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1.
Effects of very low volume high intensity versus moderate intensity interval training in obese metabolic syndrome patients: a randomized controlled study.
Reljic, D, Frenk, F, Herrmann, HJ, Neurath, MF, Zopf, Y
Scientific reports. 2021;(1):2836
Abstract
Physical activity is a cornerstone in the treatment of obesity and metabolic syndrome (MetS). Given the leading physical activity barrier of time commitment and safety concerns about vigorous exercise in high-risk groups, this study aimed to investigate the effects of two extremely time-efficient training protocols (< 30 min time effort per week), either performed as high- (HIIT) or moderate-intensity interval training (MIIT) over 12 weeks, in obese MetS patients. In total, 117 patients (49.8 ± 13.6 years, BMI: 38.2 ± 6.2 kg/m2) were randomized to HIIT (n = 40), MIIT (n = 37) or an inactive control group (n = 40). All groups received nutritional counseling to support weight loss. Maximal oxygen uptake (VO2max), MetS severity (MetS z-score), body composition and quality of life (QoL) were assessed pre-and post-intervention. All groups significantly reduced body weight (~ 3%) but only the exercise groups improved VO2max, MetS z-score and QoL. VO2max (HIIT: + 3.1 mL/kg/min, p < 0.001; MIIT + 1.2 mL/kg/min, p < 0.05) and MetS z-score (HIIT: - 1.8 units, p < 0.001; MIIT - 1.2 units, p < 0.01) improved in an exercise intensity-dependent manner. In conclusion, extremely low-volume interval training, even when done at moderate intensity, is sufficiently effective to improve cardiometabolic health in obese MetS patients. These findings underpin the crucial role of exercise in the treatment of obesity and MetS.
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2.
Changes in Menopausal Risk Factors in Early Postmenopausal Osteopenic Women After 13 Months of High-Intensity Exercise: The Randomized Controlled ACTLIFE-RCT.
Hettchen, M, von Stengel, S, Kohl, M, Murphy, MH, Shojaa, M, Ghasemikaram, M, Bragonzoni, L, Benvenuti, F, Ripamonti, C, Benedetti, MG, et al
Clinical interventions in aging. 2021;:83-96
Abstract
The menopausal transition is a critical period in women's lives. Exercise might be the most promising non-pharmaceutic intervention to address the large variety of risk factors related to the pronounced estradiol decline during peri- and early-postmenopause. The aim of this study was to determine the effect of an 18-month multipurpose exercise program on risk factors and symptoms related to the menopausal transition. Fifty-four women 1-5 years postmenopause with osteopenia or osteoporosis were randomly assigned 1) to a high impact weight-bearing/high-intensity/velocity resistance training group (EG: n=27) exercising three times a week or 2) to an attendance control group (CG: n=27) that performed low-intensity exercise once a week. Both groups were supplemented with cholecalciferol and calcium. The primary study endpoint was bone mineral density (BMD) at lumbar spine (LS) and total hip, secondary outcomes were lean body mass (LBM), total and abdominal body percentage, metabolic syndrome Z-Score (MetS-Z), menopausal symptoms and muscle strength and power. Due to COVID-19, the study was stopped after 13 months. We observed significant effects for BMD-LS (EG: 0.002±.018 versus CG: -.009±0.018 mg/cm2, p=0.027) but not for BMD total hip (EG: -0.01±.016 versus CG: -.009±0.020 mg/cm2, p=0.129). LBM improved significantly in the EG and decreased in the CG (0.39±1.08 vs -0.37±1.34 kg, p=0.026). Total and abdominal body fat improved significantly in the EG and was maintained in the CG (-1.44±1.49 vs -0.02±1.55 kg, p=0.002 and -1.50±2.33 vs 0.08±2.07 kg, p=0.011). Significant effects in favor of the EG were also determined for menopausal symptoms (p=0.029), hip/leg extension strength (p<0.001) and power (p<0.001). However, changes of the MetS-Z did not differ significantly (p=0.149) between EG and CG. In summary, with minor exceptions, we demonstrated the effectiveness of a multipurpose exercise protocol dedicated to early-postmenopausal women on various risk factors and complaints related to the menopausal transition.
