Effects of high-intensity interval training on body composition, cardiorespiratory fitness, and selected lipid outcomes in adult women with overweight or obesity: a systematic review and meta-analysis.

Objective: This systematic review and meta-analysis aimed to evaluate the effects of high-intensity interval training (HIIT) on body composition, cardiorespiratory fitness, and selected lipid outcomes in adult women with overweight, obesity, or normal-weight obesity.

Methods: This review followed the PRISMA guidelines and was registered in PROSPERO (CRD420261394616). PubMed, Web of Science Core Collection, Embase, and MEDLINE via Ovid were searched from database inception to 26 July 2026. Eligible studies were randomized controlled trials involving adult women with overweight, obesity, or normal-weight obesity and comparing HIIT with control conditions without structured exercise. Outcomes included body weight (BW), body mass index (BMI), body fat percentage (BF%), fat mass (FM), maximal or peak oxygen uptake (VO₂max/VO₂peak), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), and triglycerides (TG). Hedges' g with 95% confidence intervals (CIs) was used as the pooled effect measure, and random-effects meta-analyses were performed.

Results: Fifteen randomized controlled trials were included. Compared with controls without structured exercise, HIIT significantly reduced BW (g = -0.33, 95% CI -0.58 to -0.08; P = 0.01), BMI (g = -0.56, 95% CI -0.95 to -0.17; P< 0.01), BF% (g = -0.76, 95% CI -1.35 to -0.17; P = 0.01), and FM (g = -0.66, 95% CI -1.11 to -0.20; P< 0.01), and significantly improved VO₂max/VO₂peak (g = 1.09, 95% CI 0.70 to 1.47; P< 0.01). HIIT also increased HDL-C and reduced LDL-C, whereas effects on TC and TG were not statistically significant. Subgroup and meta-regression analyses were exploratory. Evidence certainty ranged from low to very low.

Conclusions: Current randomized evidence suggests that, compared with controls without structured exercise, HIIT may favor adiposity-related body-composition outcomes and cardiorespiratory fitness in adult women with overweight, obesity, or normal-weight obesity, whereas its effects on selected lipid outcomes remain uncertain. The review did not systematically evaluate other cardiometabolic outcomes, including blood pressure, insulin resistance, glycemic control, or inflammatory markers. The findings should be interpreted cautiously because of the limited number of studies, small sample sizes, between-study heterogeneity, and low to very low certainty of evidence.

Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/, identifier CRD420261394616.