PROTEIN, ENERGY AND EXERCISE EFFECTS ON SENESCENT MUSCLE

这些研究旨在研究膳食蛋白质的影响 对整个身体和部分蛋白质合成和 高强度渐进阻力时的骨骼肌质量 培训（PRT）计划。以前的研究表明， 男性和女性保持增加肌肉力量和 即使到了生命的第十个十年，我们 研究还表明，对运动的代谢反应， 特别是涉及偏心运动的运动， 老年人和年轻人之间的差异。与年轻人相比， 受试者经历更大量的肌肉损伤， 肌原纤维蛋白分解，减少嗜中性粒细胞和循环 肌酸激酶活性我们还证明， 运动增加了对膳食蛋白质和膳食补充剂的需求 将有利于老年男性肌肉质量的增长。这项研究导致 我们的假设，增加膳食蛋白质在高 强度PRT将增加肌肉蛋白质合成， 肥大率。老年男女将消耗一个合理的饮食 提供0.8或1.6g的蛋白质RDA三个月。因子 氮平衡沿着恒定的1- 13 C-亮氨酸灌注 将使我们能够检查全身氨基酸动力学， 将标记物掺入骨骼肌中以确定作用 饮食、年龄和PRT对肌肉蛋白质合成速率的影响。我们 已经表明，计算机断层扫描和活检分析是非常重要的， 敏感的工具来检查肌肉肥大的速度。这些 研究将是第一个在其中的影响，膳食蛋白质对 肌肉代谢，大小和力量将在一个紧密的检查， 控制代谢病房这项研究提供了一个机会， 检查老年人蛋白质RDA的充足性及其影响 N保持训练。这些研究将使我们能够 为老年人提供具体的营养建议， 继续进行力量训练

These studies are designed to study the influences of dietary protein on the whole body and fractional protein synthesis and the accretion of skeletal muscle mass during a high intensity progressive resistance training (PRT) program. Previous studies have demonstrated that older men and women retain the capacity to increase both muscle strength and size in response to PRT, even into the tenth decade of life. Our studies have also demonstrated that the metabolic response to exercise, particularly exercise that involves eccentric exercise, is quite different between old and young subjects. Compared to young, older subjects experience greater amounts of muscle damage, greater myofibillar protein breakdown, decreased neutrophilia and circulating creatine kinase activity. We have also demonstrated that regular exercise increases the need for dietary protein and a dietary supplement will favor the accretion of muscle mass in older men. This study leads us to the hypothesis that increased dietary protein during a high intensity PRT will increase muscle protein synthesisand increase the rate of hypertrophy. Older men and women will consume a eucaloric diet providing the protein RDA of 0.8 or 1.6g for three months. Factoral nitrogen balance along with constant, primed infusion of 1-13C-leucine will allow us to examine whole body amino acid kinetics and incorporation of the label into skeletal muscle to determine the effects of the diet, age, and PRT on the rate of muscle protein synthesis. We have shown that computerized tomography and biopsy analysis are very sensitive tools to examine the rate of muscle hypertrophy. These studies will be the first in which the effects of dietary protein on muscle metabolism, size and strength will be examined in a tightly controlled metabolic ward. This study provides an opportunity to examine the adequacy of the protein RDA in the elderly and the influence of training of N retention. These studies will allow us to make specific nutritional recommendations for the elderly as they initiate and continue with a strength training program.