不同強度的耐力性游泳運動對大鼠骨骼發展的影響

The effects of different endurance swimming training intensities on bone development in rats

黃滄海(Tsang-Hai Huang)

指導教授 ： 謝伸裕 ； 楊榮森

國立臺灣師範大學/運動與休閒學院/體育學系/博士(2000年)

摘要

正常而良好的骨骼發展，機械性負荷是一個重要的因子，而負重式的運動較能讓骨骼獲得所需的機械性負荷。游泳運動的機械性負荷，主要來自於肌肉的牽張。本研究的目的旨在探討游泳強度不同是否會對骨骼系統產生不同強度的肌肉牽張，進而對骨骼發展有不同的影響。本研究以30隻Wistar雄性大鼠為樣本，以隨機分派的方式分成三組：SWIM 1組(高強度)，SWIM 2組(中強度)及控制組；運動訓練期間，逐週增加運動強度，SWIM 1組與SWIM 2組最終的強度分別為游泳時尾部懸掛4%及2%體重的重物，並於訓練結束後分析各項骨骼生長的變項。實驗結束時，兩組游泳運動組體重均顯著低於控制組（400.2±35.5, 394.8±32.1 < 473.1±31.6公克），伸趾長肌的檸檬酸合成酉每活性上則較控制組高（6.5±2.4, 6.5±1.5 > 4.9±1.3 mmole/g/min）。在血液分析方面，各項與骨代謝有關的指標（全鹼性磷酸酉每活性總量、第一型前膠原羧基端前胜月太及第一型膠原羧基端交鍵的末端胜月太）均無組間差異，但在骨骼代謝較旺盛的骨骨后區海綿骨則顯示，SWIM 1組（42±5%）及SWIM 2組（42±4%）的骨量比率顯著高於控制組（36±3%）。游泳運動組的大鼠在骨質密度（BMD）及脛骨或股骨部份區域的骨質含量（BMC）則較低於控制組，在骨骼外形上也顯著的較控制組較短且較細。骨骼材料力學的測驗亦顯示控制組脛骨及股骨的最大壓斷負荷（ML）及斷裂負荷（FL）均顯著高於游泳組，意指著控制組的骨骼強度較佳。然而在彎曲應力計算後，SWIM 2（208.6±24.8 Nt/mm2）的脛骨彎曲應力顯著高於控制組（150.2±27.0 Nt/mm2），而股骨的彎曲應力則沒有顯著差異。雖然有部份資料未達統計上的差異，仍可看出SWIM 1組的大鼠有較優於SWIM 2組的骨骼外形、骨密度及骨骼強度的趨勢。結論：（1）游泳運動造成較輕的體重，可能是造成BMD, BMC, 骨骼外形及材質等絕對值較差的原因；（2）耐力性的游泳運動對海綿骨骨量有促進作用，而且海綿骨骨量似有隨訓練強度增加的趨勢。

關鍵字

耐力運動 ； 游泳 ； 機械性負荷 ； 骨骼發展

並列摘要

Mechanical loading is an important factor for normal bone growth, and weight-bearing physical activities are necessary for the skeletal system to achieve sufficient mechanical loading. In swimming, the skeletal system receives its main mechanical loading from muscle contraction. It’s unknown whether different swimming intensities produce different muscle tension on the bone. The purpose of this study was to investigate the effects of different endurance swimming training intensities on skeletal development. Thirty male Wistar rats were randomly assigned into three groups: SWIM 1 group (high intensity), SWIM 2 group (moderate intensity) and a control group. The exercise intensity was increased weekly during the training period. At the end of the training period, animals of the SWIM 1 and SWIM 2 groups swam with a lead weight attached to the tail, which represented 4% and 2% of the animals’ body weight respectively. After 8 weeks of training, the swimming groups showed a significantly lower body weight than the control group (400.2±35.5, 394.8±32.1 <473.1±31.6g) and had higher citrate synthase activity in the extensor digitorum longus (EDL) (6.5±2.4, 6.5±1.5 > 4.9±1.3 mmole/g/min). There was no significant difference in serum bone markers, including total alkaline phosphatase (ALP), carboxyterminal propeptide of type I procollagen (PICP) and carboxyterminal cross-linked telopeptide of type I collagen (ICTP). However, the bone volume ratio of the epiphysis of the SWIM 1 (42±5%) and SWIM 2 (42±4%) groups was higher than the control group (36±3%)（p < .05）. The swim groups showed a significantly lower bone mineral density (BMD) and bone mineral content (BMC) in portions of the tibia and femur. For the bone shape, the swimming groups showed a shorter and more slender tibia and femur. Both swimming groups showed a weaker material property with a lower bending maximal load (ML) on the femur and a lower fracture load (FL) on the femur and tibia. However, the bending stress of the SWIM 2 group (208.6±24.8 Nt/mm2) showed a significantly better mechanical property on the tibia as compared to the control group (150.2±27.0 Nt/mm2). Although there was no significant difference, SWIM 1 showed higher values in bone shape parameters, BMD and material strength. Conclusions: 1) Swimming training causes lower body weight, and seems to negatively affect the absolute bone development (BMD, BMC, bone shape and bone mechanical properties); 2) A higher training intensity might lead to higher muscle tension which could contribute to better bone development.

並列關鍵字

endurance exercise ； swimming ； mechanical loading ； bone development

參考文獻

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