Validation of air displacement plethysmography for assessing body composition

Publisher Website
Google Scholar
Abstract
WAGNER, D. R., V. H. HEYWARD, and A. L. GIBSON. Validation of air displacement plethysmography for assessing body composition. Med. Sci. Sports Exerc., Vol. 32, No. 7, pp. 1339–1344, 2000. The purpose of this study was to verify the validity of an air displacement plethysmography device (Bod Pod®) for estimating body density (Db). The Db from the Bod Pod (DbBP) was compared with the Db from hydrostatic weighing (DbHW) at residual lung volume in a heterogeneous sample of 30 black men who varied in age (32.0 ± 7.7 yr), height (180.3 ± 7.5 cm), body mass (84.2 ± 15.0 kg), body fatness (16.1 ± 7.5%), and self-reported physical activity level and socioeconomic status. The Db for each method was converted to relative body fat (%BF) using race-specific conversion formulas and subsequently compared with %BF obtained from dual-energy x-ray absorptiometry (%BFDXA). Linear regression, using DbHW as the dependent variable and DbBP as the predictor, produced an R2 = 0.84 and SEE = 0.00721 g·cc−1. However, the mean difference between the two methods (0.00450 ± 0.00718 g·cc−1) was significant (P P The Bod Pod significantly and systematically underestimated Db, resulting in an overestimation of %BF. More cross-validation research is needed before recommending the Bod Pod as a reference method.