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3.
Can high-intensity interval training improve physical and mental health outcomes? A meta-review of 33 systematic reviews across the lifespan.
Martland, R, Mondelli, V, Gaughran, F, Stubbs, B
Journal of sports sciences. 2020;(4):430-469
Abstract
High-intensity-interval-training (HIIT) has been suggested to have beneficial effects in multiple populations across individual systematic reviews, although there is a lack of clarity in the totality of the evidence whether HIIT is effective and safe across different populations and outcomes. The aim of this meta-review was to establish the benefits, safety and adherence of HIIT interventions across all populations from systematic reviews and meta-analyses. Major databases were searched for systematic reviews (with/without meta-analyses) of randomised & non-randomised trials that compared HIIT to a control. Thirty-three systematic reviews (including 25 meta-analyses) were retrieved encompassing healthy subjects and people with physical health complications. Evidence suggested HIIT improved cardiorespiratory fitness, anthropometric measures, blood glucose and glycaemic control, arterial compliance and vascular function, cardiac function, heart rate, some inflammatory markers, exercise capacity and muscle mass, versus non-active controls. Compared to active controls, HIIT improved cardiorespiratory fitness, some inflammatory markers and muscle structure. Improvements in anxiety and depression were seen compared to pre-training. Additionally, no acute injuries were reported, and mean adherence rates surpassed 80% in most systematic reviews. Thus, HIIT is associated with multiple benefits. Further large-scale high-quality studies are needed to reaffirm and expand these findings.Abbreviations: ACSM American College of Sports Medicine; BMI: Body Mass Index; BNP: Brain Natriuretic Peptide; BP: Blood Pressure; CAD: Coronary Artery Disease; CHD: Coronary Heart Disease; COPD Chronic Obstructive Pulmonary Disease; CRP: c- reactive Protein; CVD: Cardiovascular Disease; DBP: Diastolic Blood Pressure; ES: Effect Size; FAS: Reduced Fatty Acid Synthase; FATP-1: Reduced Fatty Acid Transport Protein 1; FMD: Flow Mediated Dilation; Hs-CRP: High-sensitivity c- reactive Protein; HDL: High Density Lipoprotein; HIIT High-Intensity Interval Training; HOMA Homoeostatic Model Assessment; HR: Heart Rate; HTx: Heart Transplant Recipients; IL-6: Interleukin-6; LDL: Low Density Lipoprotein; LV: Left Ventricular; LVEF Left Ventricular Ejection Fraction; MD: Mean Difference; MetS: Metabolic Syndrome; MPO: Myeloperoxidase; MICT Moderate-Intensity Continuous Training; NO: Nitric Oxide; NRCT Non-Randomised Controlled Trial; PA: Physical Activity; PAI-1: Plasminogen-activator-inhibitor-1; QoL: Quality of Life; RCT: Randomised Controlled Trial; RoB: Risk of Bias; RPP: Rate Pressure Product; RT: Resistance Training; SBP: Systolic Blood Pressure; SD: Standardised Difference; SMD: Standardised Mean Difference; TAU: Treatment-As-Usual; T2DM: Type 2 Diabetes Mellitus; TC: Total Cholesterol; TG: Triglycerides; TNF-alfa: Tumour Necrosis Factor alpha; UMD: Unstandardised Mean Difference; WC: Waist Circumference; WHR: Waist-to-Hip Ratio; WMD: Weighted Mean DifferenceKey points: HIIT may improve cardiorespiratory fitness, cardiovascular function, anthropometric variables, exercise capacity, muscular structure and function, and anxiety and depression severity in healthy individuals and those with physical health disorders.Additionally, HIIT appears to be safe and does not seem to be associated with acute injuries or serious cardiovascular events.
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4.
Impact of 5-week high-intensity interval training on indices of cardio metabolic health in men.
