Impact of High-Intensity Interval Training on Cardiometabolic Risk Factors in Youth With Overweight/Obesity: A Systematic Review and Meta-Analysis

BACKGROUND: Childhood and adolescent obesity is a major global health concern that contributes to early atherosclerotic changes and increased cardiometabolic risk. High-intensity interval training (HIIT) has emerged as a time-efficient intervention that can improve cardiometabolic outcomes. However, its effectiveness on cardiometabolic risk markers, including atherosclerotic indicators in children and adolescents with overweight/obesity, remains inconclusive. This systematic review and meta-analysis aimed to analyze the impact of HIIT on cardiometabolic markers in this population. METHODS: A systematic literature search was conducted across PubMed, Web of Science, ScienceDirect, SportDiscus, Cochrane, Embase, and Scopus through June 2025. Randomized and nonrandomized controlled trials examining HIIT interventions lasting ≥2 weeks in apparently healthy children and adolescents (aged 8-19 y) with overweight/obesity (body mass index ≥ 85th percentile) were included. Data were synthesized using Hedges' g to calculate effect sizes, with subgroup analyses comparing HIIT versus moderate-intensity interval training, moderate-intensity continuous training, school-based exercise, and pre-post intervention values. Subgroup meta-analyses for specific comparators were performed when data from more than one study were available. RESULTS: Twenty studies involving 889 participants (M and F) were included. HIIT significantly improved (P ≤ .04) anthropometric indicators (body mass: g = -0.51; body mass index: g = -0.61; body fat percentage: g = -0.69; waist circumference: g = -0.38), blood pressure (systolic: g = -0.63; diastolic: g = -0.42), lipid profile (total cholesterol: g = -0.72; triglycerides: g = -0.63; lipoprotein cholesterol: g = -0.63; high-density lipoprotein cholesterol: g = +0.57), and glycemic markers (glucose: g = -0.27; insulin: g = -0.70; homeostatic model assessment for insulin resistance: g = -0.57), as well as enhancing cardiorespiratory fitness (VO2peak: g = +1.52). Subgroup analyses showed a higher superiority of HIIT on most outcomes compared with moderate-intensity continuous training, but not versus moderate-intensity interval training or school-based exercise. However, comparisons with moderate-intensity interval training and school-based exercise were based on a limited number of studies. Moderate heterogeneity (I2 = 48%-73%) was observed across outcomes. CONCLUSION: Our data show that HIIT is an effective strategy for improving cardiometabolic health in children and adolescents with overweight/obesity as it significantly reduces blood lipids and improves body composition, glycemic control, and cardiorespiratory fitness, with this effect often surpassing that of traditional moderate-intensity continuous training protocols. Further studies should identify optimal HIIT protocols and explore long-term benefits to develop clinical guidelines.