Bone Mineral Content Distribution in Response to Long-term Training of Elite Rowers.

Abstract

Bone response to exercise depends on the type and size of the mechanical stimulus. In rowing, athletes are exposed to low mechanical but large compression loads mainly on the trunk. Thus, this study aimed to investigate the impact of rowing on total and regional bone quality and bone turnover parameters in elite rowing athletes vs. control subjects. Twenty world-class rowers and twenty active, but not athletic, men participated in the study. Bone mineral density (BMD) and body mineral content (BMC) were assessed by dual-energy X-ray absorptiometry (DXA). Bone turnover markers (OPG and RANKL) in serum were assessed by Elisa method. The current research revealed no statistical difference in total bone mineral density (TBMD) and total body mineral content (TBMC) between elite-level rowers and control subjects. Nevertheless, Trunk BMC (p=0.02) and Trunk BMC/TBMC ratio (p=0.01) were significantly higher in rowers than those in the control group. In contrast, in the control group, the Lower limbs BMC/TBMC ratio (p=0.007) was statistically higher. Furthermore, RANKL (p=0.011) and OPG (p=0.03) were statistically significantly higher in rowers, whereas the OPG/RANKL ratio (p=0.012) was statistically higher in the control group. Rowing, as a non-weight-bearing exercise, did not alter total bone density but induced a remarkable redistribution of bone density from the lower limbs to the trunk. In addition, the current evidence suggests that the underlying molecular mechanism is based on turnover of intermediates, rather than solely bone redistribution.