DXA, DENSITOMETRY, TANITA, SKINFOLDS, AND MULTICOMPONENT ESTIMATES OF BODY COMPOSITION IN HYDRATED AND DEHYDRATED ATHLETES

Abstract

The purpose of the study was to compare methods for estimating body fat in hydrated and dehydrated college athletes. Hydration was assessed by urine specific gravity (USG) per NCAA guidelines. The methods included dual energy x-ray absorptiometry (DXA, Norland XR-36), Tanita BIA (TBF-300), the Lohman (1981) skinfold (SF) equation, and hydrostatic weighing (HW). The criterion %FAT was calculated with a multi-component (MULTI) model that adjusts for individual variation in body water and bone mineral content. Bone mineral from DXA and total body water by deuterium dilution were used to correct body density according to the Selinger (1977) four compartment formula. Subjects were division I college athletes from the University of Wisconsin (mean ± SD; n = 28, age = 19.71 ± 1.21yr, ht = 177.57 ± 7.92cm, wt = 74.50 ± 8.70kg). Mean %FAT values, correlation (r) and total error (TE) are shown for hydrated (H, n = 14, USG ≤ 1.020) and dehydrated (D, n = 14, USG > 1.020) athletes: No significant difference was seen between HW, SF, Tanita and the criterion in the athletes with USG ≤ 1.020. No significant difference was seen between the methods when USG > 1.020. When using a MULTI criterion, the lowest correlation and largest TE were seen in Tanita when the athletes were considered dehydrated by the NCAA standards for USG in this sample of college athletes.Table: No Caption Avilable