Lira, FS, Antunes, BM, Figueiredo, C, Campos, EZ, Panissa, VLG, St-Pierre, DH, Lavoie, JM, Magri-Tomaz, L
Diabetes & metabolic syndrome. 2019;(2):1359-1364
Abstract
PURPOSE To compare the acute and chronic effects of high-intensity intermittent training (HIIT) and moderate-intensity continuous training (MICT) on indices of cardio-metabolic health: (HDL-c, total cholesterol, triglycerides, heart ratio, and phase angle/PhA) in physically active men. METHODS Twenty active men were randomly allocated to HIIT (n = 10), or MICT (n = 10) for 5 weeks, three times per week. HIIT consisted of running 5 km with 1-min at 100% of maximal aerobic speed interspersed by 1-min passive recovery while subjects in MICT group ran continuously the same 5 km at 70% of maximal aerobic speed. Blood samples were collected at different moments during the first and last exercise session. Before and after 5 weeks of both exercise training protocols, heart ratio (during exercise session) and PhA were measured pre and post-exercise training. RESULTS Fasting HDL-c levels did not change after 5 weeks of HIIT or MICT. Perceptual variation of HDL pre and post training (fed state) tended to differ between HIIT and MICT (p = 0.09). All lipoproteins parameters (HDL-c, total cholesterol, triglycerides and non-HDL) were increased in post-acute exercise session compared to pre-exercise during the first and last training session, these being observed after both training protocols. PhA and heart rate measured at different times during the first and last training session were not affected in both training protocols. CONCLUSION These results indicate that HIIT and MICT modify the post-exercise lipoprotein profile acutely. On the other hand, only HIIT tended to increase HDL-c levels chronically.
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5.
Reduced Exertion High-Intensity Interval Training is More Effective at Improving Cardiorespiratory Fitness and Cardiometabolic Health than Traditional Moderate-Intensity Continuous Training.
Cuddy, TF, Ramos, JS, Dalleck, LC
International journal of environmental research and public health. 2019;(3)
Abstract
This study sought to determine the effectiveness of an 8 wk reduced-exertion high-intensity interval training (REHIT) at improving cardiorespiratory fitness (CRF) and positively modifying cardiometabolic health in the workplace environment. Participants (n = 32) were randomized to two groups: (1) One group (n = 16) was prescribed an 8 wk REHIT program, and (2) one group (n = 16) was prescribed moderate-intensity continuous training (MICT). Cardiometabolic risk factors and CRF were measured at baseline and 8 wks. After 8 wks, changes in CRF (REHIT, 12%; MICT, 7%), systolic blood pressure (REHIT, -5%; MICT, -2%), waist circumference (REHIT, -1.4%; MICT, -0.3%), and metabolic syndrome (MetS) severity (MetS z-score: REHIT, -62%; MICT, 27%) were more favorable (p < 0.05) in the REHIT group relative to the MICT group. Interestingly, there was a significantly greater proportion of participants in the REHIT group (75%, 9/12) who had a favorable change in the MetS z-score (Δ > -0.60) relative to the MICT group (47%, 7/15). The main finding of the present study is that 8 wks REHIT elicited more potent and time-efficient improvements in CRF and cardiometabolic health when compared to traditional MICT. This study provides critical evidence for implementation of the sprint interval training (SIT) paradigm from the scientific literature into a real-world workplace setting.
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6.
High-intensity interval training and cardiac autonomic control in individuals with metabolic syndrome: A randomised trial.
