The Estimation of the Fat Free Mass Index in Athletes


Jeremy P. Loenneke 5 , * , Jacob M. Wilson 5 , Mandy E. Wray 5 , Jeremy T. Barnes 5 , Monica L. Kearney 5 , Thomas J. Pujol 5

5 Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, USA

How to Cite: Loenneke J P, Wilson J M, Wray M E, Barnes J T, Kearney M L, et al. The Estimation of the Fat Free Mass Index in Athletes, Asian J Sports Med. Online ahead of Print ; 3(3):34691. doi: 10.5812/asjsm.34691.


Asian Journal of Sports Medicine: 3 (3); 200-203
Published Online: August 31, 2012
Article Type: Research Article
Received: March 8, 2012
Accepted: June 23, 2012


Purpose: 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.

Methods: 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.

Results: The BIA device investigated was not a valid estimate of FFMI when compared to the DEXA. The TE was 0.93 kg/ m2 for males and 0.78 kg/ m2 for females. There were also significant mean differences between the BIA prediction and the DEXA value for males (BIA=20.6 kg/m2 vs. DEXA=21.1 kg/m2, P=0.007) and females (BIA=16.2 kg/m2 vs. DEXA=17.5 kg/m2, P=0.001).

Conclusions: 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/ m2. Therefore, while slightly biased, BIA may provide a reasonable ( 2 kg/ m2) estimate of nutritional status for practitioners who are unable able to afford more expensive equipment.

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