Muscle-to-Bone Ratio in Collegiate Female Athletes in Low and High Impact Sports

The purpose of the present study was to compare the muscle-to-bone ratio in National Collegiate Athletic Association Division I female athletes (n=387) to those in age-matched controls (n=209). In addition, we examined the muscle-to-bone ratio in low and high impact sports. Total and regional lean soft tissue, fat mass, and bone mineral content were determined by dual X-ray absorptiometry. The muscle-to-bone ratio was calculated by dividing lean soft tissue by bone mineral content. Athletes were categorized by sports: basketball (n=66), cross-country (n=49), diving (n=17), soccer (n=69), softball (n=71), swimming (n=93), and volleyball (n=22). There were significant differences between controls and athletes for total lean soft tissue, fat mass, and bone mineral content. When the total muscle-to-bone ratio in athletes was compared to that in controls, there were no significant differences; however, there were significant differences in the regional muscle-to-bone ratio. Low impact sports (i.e., diving and swimming) had significantly higher total and regional muscle-to-bone ratios than high impact sports (i.e., cross-country, basketball, volleyball, softball, and soccer). The differences identified between sports in total and regional muscle-to-bone ratios may be a result of sport-specific impact and mechanical strain affecting the balance between the muscle and the bone. This study provides insights into how training-induced body composition impacts the balance between the tissues in female athletes.