Nutrition and Health Sciences, Department of


Document Type


Date of this Version



Accepted for Journal of Strength and Conditioning Research.
Published Ahead of PrintNovember 2017.

DOI: 10.1519/JSC.0000000000002347


Copyright © 2017 National Strength and Conditioning Association. Published by Wolters Kluwer Health. Used by permission.


The purpose of this study was to evaluate stature (HT), weight (WT), body mass index (BMI), and obesity prevalence based on BMI categories in a large sample (n = 7,175) of high school American football players enrolled as freshmen, sophomores, or juniors. Players were categorized by their positions: offensive linemen (OL), defensive linemen (DL), tight end (TE), defensive end (DE), linebacker (LB), running back (RB), quarterback (QB), defensive back (DB), and wide receiver (WR). HT, WT, and BMI increased as grade increased among all positions. OL and DL had the greatest HT, WT, and BMI (p≤0.05). Obesity prevalence was greatest in OL and DL. When accounting for age-related increases in BMI, WT increased to a greater degree than HT. If HT is an indirect indicator of skeletal size, while WT is more influenced by soft tissue, then the age-related BMI increases in the present study may be largely accounted for by soft tissue changes rather than skeletal growth. Even though obesity prevalence in OL (94.5%) and DL (78.4%) positions was greater than all other positions as determined from BMI, it is impossible to know the allocations of fat-free and fat mass—particularly in American football athletes. If obesity continues to be defined as an unhealthy accumulation of fat, then athletes who may have a greater relative proportion of lean soft tissue should not be classified as obese using BMI (WT÷HT²). More sophisticated, reliable, and sensitive measure of body composition, such as skinfolds, may be more appropriate field measurements.