COLLINS, M. A., M. L. MILLARD-STAFFORD, E. M. EVANS, T. K. SNOW, K. J. CURETON, and L. B. ROSSKOPF. Effect of Race and Musculoskeletal Development on the Accuracy of Air Plethysmography. Med. Sci. Sports Exerc., Vol. 36, No. 6, pp. 1070-1077, 2004.
Purpose: The purpose of this study was to determine the effect of race and musculoskeletal development on the accuracy of estimates of body fatness (%fat) via air displacement plethysmography (AP).
Methods: Estimates of %fat were made via AP, hydrostatic weighing (HW), dual-energy x-ray absorptiometry (DXA), and the criterion, a four-component model (4C) in 64 black (B) and white (W) men, who were either resistance trained (RT) or served as controls (C).
Results: Based on a three-way ANOVA, there were no statistically significant three-way or race × musculoskeletal development interactions. There was no main effect of race on the validity of estimating %fat by AP; the mean bias between %FatAP and %Fat4C was similar for B (3.6% body fat) and W (3.7%). In addition, the density of the fat-free mass (Dffm) for B (1.098 ± 0.002 g·mL-1) was not different than 1.10 g·mL-1. There was a significant effect of musculoskeletal development on the validity of the estimation of %fat from AP; the mean difference in %fat between %FatAP and %Fat4C was less in RT (1.5% body fat) than in C (5.3%), but a large SEE of 5.5% was observed for RT. A significant (P < 0.05) correlation was found between the mean bias between methods and body volume (-0.44) and mesomorphy (-0.55).
Conclusions: Race does not affect the accuracy of estimating %fat by AP. Race-specific equations estimating %fat via densitometry (e.g., AP, HW) such as the Schutte are not justified, because Dffm is not greater than 1.10 g·mL- 1. Estimation of %fat via AP is more accurate in larger individuals with high musculoskeletal development as a group, but individual results are highly variable.