Candow Darren G, Chilibeck Philip D, Facci Marina, Abeysekara Saman, Zello Gordon A
School of Human Kinetics, Laurentian University, Sudbury, ON, Canada.
Eur J Appl Physiol. 2006 Jul;97(5):548-56. doi: 10.1007/s00421-006-0223-8. Epub 2006 Jun 10.
We determined the effects of protein supplementation immediately before (PRO-B) and after (PRO-A) resistance training (RT; 12 weeks) in older men (59-76 years), and whether this reduces deficits in muscle mass and strength compared to younger men (18-40 years). Older men were randomized to PRO-B (0.3 g/kg protein before RT + placebo after RT, n=9), PRO-A (placebo before + protein after RT, n=10), or PLA (placebo before and after RT, n=10). Lean tissue mass, muscle thickness of the elbow, knee, and ankle flexors and extensors, and leg and bench press strength were measured before and after RT and compared to databases of younger subjects (n=22-60). Myofibrillar protein degradation (3-methylhistidine) and bone resorption (cross-linked N-telopeptides) were also measured before and after RT. Lean tissue mass, muscle thickness (except ankle dorsi flexors), and strength increased with training (P<0.05), with little difference between groups. There were no changes in 3-methylhistidine or cross-linked N-telopeptides. Before RT, all measures were lower in the older compared to younger groups (P<0.05), except for elbow extensor muscle thickness. Following training, muscle thickness of the elbow flexors and ankle dorsi flexors and leg press strength were no longer different than the young, and elbow extensor muscle thickness was greater in the old men (P<0.05). Supplementation with protein before or after training has no effect on muscle mass and strength in older men. RT was sufficient to overcome deficits in muscle size of the elbow flexors and ankle dorsi flexors and leg press strength in older compared to younger men.
我们确定了在老年男性（59 - 76岁）进行抗阻训练（RT；12周）之前（PRO - B）和之后（PRO - A）补充蛋白质的效果，以及与年轻男性（18 - 40岁）相比，这是否能减少肌肉质量和力量的不足。老年男性被随机分为PRO - B组（RT前补充0.3 g/kg蛋白质 + RT后补充安慰剂，n = 9）、PRO - A组（RT前补充安慰剂 + RT后补充蛋白质，n = 10）或PLA组（RT前后均补充安慰剂，n = 10）。在RT前后测量瘦体重、肘部、膝部和踝部屈肌与伸肌的肌肉厚度以及腿部和卧推力量，并与年轻受试者（n = 22 - 60）的数据库进行比较。还在RT前后测量了肌原纤维蛋白降解（3 - 甲基组氨酸）和骨吸收（交联N - 端肽）。瘦体重、肌肉厚度（踝背屈肌除外）和力量随训练增加（P < 0.05），组间差异不大。3 - 甲基组氨酸或交联N - 端肽没有变化。在RT前，除肘部伸肌肌肉厚度外，老年组的所有测量值均低于年轻组（P < 0.05）。训练后，肘部屈肌和踝背屈肌的肌肉厚度以及腿部推举力量与年轻人不再有差异，老年男性的肘部伸肌肌肉厚度更大（P < 0.05）。训练前或后补充蛋白质对老年男性的肌肉质量和力量没有影响。与年轻男性相比，RT足以克服老年男性肘部屈肌、踝背屈肌的肌肉大小以及腿部推举力量的不足。