Ramos, JS, Dalleck, LC, Borrani, F, Beetham, KS, Mielke, GI, Dias, KA, Wallen, MP, Keating, SE, Fassett, RG, Coombes, JS
International journal of cardiology. 2017;:245-252
Abstract
BACKGROUND Insulin resistance has been postulated to play a central role in the co-appearance of various cardiovascular disease risk factors constituting the metabolic syndrome (MetS). There is evidence that altered cardiac autonomic function (CAF) may precede the onset of insulin resistance. Exercise training has been shown to improve CAF in different populations, yet little is known regarding the exercise dose response for CAF. The aim of this study was to investigate the impact of different volumes of high-intensity interval training (HIIT) and traditional moderate-intensity continuous training (MICT) on CAF in participants with MetS. METHODS Individuals with MetS (n=56) were randomised into the following 16-week training interventions: i) MICT (n=16, 30min at 60-70%HRpeak, 5×/week); ii) 4HIIT (n=19, 4×4min bouts at 85-95%HRpeak, interspersed with 3min of active recovery at 50-70%HRpeak, 3×/week); or iii) 1HIIT (n=21, 1×4min bout at 85-95%HRpeak, 3×/week). R-R interval recorded for 5min in a supine position at pre- and post-intervention was used to derive linear (SDNN, RMSSD, pNN50, LF, HF, LF/HF) and non-linear (SD1, SD2, Alpha1, Alpha2, SampEn) heart rate variability (HRV) indices as measures of CAF. Group×time interaction effects were examined (ANCOVA) and Eta squared (η2) interaction effect sizes calculated. RESULTS While there were no significant between-group differences in CAF indices, there were small-to-medium group×time interaction effects on SDNN [F(2,52)=0.70, p=0.50, η2=0.02], RMSSD [F(2,52)=1.35, p=0.27, η2=0.03], HF power [F(2,52)=1.27, p=0.29, η2=0.03], SD1 [F(2,52)=0.47, p=0.63, η2=0.01], and SD2 [F(2,52)=0.41, p=0.67, η2=0.01]. The following represent the relative percentage increases across these variables for 4HIIT, MICT, and 1HIIT respectively (SDNN, +30%, +17%, 9%; RMSSD, +30%, +22%, -2%; HF power, +69%, +18%, +7%; SD1, +30%, +22%,-2%; SD2, +22%, +14%, 4%). CONCLUSIONS There were no significant between-group differences for the effects of exercise dose on CAF indices, however; high-volume HIIT demonstrated the greatest magnitude of effect for improving CAF in individuals with MetS.
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7.
12 min/week of high-intensity interval training reduces aortic reservoir pressure in individuals with metabolic syndrome: a randomized trial.
Ramos, JS, Dalleck, LC, Ramos, MV, Borrani, F, Roberts, L, Gomersall, S, Beetham, KS, Dias, KA, Keating, SE, Fassett, RG, et al
Journal of hypertension. 2016;(10):1977-87
Abstract
OBJECTIVE Decreased aortic reservoir function leads to a rise in aortic reservoir pressure that is an independent predictor of cardiovascular events. Although there is evidence that high-intensity interval training (HIIT) would be useful to improve aortic reservoir pressure, the optimal dose of high-intensity exercise to improve aortic reservoir function has yet to be investigated. Therefore, this study compared the effect of different volumes of HIIT and moderate-intensity continuous training (MICT) on aortic reservoir pressure in participants with the metabolic syndrome (MetS). METHODS Fifty individuals with MetS were randomized into one of the following 16-week training programs: MICT [n = 17, 30 min at 60-70% peak heart rate (HRpeak), five times/week]; 4 × 4-min high-intensity interval training (4HIIT) (n = 15, 4 × 4 min bouts at 85-95% HRpeak, interspersed with 3 min of active recovery at 50-70% HRpeak, three times/week); and 1 × 4-min high-intensity interval training (1HIIT) (n = 18, 1 × 4 min bout at 85-95% HRpeak, three times/week). Aortic reservoir pressure was calculated from radial applanation tonometry. RESULTS Although not statistically significant, there was a trend for a small-to-medium group × time interaction effect on aortic reservoir pressure, indicating a positive adaptation following 1HIIT compared with 4HIIT and MICT [F (2,46) = 2.9, P = 0.07, η = 0.06]. This is supported by our within-group analysis wherein only 1HIIT significantly decreased aortic reservoir pressure from pre to postintervention (pre-post: 1HIIT 33 ± 16 to 31 ± 13, P = 0.03; MICT 29 ± 9-28 ± 8, P = 0.78; 4HIIT 28 ± 10-30 ± 9 mmHg, P = 0.10). CONCLUSION Three sessions of 4 min of high-intensity exercise per week (12 min/week) was sufficient to improve aortic reservoir pressure, and thus may be a time-efficient exercise modality for reducing cardiovascular risk in individuals with MetS.
