Effect of sport training on forearm bone sites in female handball and soccer players

BACKGROUND: The objective of this study was to evaluate the bone mineral density (BMD) and Z-score of a skeletal region, considered as weight-bearing site in trained handball players (HP), but as non-weight-bearing site in trained soccer players (SP). The bone health status of the same site was also analyzed in an untrained group (CG). METHODS: BMD and Z-score at distal forearm regions (dominant, D; non-dominant, ND) were evaluated in 30 female HP and in 30 female SP, who have been training for 7.7 +/- 3.8 years, 17 hours per week, as well as in 30 females CG. RESULTS: Playing handball was associated with higher BMD of the skeleton at both measured sites than in CG. Also in comparison with SP, HPs' arms showed a significant increase in BMD. On the other hand, female SP have been reported to exhibit an enhanced ND arm BMD compared with controls. The benefits of exercise appeared to be significantly improved only in SP sub-group who started sport activity before or at menarche. These athletes showed at ND forearm a BMD 4% greater than those SP who started later, reaching a BMD of 11.6% higher than CG, a value similar to the corresponding in HP sub-group. Moreover, their D arm BMD was 7.1% higher compared with CG. CONCLUSIONS: This study indicates that, compared with non-trained subjects, long-term high-impact sport participation is associated with an higher bone health state, especially if the playing careers were started before or at menarche. This effect was observed at level of both forearms in HP, which are considered as weight-bearing sites for this discipline but also on the same skeletal regions of SP, which are not directly loaded by sport-related regular training.