Body fat of competitive volleyball players: a systematic review with meta-analysis

Background: Reference values of body fat for competitive volleyball players are lacking, making it difficult to interpret measurement results. This review systematically summarized published data on the relative body fat of volleyball players and calculated potential differences between sex, measurement method, and competitive level. Methods: The protocol followed the Preferred Reported Items for Systematic Reviews and Meta-Analysis guidelines. The literature search was conducted using five electronic databases to retrieve all relevant publications from January 1, 2010, to July 1, 2021. The 63 studies including 2607 players that met the inclusion criteria were analyzed using random-effects models. Data were reported as pooled mean body fat with 95% confidence intervals. Results: Body fat for males and females was 12.8% (11.9–13.8%) and 22.8% (21.9–23.7%), respectively. Body fat was 18.3% (16.3–20.4%) measured via skinfolds, 18.4% (15.6–21.2%) via bioelectrical impedance analysis, 24.2% (20.4–28.0%) via dual-energy x-ray absorptiometry and 21.6% (17.4–25.8%) via densitometry. Regional, national, and international-level players had body fat values of 19.5% (17.8–21.2%), 20.3% (18.6–22.0%), and 17.9% (15.7–20.4%), respectively. When the meta-regression was adjusted for the variables sex, measurement method, and competitive level, a significant difference between sex (p < 0.001), dual-energy x-ray absorptiometry and skinfolds (p = 0.02), and national and international-level players (p = 0.02) was found. However, sensitivity analysis revealed that findings regarding measurement method and competitive level were not robust and should, therefore, be interpreted with caution. Conclusions: Despite the limitations of published data, this meta-analysis provided pooled values for body fat of male and female volleyball players for different competitive levels and measurement methods.