Effects of water aerobics on body composition in obesity and overweight people: a systematic review and meta-analysis.

Objectives: Obesity and overweight significantly impact public health. The benefits of water aerobics (WAs) have been shown in obesity and overweight people, but the effects of WAs on body composition improvement are still unclear.

Design: Systematic review and meta-analysis.

Data Sources: A systematic literature search was conducted on 16 November 2024, across the PubMed MEDLINE, Ovid MEDLINE, Embase, Scopus, Web of Science and the Cochrane Library.

Eligibility Criteria For Selecting Studies: Only randomised controlled trials (RCTs) were included, which were independently screened by two researchers. All RCTs on WAs that evaluated the anthropometric and body composition parameters of overweight and obesity subjects were included. Eligible studies were reported following the Reporting Items for Systematic Reviews and Meta-Analysis statement.

Data Extraction And Synthesis: All process were independently screened by two researchers (ZD, HZ). A fixed-effects or random-effects model was chosen based on the heterogeneity of the studies. The risk of bias in the included studies was assessed using the Risk of Bias V.2.0 tool, and sensitivity and subgroup analyses were conducted for outcome indicators. The quality of evidence for each outcome was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system.

Results: A total of 10 studies involving 286 participants were included. Sensitivity analyses were performed for percent body fat (PBF) with high heterogeneity, and the results were robust. WAs were able to reduce body weight (BW) (weighted mean differences (WMD)=-2.69, 95% CI -4.10 to -1.27, p<0.05, I=0.0%) and waist circumference (WC) (WMD=-2.75, 95% CI -4.41 to -1.09, p<0.05, I=27.0%), but the effect on other body indicators was not significant. The GRADE assessment revealed that the certainty of evidence was low for body mass index, lean mass, fat mass, waist-hip ratio and hip circumference and very low for PBF. In contrast, the certainty of evidence for BW and WC was moderate.

Conclusion: For the obesity and overweight people, WAs interventions over 10 weeks (ie, 12 weeks) reduced BW and WC, with more significant effects in women and greater improvements in body composition in middle-aged and older adults (average age ≥45 years). The moderate certainty of evidence for BW and WC, as assessed using the GRADE framework, indicates that these findings are robust.

Prospero Registration Number: CRD42023466969.