Longitudinal Body Composition Changes in NCAA Division I College Football Players

• Published in: Journal of strength and conditioning research 2017-01, Vol.31 (1), p.1-8
• Main Authors: Trexler, Eric T, Smith-Ryan, Abbie E, Mann, J Bryan, Ivey, Pat A, Hirsch, Katie R, Mock, Meredith G
• Format: Article
• Language: English
• Subjects: Absorptiometry, Photon; Adolescent; Adult; Athletes; Body Composition - physiology; Body Weights and Measures; Bone Density; College football; Football - physiology; Human body; Human performance; Humans; Male; Physical fitness; Seasons; Universities; Young Adult
• ISSN: 1064-8011; 1533-4287
• DOI: 10.1519/JSC.0000000000001486

ABSTRACTTrexler, ET, Smith-Ryan, AE, Mann, JB, Ivey, PA, Hirsch, KR, and Mock, MG. Longitudinal body composition changes in NCAA Division I college football players. J Strength Cond Res 31(1)1–8, 2017—Many athletes seek to optimize body composition to fit the physical demands of their sport. American football requires a unique combination of size, speed, and power. The purpose of the current study was to evaluate longitudinal changes in body composition in Division I collegiate football players. For 57 players (mean ± SD, age = 19.5 ± 0.9 years, height = 186.9 ± 5.7 cm, weight = 107.7 ± 19.1 kg), body composition was assessed via dual-energy x-ray absorptiometry in the off-season (March-Pre), end of off-season (May), mid-July (Pre-Season), and the following March (March-Post). Outcome variables included weight, body fat percentage (BF%), fat mass, lean mass (LM), android and gynoid (GYN) fat, bone mineral content (BMC), and bone mineral density (BMD). For a subset of athletes (n = 13 out of 57), changes over a 4-year playing career were evaluated with measurements taken every March. Throughout a single year, favorable changes were observed for BF% (Δ = −1.3 ± 2.5%), LM (Δ = 2.8 ± 2.8 kg), GYN (Δ = −1.5 ± 3.0%), BMC (Δ = 0.06 ± 0.14 kg), and BMD (Δ = 0.015 ± 0.027 g·cm, all p ≤ 0.05). Across 4 years, weight increased significantly (Δ = 6.6 ± 4.1 kg) and favorable changes were observed for LM (Δ = 4.3 ± 3.0 kg), BMC (Δ = 0.18 ± 0.17 kg), and BMD (Δ = 0.033 ± 0.039 g·cm, all p ≤ 0.05). Similar patterns in body composition changes were observed for linemen and non-linemen. Results indicate that well-trained collegiate football players at high levels of competition can achieve favorable changes in body composition, even late in the career, which may confer benefits for performance and injury prevention.