Comparison of measured and predicted residual, lung volume in determining body composition of collegiate wrestlers

This investigation compared percent fat obtained via underwater weighing using measured and predicted residual lung volume (RLV) in euhydrated and hypehydrated collegiate wrestlers (N = 67). RLV was measured using [O.sub.2] rebreathing or [0.sub.2] dilution and predicted using 3 equations--Equation 1:(0.019 x height [cm]) + (0.0115 x age [years])--2.24; Equation 2: (0.017 x age [years]) + (0.06858 x height [in.])--3.477; and Equation 3: (0.0275 age [years]) + (0.0189 height [cm])--2.6139. Percent fat determined using RLV Equation 2 did not differ from the value obtained using measured RLV in the euhydrated (10.9 (+ or -] 5.1 vs. 11.5 [+ or -] 5.6% fat) or hypohydrated (10.8 [+ or -] 5.1 vs. 12.3 [+ or -] 5.6% fat) trials. All other percent fat values differed (p < 0.05) from the value obtained using measured RLV in euhydrated subjects. The use of RLV Equation 2 may be a practical alternative to measured RLV in determining percent fat in euhydrated and hypohydrated collegiate wrestlers. KEY WORDS. percent fat, hydration status, hydrostatic weighing