title: The estimation of the fat free mass index in athletes.
abstract: OBJECTIVE
  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/ 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).
  
  
  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/ 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.
authors.affiliation: Department of Health and Exercise Science, The University of Oklahoma, Norman, USA ; Department of Health Sciences and Human Performance, University of Tampa, Tampa, USA ; Department of Nutritional Sciences, The University of Oklahoma Health Sciences Center, Oklahoma City, USA ; Department of Health, Human Performance, and Recreation. Southeast Missouri State University, Cape Girardeau, USA ; Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, USA.
authors.forename: Jeremy P
authors.initials: JP
authors.lastname: Loenneke
authors.forename: Jacob M
authors.initials: JM
authors.lastname: Wilson
authors.forename: Mandy E
authors.initials: ME
authors.lastname: Wray
authors.forename: Jeremy T
authors.initials: JT
authors.lastname: Barnes
authors.forename: Monica L
authors.initials: ML
authors.lastname: Kearney
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Pujol