Sport-specific association between exercise loading and the density, geometry, and microstructure of weight-bearing bone in young adult men

Abstract

In this population-based study of 24-year-old men, we have investigated the association between sport-specific exercise loading and different bone parameters. We reveal that the association between exercise loading and bone parameters is sport-specific, indicating that nonspecific resistance exercise does not impact bone density, geometry, or microstructure in young men.

Introduction: In this cross-sectional study, the association between nonspecific resistive exercise and areal and volumetric bone density, bone geometry, or bone microstructure was investigated in young adult men.

Methods: A total of 184 male athletes, 24.0 ± 0.6 years of age (mean ± SD), representing nonspecific resistive exercise and soccer (proportion of recreational athletes, 93.4 and 7.7 %, respectively), and 177 nonathletic age-matched controls were measured with dual-energy X-ray absorptiometry. Radius and tibia were measured by peripheral quantitative computed tomography (pQCT) at the diaphysis and by three-dimensional pQCT at the metaphysis.

Results: Men in the nonspecific resistive exercise group had higher grip strength(9.1 % or 0.4 SD) and higher lean mass(5.6 % or 0.5 SD) than those in the nonathletic group(p < 0.01 and p < 0.001, respectively). However, men who participated in nonspecific resistive exercise did not have higher bone density or a more favorable bone microstructure or geometry than their nonathletic referents. In contrast, men playing soccer had higher areal bone mineral density (aBMD) at the femoral neck (19.5 % or 1.2 SD) and lumbar spine (12.6 % or 1.0 SD), as well as larger cortical cross-sectional area (16.4 % or 1.1 SD) and higher trabecular bone volume fraction (14.5 % or 0.9 SD), as a result of increased trabecular number (8.7 % or 0.6 SD) and thickness (5.7 % or 0.4 SD) at the tibia than men in the nonathletic group(p < 0.001).

Conclusions: Weight-bearing exercise with impacts from varying directions (playing soccer) is associated with aBMD and volumetric BMD, cortical bone geometry, as well as trabecular microstructure of weight-bearing bone. Nonspecific recreational resistance exercise does not appear to be a strong determinant of bone density, geometry, or microstructure in young adult men.

Fig. 1

a, b Sport-specific association between exercise loading and grip strength or lean mass. One-way ANOVA followed by Tukey’s post hoc test was used for evaluating differences between the nonathletic, resistance training, and soccer-playing groups of young adult men. Values are given as mean difference (SD ± 95 % CI) compared to the mean of the nonathletic group, represented by the 0 line

Fig. 2

a, b Sport-specific association between exercise loading and aBMD. One-way ANOVA followed by Tukey’s post hoc test was used for evaluating differences between the nonathletic, resistance training, and soccer-playing groups of young adult men. Values are given as mean difference (SD ± 95 % CI) compared to the mean of the nonathletic group, represented by the 0 line

Fig. 3

a–d Sport-specific association between exercise loading and volumetric density, geometry, or microstructure in weight-bearing bone. One-way ANOVA followed by Tukey’s post hoc test was used for evaluating differences between the nonathletic, resistance training, and soccer-playing groups of young adult men. Values are given as mean difference (SD ± 95 % CI) compared to the mean of the nonathletic group, represented by the 0 line