High-intensity interval training is not superior to continuous aerobic training in reducing body fat: A systematic review and meta-analysis of randomized clinical trials.

Background/Objective: Guidelines on obesity management reinforce regular exercise to reduce body fat. Exercise modalities, including high-intensity interval training (HIIT), appear to produce a similar effect to continuous aerobic training (CAT) on body fat. However, they have not addressed the chronic effect of HIIT vs. CAT on body fat assessed by dual energy X-ray absorptiometry (DEXA). Thus, we compared the effectiveness of CAT vs. HIIT protocols on body fat (absolute or relative) (%BF) and abdominal visceral fat reduction, assessed by DEXA, in adults with overweight and obesity. Methods: We conducted a systematic review and meta-analysis of randomized clinical trials (RCTs) including both female or male adults with excess body weight. We performed searches in the databases MEDLINE (PubMed), EMBASE, Scopus, LILACS, Web of Science and Cochrane. Results: In our analysis (11 RCTs), we found no greater benefit on %BF of HIIT vs. CAT (MD -0.55%, 95% CI -1.42 to 0.31; p = 0.209). As for abdominal visceral fat, no training modality was superior (SMD: -0.05, 95% CI -0.29 to 0.19; p = 0.997). Regarding secondary outcomes (body weight, BMI, VO2 max, glycemic and lipid profiles), HIIT shows greater benefit than CAT in increasing VO2 max and fasting blood glucose and reducing total cholesterol. Conclusion: HIIT is not superior to CAT in reducing %BF or abdominal visceral fat in individuals characterized by excess weight. However, HIIT showed beneficial effects on cardiorespiratory fitness, total cholesterol and fasting blood glucose when compared to CAT.

Effect of aerobic and resistance exercise training on endothelial function in individuals with overweight and obesity: a systematic review with meta-analysis of randomized clinical trials.

The objective of this systematic review was to examine the effects of exercise training on endothelial function in individuals with overweight and obesity. Our review study included only randomized controlled trials (RCTs) involving adults (≥ 18 years of age) with body mass index (BMI) ≥ 25.0 kg/m2. Our search was conducted in the electronic bases MEDLINE (PubMed), Cochrane, LILACS and EMBASE and in the gray literature. We performed random-effects analyses for effect estimates and used 95% prediction intervals (95% PI) for estimating the uncertainty of the study results. There were selected 10 RCTs involving 14 groups (n = 400). The quality assessment of studies using Cochrane risk-of-bias 2 (RoB 2) tool identified some concerns. Exercise training resulted in improved flow-mediated dilation (FMD) in individuals with overweight and obesity (p < 0.001) compared to the no-exercise control group. This effect of training modalities on FMD was seen for aerobic training (p < 0.001) but not for resistance training (p = 0.051). There was no difference in FMD in response to exercise training by BMI classification (overweight, obesity, overweight + obesity), p = 0.793. The present results are consistent with the notion that aerobic exercise training elicits favorable adaptations in endothelial function in individuals with overweight and obesity. Our findings should be interpreted with caution because of the small number of studies included in this review.

Effect of isometric exercise on blood pressure in prehypertensive and hypertensive individuals: protocol for a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Systemic arterial hypertension (HTN) is the leading risk factor of cardiovascular disease death. Lifestyle changes are key for the prevention and management of HTN. Regular aerobic exercise training is recommended as part of the management of HTN, and dynamic resistance exercise should be prescribed as an adjuvant to aerobic training. Recent evidence points to the potential benefits of isometric resistance training in reducing blood pressure (BP). Yet, the hypotensive effect of isometric exercise in prehypertensive and hypertensive individuals is not fully understood. Thus, we will examine the effect of isometric exercise in prehypertensive and hypertensive individuals through a systematic review and meta-analysis. METHODS: Our systematic review study will include randomized controlled trials (RCTs) selected from the electronic databases MEDLINE (PubMed), Cochrane, LILACS, EMBASE, Web of Science, and PEDro published in English, Spanish, and Portuguese languages. We will follow the PRISMA-P (Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols) and PICOS framework. Our search will involve studies with both male and female participants aged 18 years or more diagnosed with prehypertension or HTN performing one session of isometric exercise (acute effect) or isometric exercise training (chronic effect) compared to a control group (no exercise). We will use the Cochrane Risk of Bias 2 (RoB 2) tool to evaluate the quality of the studies and RStudio software (v1.3.959 for Windows) for statistical analyses. DISCUSSION: A meta-analysis of a homogeneous sample of prehypertensive and hypertensive individuals involving isometric handgrip exercise alone can further support previous findings and improve our understanding and recommendations for the management of these populations. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020213081.