Evaluation of leg-to-leg BIA in assessing body composition of high-school wrestlers.
OBJECTIVE
To evaluate the accuracy of leg-to-leg bioelectrical impedance analysis (BIA) in assessing fat-free mass (FFM) using the TBF-300WA in comparison with hydrostatic weighing (HW) and skinfolds (SK) in high-school (HS) wrestlers in a hydrated state.


METHODS
Body composition was determined by BIA, HW, and three-site SK in 129 HS wrestlers (mean +/- SD, age: 15.5 +/- 1.3, height 1.70 +/- 0.08 m, body mass 65.6 +/- 13.1 kg). For all methods, body density (Db) was converted to percent body fat (%BF) using the Brozek equation. Hydration state was quantified by evaluating urine specific gravity.


RESULTS
There were no significant differences for estimated FFM between BIA (56.9 +/- 8.4 kg) and HW (56.2 +/- 9.9 kg) or between SK (56.1 +/- 8.9 kg) and HW. The standard errors of estimate for FFM with HW as the reference method were 3.64 kg for BIA and 1.97 kg for SK. Significant correlations were found for FFM between HW and BIA (r = 0.93, P < 0.001), and between HW and SK (r = 0.98, P < 0.001). The FFM difference between BIA and HW was significantly correlated with the FFM average of the two methods (r = -0.39, P < 0.001). The FFM difference between SK and HW was also significantly correlated with the FFM average (r = -0.44, P < 0.001).


CONCLUSIONS
This study demonstrates that SK should be considered as the preferred field method of estimating the FFM of HS wrestlers because of its greater individual precision than the leg-to-leg BIA method. Although the BIA is an attractive assessment tool and easy to use, it should be recommended as an alternative to the SK method only when trained skinfold technicians are not available.
Utter
Alan C
AC
Department of Health, Leisure, and Exercise Science, Appalachian State University, Boone, NC 28608, USA. utterac@appstate.edu
Nieman
David C
DC
Mulford
Gregory J
GJ
Tobin
Richard
R
Schumm
Sean
S
McInnis
Tim
T
Monk
James R
JR
D000293:Adolescent; D001823:Body Composition; D017097:Electric Impedance; D006801:Humans; D007866:Leg; D008297:Male; D009657:North Carolina; D014952:Wrestling