Muscle characteristics and body composition of NCAA division I football players

The purpose of this study was to investigate muscle cross sectional area (mCSA) and echo intensity (EI) of the vastus lateralis (VL) and body composition of Division I football players. Sixty-nine players were stratified by position, race, year, and starter status. Muscle CSA and EI were determined from a B-mode ultrasound panoramic scan of the VL using Image-J software. Fat mass (FM), lean mass (LM), and body fat (%fat) were determined using dual-energy x-ray absorptiometry. Measures of mCSA (38.7+/-6.6 cm2, %fat (17.9+/-4.6 %), LM (81.3+/-11.8 kg), and FM (19.5+/-8.7 kg) were found to be significantly different across position (p<0.05), likely due to the differences in position-specific tasks. Offensive and defensive linemen were not significantly different (p>0.05), and had the greatest mCSA (44.4 cm2), %fat (23.4%), LM (96.4 kg) and FM (30.9 kg) values in comparison to all other positions. No differences (p=0.161) were observed between positions for EI.