OSTEOGENIC EFFECT IN PRE-PUBERTAL ATHLETES PRACTICING DIFFERENT IMPACT-LOADING SPORTS

Introduction Physical activity involving weight bearing or jumping is beneficial per se to bone mineral accrual in children. However, there is large evidence that sports involving high impact loading (i.e., generated ground reaction forces greater than or equal to 3 times body weight) tend to produce a better overall osteogenic response than sports without impact loading (i.e., generated ground reaction forces = 0 times bodyweight). The aim of this study was to compare the effect of different impact loading sports on bone quality and body composition of pre-menarcheal athletes. Methods Thirty pre-menarcheal girls (aged 11.1±1.33[SD]y) participating in volleyball (VOLLEY, n=10) and artistic gymnastics at high (HGYM, n=10) and low (LGYM, n=10) intensity training underwent total body DXA analysis. Body composition (bone mineral content [BMC], fat-free soft tissue mass [FFST], fat mass [FM], and %FM) was assessed by dual-energy X-ray absorptiometry (DXA) at the total body and regional (arms, legs, trunk) level as well as specific axial skeleton sites (thoracic and lumbar spine, pelvis). Normality of data was assessed with the Kologorov-Smirnov test. Comparison of the three groups of pre-menarcheal athletes was performed with univariate ANOVA taking “group” as the within-subjects factor. Post-hoc analysis used Bonferroni’s correction for multiple comparisons. Statistical analysis was performed with SPSS v.16. Differences were considered significant when P≤0.05. Results After adjusting for body size, total body composition measurements were all significantly (p