The Relationship Between Muscular Strength, Jump Power, and Bone Health in Collegiate Distance Runners

Participation in sports, especially those involving impact loading, enhance bone mineral content (BMC) and density (BMD). Additionally, participation in impact loading sports may strengthen relationships between strength or power and bone variables. The purpose of this investigation was to examine relationships between measures of muscular performance and bone variables in Division I endurance athletes (29 males, 31 females, 19.6 ± 1.4 years). Dual-energy x-ray absorptiometry (DXA) scans were analyzed at the anterior-posterior (AP) and lateral (LAT) spine, femoral neck (FN), total hip (TH), whole body (WB), and ultra-distal forearm (UD) for BMC and BMD measures. WB scans provided information for bone-free lean mass (BFLM). Performance measures included absolute, and relative (to body weight), grip strength (GS) and absolute lower body power (LBP) derived from a vertical jump. Pearson correlation coefficients were determined between bone variables and muscular performance measures. Hierarchical multiple regression was used to quantify the variance explained in bone variables. Male runners showed strong relationships between absolute and relative GS and numerous bone variables. Female runner had significant relationships between absolute jump power and numerous bone variables. Sex, GS, and LBP explained 41-76% of BMC at the various bone sites and 12-30% of BMD. Results indicate that in collegiate men, greater strength is related to higher BMC and BMD, however this was not the case for women. In female collegiate distance runners, higher jump power was related to greater BMC and BMD.