Differential effectiveness of low-intensity exercise in young and old rats.
Differential effectiveness of low-intensity exercise in young and old rats.
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低强度运动对年轻和年老大鼠的不同效果。
DOI：
10.1093/gerona/58.10.b889
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
Gabriel,Rob
中科院分区：
文献类型：
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作者：
Brown,Marybeth;Taylor,Jennifer;Gabriel,Rob
低强度运动增加了老年人的力量和功能，但尚不清楚这种变化是发生在“神经适应”之后，还是发生在内在肌肉适应之后。功能和力量是否会随之变化也不清楚。我们研究了中等强度、10次的运动计划对6月龄和30月龄大鼠肌肉质量、收缩力量和功能(步态)的影响。动物每周进行5天45分钟的活动(例如，坡道行走、平衡)。在老年动物中，比目鱼肌、足底肌、指长伸肌和腓骨长肌的肌肉质量和峰值收缩力与对照组相比显著增加，但没有恢复到年轻对照组的水平。老年大鼠的肌力增加伴随着步幅的显著延长(90±9至103±15 mm)，但仍比青年大鼠的步幅小23%。年轻大鼠的肌肉功能和步态随运动的变化不明显。结果表明：(A)在适度的活动计划下，老年机体的肌肉质量和力量可以发生快速而显著的变化，(B)年轻大鼠和老年大鼠的肌肉适应阈值可能不同，(C)老年大鼠的力量和功能变化可能是同时发生的。
Low-intensity exercise increases strength and function in old adults, but it is unclear if change occurs secondary to “neural adaptation” or to intrinsic muscle adaptation. Whether function and strength change concomitantly is also unclear. We examined effects of a modest intensity, 10-session exercise program on muscle mass, contractile force, and function (gait) in 6-month-old and 30-month-old rats. Animals underwent 45 minutes of activity (e.g., ramp walking, balancing) 5 days/week. In old animals, a significant increase in muscle mass and peak contractile force occurred with exercise in soleus, plantaris, extensor digitorum longus, and peroneus longus compared with controls, but did not restore values to those for young controls. The increase in muscle force in old rats was accompanied by a significant lengthening of stride (90 ± 9 to 103 ± 15 mm), which was still 23% less than stride values for young rats. Changes in muscle function and gait with exercise were not apparent in young rats. Results suggest that (a) rapid and significant changes in muscle mass and strength in an aged organism can occur with a modest activity program, (b) the threshold for muscle adaptation may differ in young versus old rats, and (c) changes in strength and function in old rats may occur concomitantly.