Fat-Free Mass Index in NCAA Division I and II Collegiate American Football Players. Academic Article uri icon

abstract

  • Fat-free mass index (FFMI) is a height-adjusted assessment of fat-free mass (FFM), with previous research suggesting a natural upper limit of 25 kgm in resistance trained male athletes. The current study evaluated upper limits for FFMI in collegiate American football players (n = 235) and evaluated differences between positions, divisions, and age groups. The sample consisted of 2 National Collegiate Athletic Association Division I teams (n = 78, n = 69) and 1 Division II team (n = 88). Body composition was assessed via dual-energy x-ray absorptiometry and used to calculate FFMI; linear regression was used to normalize values to a height of 180 cm. Sixty-two participants (26.4%) had height-adjusted FFMI values above 25 kgm (mean = 23.7 2.1 kgm; 97.5th percentile = 28.1 kgm). Differences were observed among position groups (p < 0.001; = 0.25), with highest values observed in offensive linemen (OL) and defensive linemen (DL) and lowest values observed in offensive and defensive backs. Fat-free mass index was higher in Division I teams than Division II team (24.3 1.8 kgm vs. 23.4 1.8 kgm; p < 0.001; d = 0.49). Fat-free mass index did not differ between age groups. Upper limit estimations for FFMI seem to vary by position; although the 97.5th percentile (28.1 kgm) may represent a more suitable upper limit for the college football population as a whole, this value was exceeded by 6 linemen (3 OL and 3 DL), with a maximal observed value of 31.7 kgm. Football practitioners may use FFMI to evaluate an individual's capacity for additional FFM accretion, suitability for a specific position, potential for switching positions, and overall recruiting assessment.

published proceedings

  • J Strength Cond Res

altmetric score

  • 5.35

author list (cited authors)

  • Trexler, E. T., Smith-Ryan, A. E., Blue, M., Schumacher, R. M., Mayhew, J. L., Mann, J. B., ... Mock, M. G.

citation count

  • 19

complete list of authors

  • Trexler, Eric T||Smith-Ryan, Abbie E||Blue, Malia NM||Schumacher, Richard M||Mayhew, Jerry L||Mann, J Bryan||Ivey, Pat A||Hirsch, Katie R||Mock, Meredith G

publication date

  • October 2017