A comparison of methods for the estimation of body composition in highly trained wheelchair games players

The purpose of this study was to assess the agreement in body composition measurements of wheelchair athletes using skinfolds, bioimpedance analysis (BIA) and air displacement plethysmography (ADP) with the criterion method of dual-energy X-ray absorptiometry (DXA). A secondary objective was to develop new skinfold prediction equations to estimate út for this sample. Thirty wheelchair games players were recruited and the body composition outcomes of BIA, ADP, and skinfolds were compared to the DXA outcomes by a paired-samples t-test (systematic bias), intraclass correlation (ICC, relative agreement) and Bland-Altman plots (absolute agreement). Regression models to predict the út as measured by DXA by the sum of skinfolds or BIA were calculated. Results showed that the predictions of út when using BIA, ADP or skinfolds systematically underestimated the út mass as measured by the DXA. All ICC values, except for the measurement of fat (kg) by ADP (ICC=0.702), were below 0.7. New prediction models found the Σ7 skinfolds and calf circumference as the best model to predict út (R2=0.84). In conclusion, BIA, ADP and existing skinfolds equations should be used with caution when estimating út of wheelchair athletes with substantial body asymmetry, lower body muscular atrophy and upper body muscular development.