Effects and Dose-Response Relationship of High-Intensity Interval Training on Cardiometabolic Risk in Individuals With Overweight and Obesity: A Systematic Review and Meta-Analysis.

Abstract

Individuals with overweight and obesity exhibit elevated cardiometabolic risks. While high-intensity interval training (HIIT) demonstrates potential in improving cardiometabolic health, evidence-based recommendations for optimal HIIT protocols remain uncertain. This study aimed to explore the effects of HIIT on cardiometabolic risk in individuals with overweight and obesity and to characterize dose-response relationships of HIIT programming variables. A systematic search of five databases (PubMed, Embase, Cochrane Library, Web of Science, Scopus) identified 19 randomized controlled trials comprising 24 intervention groups. The risk of bias was evaluated using the Cochrane Collaboration Tool. Relevant data were extracted, and a meta-analysis was performed using RevMan5.4 software. Meta-analysis demonstrated that HIIT significantly improved cardiorespiratory fitness (CRF) (standardized mean difference [SMD] = 1.18) and reduced TG (SMD = -0.40) compared to nonexercising controls. Subgroup analyses revealed greater CRF improvements with interventions ≥ 8 weeks, work/rest intervals ≥ 90 s, and high-volume long-interval protocols. Total cholesterol (TC) reductions were significant under work/rest intervals ≥ 90 s (SMD = -1.67) and high-volume protocols (SMD = -2.15). Maximal triglycerides (TG) benefits occurred with work/rest intervals ≥ 90 s (SMD = -0.64) and high-volume protocols (SMD = -0.72). However, HIIT showed no significant effects on body composition, blood pressure, glucose, or high-density lipoprotein/low-density lipoprotein cholesterol. HIIT is an effective strategy to reduce cardiometabolic risk (CRF, lipid metabolism) in individuals with overweight and obesity, with a preliminary dose-response relationship observed between training variables and outcomes. Future studies should optimize protocols and confirm sustained benefits.