estimation of the fat free mass index in athletes

ABSTRACT

The purpose of this investigation was to compare a practical measurement of fat free mass index [FFMI] from bioelectrical impedance analysis [BIA] to the dual energy X-ray absorptiometry [DEXA] value in collegiate athletes. Thirty-three male baseball players and 16 female gymnasts volunteered to participate in this study during their respective pre-season. Subjects visited the laboratory once and had their measurements taken in the following order weight, height, DEXA, and Omron HBF-500. The BIA device investigated was not a valid estimate of FFMI when compared to the DEXA. The TE was 0.93 kg/ m[2] for males and 0.78 kg/ m[2] for females. There were also significant mean differences between the BIA prediction and the DEXA value for males [BIA=20.6 kg/m[2] vs. DEXA=21.1 kg/m[2], P=0.007] and females [BIA=16.2 kg/m[2] vs. DEXA=17.5 kg/m[2], P=0.001]. The BIA device investigated in this study did not provide a valid estimate of FFMI in male and female collegiate athletes. Although there was a general tendency for the BIA to underestimate FFMI compared to DEXA, 98% of the estimates were within plus or minus 2 kg/ m[2]. Therefore, while slightly biased, BIA may provide a reasonable [+/- 2 kg/ m[2]] estimate of nutritional status for practitioners who are unable able to afford more expensive equipment