Greater Total And Regional Bone Mineral Density In Adult Male Long-distance Runners Who Resistance Train

Abstract

Numerous studies report low bone mineral density (BMD) in male long distance runners. In contrast, resistance training can increase BMD; however, the efficacy of combining resistance training with long distance running has not been elucidated. PURPOSE: The purpose of this study was to investigate the relation of engaging in resistance training and BMD in long-distance runners. METHODS: Participants consisted of 25 apparently healthy Caucasian men (mean ± SD; 25.9 ± 2.9 y; 1.77 ± 0.04 m, 75.4 ± 8.5 kg) who reported belonging to one of the following three groups based on exercise engagement over the previous three years: Non-exercise trained control (CON; n=8) participated in less than 1 hour of exercise per week; Non-resistance trained runners (NRT; n=8) ran at least 20 miles per week and did not engage in resistance training; and Resistance trained runners (RT; n=9) ran at least 20 miles per week and engaged in at least one resistance training session per week. NRT and RT did not participate in any aerobic cross training (biking, swimming, etc.) over the previous three years. Participants completed medical and exercise training history questionnaires. Body composition including BMD (total body, femoral neck region, femoral greater trochanteric region, femoral total region, and L1-L4 lumber spine) was assessed using dual energy X-ray absorptiometry (DXA). RESULTS: Age, height, and total mass did not differ between groups. RT and NRT had greater lean body mass and less body fat % than CON (p < 0.05). At all measured sites, BMD was greater for RT (total body: 1.37 ± 0.09 g·cm-2; total femur region: 1.27 ± 0.15 g·cm-2; lumbar spine: 1.37 ± 0.12 g·cm-2) compared to NRT (total body: 1.28 ± 0.10 g·cm-2; total femur region: 1.08 ± 0.14 g·cm-2; lumbar spine 1.19 ± 0.09 g·cm-2) and CON (total body: 1.21 ± 0.07 g·cm-2; total femur region: 1.01 ± 0.10 g·cm-2; lumbar spine 1.22 ± 0.12 g·cm-2). NRT and CON did not differ in BMD at any measured site. CONCLUSION: Young adult male long-distance runners who engage in resistance training had greater BMD than non-resistance trained runners and non-exercise trained peers. Despite the weight bearing and repeated impact nature of running, BMD did not differ between NRT and CON at any measured site. Although causation cannot be determined with the present study design, the findings suggest that runners should perform resistance exercise at least once per week since this is associated with greater BMD.