Ferrando A A, Tipton K D, Bamman M M, Wolfe R R
Shriners Burns Institute, Galveston 77550, Texas, USA.
J Appl Physiol (1985). 1997 Mar;82(3):807-10. doi: 10.1152/jappl.1997.82.3.807.
Spaceflight results in a loss of lean body mass and muscular strength. A ground-based model for microgravity, bed rest, results in a loss of lean body mass due to a decrease in muscle protein synthesis (MPS). Resistance training is suggested as a proposed countermeasure for spaceflight-induced atrophy because it is known to increase both MPS and skeletal muscle strength. We therefore hypothesized that scheduled resistance training throughout bed rest would ameliorate the decrease in MPS. Two groups of healthy volunteers were studied during 14 days of simulated microgravity. One group adhered to strict bed rest (BR; n = 5), whereas a second group engaged in leg resistance exercise every other day throughout bed rest (BREx; n = 6). MPS was determined directly by the incorporation of infused L-[ring-13C6] phenylalanine into vastus lateralis protein. After 14 days of bed rest, MPS in the BREx group did not change and was significantly greater than in the BR group. Thus moderate-resistance exercise can counteract the decrease in MPS during bed rest.
太空飞行会导致瘦体重和肌肉力量的丧失。一种模拟微重力的地面模型——卧床休息，会因肌肉蛋白质合成（MPS）减少而导致瘦体重下降。抗阻训练被认为是应对太空飞行引起的萎缩的一种对策，因为已知它能增加MPS和骨骼肌力量。因此，我们假设在整个卧床休息期间进行定期抗阻训练可以改善MPS的下降。两组健康志愿者在14天的模拟微重力环境下接受研究。一组严格卧床休息（BR组；n = 5），而另一组在整个卧床休息期间每隔一天进行腿部抗阻运动（BREx组；n = 6）。通过将注入的L-[环-13C6]苯丙氨酸掺入股外侧肌蛋白质中直接测定MPS。卧床休息14天后，BREx组的MPS没有变化，且显著高于BR组。因此，中等强度抗阻运动可以抵消卧床休息期间MPS的下降。