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8.
The effect of different volumes of high-intensity interval training on proinsulin in participants with the metabolic syndrome: a randomised trial.
Ramos, JS, Dalleck, LC, Borrani, F, Mallard, AR, Clark, B, Keating, SE, Fassett, RG, Coombes, JS
Diabetologia. 2016;(11):2308-2320
Abstract
AIMS/HYPOTHESIS The continuous demand for insulin in the face of insulin resistance, coupled with the glucolipotoxic environment associated with the metabolic syndrome (MetS), adversely affects the quality of insulin produced and secreted by the pancreatic beta cells. This is depicted by increased circulating intact proinsulin concentration, which is associated with increased MetS severity and risk of cardiovascular (CV) mortality. High-intensity interval training (HIIT) has been shown to reduce insulin resistance and other CV disease risk factors to a greater degree than moderate-intensity continuous training (MICT). We therefore aimed to investigate the impact of MICT and different volumes of HIIT on circulating intact proinsulin concentration. METHODS This was a substudy of the 'Exercise in prevention of Metabolic Syndrome' (EX-MET) multicentre trial. Sixty-six individuals with MetS were randomised to 16 weeks of: (1) MICT (n = 21, 30 min at 60-70% peak heart rate [HRpeak], five times/week); (2) 4HIIT (n = 22, 4 × 4 min bouts at 85-95% HRpeak, interspersed with 3 min of active recovery at 50-70% HRpeak, three times/week); or (3) 1HIIT (n = 23, 1 × 4 min bout at 85-95% HRpeak, three times/week). A subanalysis investigated the differential impact of these training programmes on intact proinsulin concentration in MetS individuals with type 2 diabetes (MICT, n = 6; 4HIIT, n = 9; 1HIIT, n = 12) and without type 2 diabetes (MICT, n = 15; 4HIIT, n = 13; 1HIIT, n = 11). Intact proinsulin, insulin and C-peptide concentrations were measured in duplicate via ELISA, following a 12 h fast, before and after the exercise programme. Fasting intact proinsulin concentration was also expressed relative to insulin and C-peptide concentrations. RESULTS Following the exercise training, there were no significant (p > 0.05) changes in fasting intact proinsulin concentration indices in all participants (pre- vs post-programme proinsulin, proinsulin:insulin, proinsulin:C-peptide: MICT 19% decrease, 6% increase, 4% increase; 4HIIT 19% decrease, 8% decrease, 11% decrease; 1HIIT 34% increase, 49% increase, 36% increase). In participants who did not have type 2 diabetes, only 4HIIT significantly (p < 0.05) reduced fasting intact proinsulin concentration indices from pre to post intervention (pre- vs post-programme proinsulin, proinsulin:insulin, proinsulin:C-peptide: 4HIIT 32% decrease, 26% decrease, 32% decrease, p < 0.05; 1HIIT, 14% increase, 32% increase, 16% increase, p > 0.05; MICT 27% decrease, 17% decrease, 11% decrease), with a group × time interaction effect, indicating a greater reduction in intact proinsulin indices following 4HIIT compared with MICT and 1HIIT. There were no significant (p > 0.05) changes in intact proinsulin concentration indices in participants with type 2 diabetes. CONCLUSIONS/INTERPRETATION Higher-volume HIIT (4HIIT) improved insulin quality in MetS participants without type 2 diabetes. TRIAL REGISTRATION ClinicalTrials.gov NCT01676870 FUNDING The study was funded by the Norwegian University of Science and Technology and from an unrestricted research grant from the Coca-Cola company. Funding for the collection of physical activity data was derived from a 'UQ New Staff Start Up' grant awarded to B. Clark.