Which Body Density Equations Calculate Body Fat Percentage Better in Olympic Wrestlers?-Comparison Study with Air Displacement Plethysmography

Abstract

Although skinfold-derived equations seem to be practical for field application in estimating body fat percentage (BF%) and minimum body mass in Olympic wrestlers, prediction equations applied first need to be cross-validated in Olympic wrestlers to define the best prediction equation. This study aimed to evaluate the most accurate field method to predict BF% in Olympic wrestlers compared to BF% estimated by air displacement plethysmography (ADP). Sixty-one male (body mass 72.4 ± 13.5 kg; height 170.3 ± 7.0 cm; body mass index (BMI) 24.9 ± 3.5 kg.m^-2; BF% 8.5 ± 4.9%) and twenty-five female wrestlers (body mass 60.3 ± 9.9 kg; height 161.3 ± 7.1 cm; BMI 23.1 ± 2.5 kg.m^-2; BF% 18.7 ± 4.7%) undertook body composition assessments including ADP and nine-site skinfold measurements. Correlations, bias, limits of agreement, and standardized differences between alterations in BF% measured by ADP and other prediction equations were evaluated to validate measures, and multiple regression analyses to develop an Olympic wrestlers-specific prediction formula. The Stewart and Hannan equation for male wrestlers and the Durnin and Womersley equation for female wrestlers provided the most accurate BF% compared to the measured BF% by ADP, with the lowest bias and presented no significant differences between the measured and predicted BF%. A new prediction equation was developed using only abdominal skinfold and sex as variables, predicting 83.2% of the variance. The findings suggest the use of the new wrestler-specific prediction equation proposed in the study as a valid and accurate alternative to ADP to quantify BF% among Olympic wrestlers.

Keywords: BOD POD; anthropometry; body composition; fat mass; skinfolds; wrestling.

Figure 1

Bland–Altman plots for BODPOD and the prediction equations for wrestlers aged below 18. The dash-dotted line represents the mean difference (BIAS) between methods. The upper and lower dashed lines represent the 95% limits of agreement. The solid line represents the zero line. (A) Represents Bland-Altman plots of male wrestlers. (B) Shows Bland-Altman plots of female wrestlers.

Figure 2

Bland–Altman plots for BODPOD and the prediction equations for wrestlers aged above 18. Bland–Altman plots for BODPOD and the methods for the subjects. The dash-dotted line represents the mean difference (BIAS) between methods. The upper and lower dashed lines represent the 95% limits of agreement. The solid line represents the zero line. (A) Represents Bland-Altman plots of male wrestlers. (B) Shows Bland-Altman plots of female wrestlers.