to compare the effects of two types of high-intensity interval training (HIIT) programs on aerobic and anaerobic capacity of female soccer players. Regional-level female athletes were randomly divided into heart rate-based HIIT (n = 8; age 23.4 ± 1.1 year) and speed-based HIIT groups (n = 8; age 23.4 ± 1.3 year). Athletes trained three days per week for six weeks. Before and after training, each athlete’s performance was assessed directly through the Hoff test, 30-15 Intermittent Fitness Test (VIFT), and repeated-sprint ability test (RAST); maximal oxygen consumption (VO2max), power and fatigue were estimated indirectly. Both experimental groups improved power, fatigue index and VO2max after training (p &lt; 0.05). It was noteworthy that the speed-based group had greater gains in minimal power (effect size (ES): 3.99 vs. 0.75), average power (ES: 2.23 vs. 0.33), and fatigue index (ES: 2.53 vs. 0.17) compared to heart rate-based group (p &lt; 0.05). In conclusion, both heart rate-based and speed-based HIIT induced meaningful improvements in power, VO2max, and fatigue index in female soccer players, although the speed-based HIIT group achieved greater gains in power and fatigue index compared to the heart rate-based group.

High-intensity intermittent exercise and cardiovascular and autonomic function

Mehrdad Heydari, Yati N. Boutcher, Stephen H. Boutcher · Clinical Autonomic Research · 2012 · 91 citations

Effectiveness of three models for comprehensive cardiovascular disease risk reduction

Neil F. Gordon, Carla D English, Aashish Contractor +4 more · The American Journal of Cardiology · 2002 · 97 citations

A practical model of low-volume high-intensity interval training induces performance and metabolic adaptations that resemble 'all-out' sprint interval training.

Mahdi Bayati, Babak Farzad, R Gharakhanlou +1 more · PubMed · 2011 · 84 citations

Recently, a novel type of high-intensity interval training known as sprint interval training has demonstrated increases in aerobic and anaerobic performance with very low time commitment. However, this type of training program is unpractical for general populations. The present study compared the impact of a low-volume high-intensity interval training to a "all-out" sprint interval training. Twenty-four active young males were recruited and randomized into three groups: (G1: 3-5 cycling bouts ˟ 30-s all-out with 4 min recovery; G2: 6- 10 cycling bouts ˟ 125% Pmax with 2 min recovery) and a non-trained control group. They all performed a VO2max test, a time to exhaustion at Pmax (Tmax) and a Wingate test before and after the intervention. Capillary blood lactate was taken at rest, 3, and 20 min after the Wingate trial. Training was performed 3 sessions per week for 4 weeks. In G1, significant improvements (p < 0.05) following training were found in VO2max (9.6%), power at VO2max (12.8%), Tmax (48.4%), peak power output (10.3%) and mean power output (17.1%). In G2, significant improvements following training were found in VO2max (9.7%), power at VO2max (16.1%), Tmax (54.2%), peak power output (7.4%; p < 0.05), but mean power output did not change significantly. Blood lactate recovery (20(th) min) significantly decreased in G1 and G2 when compared with pre-testing and the CON group (p < 0.05). In conclusion, the results of the current study agree with earlier work demonstrating the effectiveness of 30-s all-out training program to aerobic and anaerobic adaptations. Of substantial interest is that the low volume high intensity training provides similar results but involves only half the intensity with double the repetitions. Key pointsGiven the markedly lower training volume in the training groups, our results suggest that intense interval training is indeed a time-efficient strategy to induce rapid metabolic and performance adaptations.The results demonstrate that a practical low-volume HIT program is effective for improving metabolic and performance adaptations that resemble many of the same performance gains occurred in all-out SIT protocol.