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Evaluation of Ultrasound in Assessing Body Composition of High School Wrestlers


Medicine & Science in Sports & Exercise: May 2008 - Volume 40 - Issue 5 - p 943-949
doi: 10.1249/MSS.0b013e318163f29e
APPLIED SCIENCES: Physical Fitness and Performance

Purpose: To evaluate the accuracy of ultrasound (ULTRA) in assessing fat-free mass (FFM) in comparison with hydrostatic weighing (HW) and skinfolds (SK) in high school wrestlers in a hydrated state.

Methods: Body composition was determined by ULTRA, HW, and three-site SK in 70 high school wrestlers (mean ± SD: age, 15.5 ± 1.5; height, 1.60 ± 0.08 m; body mass, 65.8 ± 12.7 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 ULTRA (57.2 ± 9.7 kg) and HW (57.0 ± 9.9 kg); however, SK (54.9 ± 8.8 kg) were significantly different from HW. The standard errors of estimate for FFM with HW as the reference method were 2.40 kg for ULTRA and 2.74 kg for SK. Significant correlations were found for FFM between HW and ULTRA (r = 0.97, P < 0.001) and between HW and SK (r = 0.96, P < 0.001). A systematic bias was found for SK, as the difference between SK and HW significantly correlated with the FFM average of the two methods (r = −0.38, P < 0.001). This systematic bias was not found for ULTRA (r = − 0.07).

Conclusions: This study demonstrates that ULTRA provides similar estimates of FFM when compared with HW in a heterogeneous high school wrestling population during a hydrated state. ULTRA should be considered as an alternative field-based method of estimating the FFM of high school wrestlers.

Department of Health, Leisure, and Exercise Science, Appalachian State University, Boone, NC

Address for correspondence: Alan C. Utter, Ph.D., MPH, FACSM, Department of Health, Leisure, and Exercise Science, Appalachian State University, Boone, NC 28608; E-mail:

Submitted for publication August 2007.

Accepted for publication December 2007.

©2008The American College of Sports Medicine