阻力式訓練及鈣補充對骨質密度與骨骼代謝之影響

The effects of resistant training and calcium supplementation on bone mineral density and bone metabolism

目的：本研究探討四個月阻力式訓練及鈣補充對大學生骨質密度與骨骼代謝之影響。方法：健康的36名大學生分配至三組，分別為阻力式訓練組n=13（阻組）、阻力式訓練配合鈣補充組n=13（阻+鈣組），及控制組n=10（控制組）。阻力式訓練參照美國運動醫學會（ACSM）所建議的訓練處方，每週由二天漸增為三天（第二個月），每次二組（set）、10個動作包含身體的各大肌群，每一個動作做12-15次反覆，阻+鈣組除了阻力式訓練外並給予飯後鈣補充1000毫克／天，控制組需維持正常飲食及作息。訓練前及訓練後分別進行以下測驗：以雙能X光吸收儀（DEXA）來測量股骨頸（femoral neck）骨密度及腰椎第二至四節（L2-L4）密度；血液分析PTH、骨鈣素濃度為代謝指標。統計方法以混合設計二因子變異數分析考驗不同組別與訓練前、後測是否達顯著差異水準，顯著水準定為α=.05。結果：阻+鈣組可顯著增加股骨頸骨密度（p<.05），但對腰椎第二至第四節的骨密度並未達到顯著的差異水準（p>.05）。阻+鈣組可有效增加PTH和骨鈣素，達到顯著的差異水準（p<.05），但阻組卻沒有顯著的效果（p>.05）。結論：阻力式訓練配合鈣的補充可以增加血液中PTH值、骨鈣素及股骨頸骨密度，但在腰椎第二至第四節的骨密度並沒有顯著的改變，且單獨阻力式訓練未配合給予鈣的補充，無法增加受試者的PTH和骨鈣素，而骨密度的訓練效果也可能會受身體不同部位的影響，但仍需進一步的研究證實。

Purpose: The purpose of this study was to examine the effects of 4 months resistant training and calcium supplementation on bone mineral density and bone metabolism (parathyroid hormone, osteocalcin) in university students. Methods: Thirty-six students (age 21.3±0.9 yrs) were assigned to three groups. Resistant training group included 13 students (Group RT). Resistant training and calcium supplementation included 13 students (Group RTCS) and control group included 10 students (Group C). The subjects of Group RT and RTCS were asked to resistant training. The intensity was ACSM's recommended 12-15RM, 2-3 sets, 2-3 days per week during 4 months. The subjects of Group RTCS were given 1000mg calcium supplementation per day. Group C was asked to maintain their habitual lifestyle throughout the whole period of the study. All subjects underwent the following measurements: bone mineral density (BMD), parathyroid hormone, and osteocalcin were evaluated before and at the end of this study. BMD at L2-4 and femoral neck were measured with dual-energy X-ray absorptiometry (DEXA). The data were analyzed by two-way analysis of variance (Group×time) with repeated measures to examine any changes after training. The statistical significance was determined at α=0.05. Results: We found that femoral neck BMD was significant improvement between pre-training and post-training in Group RT and RTCS (p< .05). But there was no significant difference (p> .05) in lumbar spine(L2-4) BMD. We also found that PTH and osteocalcin was significant improvement in Group RTCS (p< .05) but not in Group RT and C. Conclusion: We suggest that resistance training and calcium supplementation (Group RTCS) can increase serum parathyroid hormone, osteocalcin and femoral neck BMD but not in lumbar spine BMD. Only resistant training (group RT) can't increase serum osteocalcin. Further studies are required to determine whether different regional BMD increases in resistant training and calcium supplementation for university students.