LUMBAR SPINE, FEMORAL NECK AND WHOLE BODY BONE MASS CHANGES IN FEMALE COLLEGIATE ATHLETES 28

Abstract

The purpose of this study was to determine bone mineral density (BMD) changes in the lumbar spine (LS), femoral neck (FN) and whole body (WB), including arm and leg regions, over one year in competitive female athletes(mean age: 19.8 ± 1.9 yr). Subjects were 15 track (T) athletes. 15 soccer (S) players, 8 volleyball (VB) players and 10 non-athletic control (C) women. Years of specific sport training averaged 6.8±3.4 yr, 11.7±4.6 hr/wk. Additional supplemental training averaged 5.1±3.2 hr/wk. Weight and BMI did not differ among groups; VB were significantly taller than all others. BMD was assessed using dual-energy x-ray absorptiometry (DXA); baseline and post-test measures were separated by 11.3±1.4 months. Age of menarche was not different among groups, and the incidence of oligo- and amenorrhea was low: 3T, 2S and 1C. Menstrual cycle status did not affect% change in BMD at any site. The% change in BMD at the FN, WB and arm sites was not significantly different among groups (p>0.05). Only the soccer players'% change in WB BMD was different from zero(0.7±1.2%). Significant group differences were found for% change in LS(p<0.05) and leg BMD (p<0.01): Table The% change in LS BMD (all subjects) was significantly related to nutritional intake (p<0.05): total calories (R2=0.16), calcium(R2=0.24), and Vitamin D (R2=0.12). In conclusion, soccer and track athletes exhibited the most significant (positive) changes in BMD over one year, possibly due to: 1) relatively more specific (T) and supplemental(S) training hours/week compared to volleyball, and/or 2) higher caloric and calcium intake, necessary for building bone mass.