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

The purpose of this study was to compare muscle-to-bone ratio (MBR) in NCAA Division I male athletes (n=638) to healthy, age-matched controls (n=260). In addition, we compared MBR in low and high impact sports. Measures of total and regional lean mass (LM), fat mass (FM), and bone mineral content (BMC) were made using dual X-ray absorptiometry (DXA). MBR was calculated by dividing LM by BMC. Athletes were categorized by sport: basketball (n=51), baseball (n=80), football (n=348), ice hockey (n=47), swimming (n=25), tennis (n=29), and cross country (n=58). It was expected that total MBR would be greater in athletes than controls. In addition, it was expected that low impact sports (i.e., swimming) would have a higher total and regional MBR than high impact sports (i.e., football, basketball, etc.). Athletes were significantly (p≤0.01) taller (185±7.8 vs.175 ±6.6 cm ) and weighed significantly (p≤0.01) more (95.8±20.5 vs 74 .9±1.91 kg) than the controls. There were significantly (p≤0.01) higher FM (17.7±10.1 vs 15.2±7.1 kg), LM (74 .0±11.4 vs. 56.9±7.7 kg), BMC (4 .0±0.6 vs. 3.1±0.5 kg), in the athletes compared to controls. The athletes also had a significantly (p≤0.01) greater overall MBR (18.5±1.4 vs. 18.8±1.7) than controls. The total MBR was greater (p≤0.01) in low impact sports such as swimming (20.2±2) than athletes from higher impact sports such as baseball (18.4±1.3), basketball (18 .0±1.4), football (18.6±1.3), ice hockey (18 .0±1.6), tennis (17.6±1.1), and cross country (18.5±1.4). Additionally, football players had a significantly (p=0.01) higher total MBR than tennis players. Regional MBR also demonstrated significant differences between low and high impact sports with leg MBR being greater (p≤0.01) in swimmers (18.3±2) than baseball (16.4±1.8), basketball (15.9±2), football (16.7±1.5), ice hockey (16.1±1.9), tennis (15.4±1.1), and cross country (15.1±1.2) athletes. Swimmers also had greater (p≤0.01) arm MBR (17.8±1.9) than baseball (16.3±1.4), ice hockey (16.2±1.3), tennis (16.2±1 .0), and cross country (15.9±1.5). Football players had significantly greater arm MBR (17.3±1.4) than a baseball, ice hockey, tennis, and cross country. Cross country runners had a lower arm MBR than football and baseball athletes. The difference in FM, LM, BMC, and MBR between the athletes and controls could be explained by the higher intensity training levels exhibited by NCAA athletes. The differences found in total and regional MBR between swimming, a low impact sport, and higher impact sports may be a result of sport-specific impact and mechanical strain affecting the balance between muscle and bone. Learning more about sport-specific body composition may inform injury prevention and performance improvement strategies. This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.