Yarasheski K E, Pak-Loduca J, Hasten D L, Obert K A, Brown M B, Sinacore D R
Claude D. Pepper Older American's Independence Center, Divisions of Geriatrics and Gerontology and Metabolism, Endocrinology, and Diabetes, Washington University Medical Center, St. Louis, Missouri 63110, USA.
Am J Physiol. 1999 Jul;277(1):E118-25. doi: 10.1152/ajpendo.1999.277.1.E118.
Muscle atrophy (sarcopenia) in the elderly is associated with a reduced rate of muscle protein synthesis. The purpose of this study was to determine if weight-lifting exercise increases the rate of muscle protein synthesis in physically frail 76- to 92-yr-old women and men. Eight women and 4 men with mild to moderate physical frailty were enrolled in a 3-mo physical therapy program that was followed by 3 mo of supervised weight-lifting exercise. Supervised weight-lifting exercise was performed 3 days/wk at 65-100% of initial 1-repetition maximum on five upper and three lower body exercises. Compared with before resistance training, the in vivo incorporation rate of [(13)C]leucine into vastus lateralis muscle protein was increased after resistance training in women and men (P < 0.01), although it was unchanged in five 82 +/- 2-yr-old control subjects studied two times in 3 mo. Maximum voluntary knee extensor muscle torque production increased in the supervised resistance exercise group. These findings suggest that muscle contractile protein synthetic pathways in physically frail 76- to 92-yr-old women and men respond and adapt to the increased contractile activity associated with progressive resistance exercise training.
老年人的肌肉萎缩（肌肉减少症）与肌肉蛋白合成速率降低有关。本研究的目的是确定举重锻炼是否能提高身体虚弱的76至92岁男女的肌肉蛋白合成速率。8名女性和4名男性，身体有轻度至中度虚弱，参加了一个为期3个月的物理治疗项目，随后是3个月的有监督的举重锻炼。有监督的举重锻炼每周进行3天，针对五项上肢和三项下肢运动，强度为初始1次最大重复量的65%-100%。与抗阻训练前相比，无论男女，抗阻训练后[（13）C]亮氨酸在股外侧肌蛋白中的体内掺入率均增加（P<0.01），不过在3个月内接受两次研究的5名82±2岁的对照受试者中，该掺入率没有变化。在有监督的抗阻运动组中，最大自主伸膝肌扭矩产生增加。这些发现表明，身体虚弱的76至92岁男女的肌肉收缩蛋白合成途径对与渐进性抗阻运动训练相关的收缩活动增加有反应并能适应。
