Introduction: The purpose of this investigation was to characterize the bone mineral density in a wide variety of competitive athletes.

Methods: A cohort of 135 athletes was assessed for body composition via dual-energy x-ray absorptiometry (DXA). These included professional mixed martial arts fighters (MMA), elite stand-up paddlers, collegiate football players, collegiate swimmers, collegiate track and field athletes, collegiate and world-class distance runners as well as a group of men and women who participated in regular heavy resistance training.

Results: In general, bone mineral density (BMD) as determined by the T-score was highest in mixed martial arts fighters (T-score = 3.1 ± 0.9) and football players (T-score = 2.7 ± 0.7) followed by resistance-trained (RT) males (T-score = 1.9 ± 1.2). RT males had a greater average T-score than RT females (T-score 1.5 ± 1.3). Based on the data from this investigation, we conclude that RT males have greater BMD as determined by the T-score than RT females. Also, MMA fighters and football players are unique in that they tend to demonstrate very high BMD (1.57 ± 0.10 and 1.60 ± 0.12 g/cm2 , respectively) with a concomitantly high T-score.

Conclusions: It is evident that the high-impact nature of football and MMA competition is conducive to producing very high bone mineral densities. However, inasmuch as this investigation is cross-sectional in nature, it is not clear if athletes are self-selected for higher bone mineral density and/or if it is the result of years of training in their respective sport.