Kryger A I, Andersen J L
Clinic of Occupational and Environmental Medicine, Bispebjerg University Hospital, Copenhagen, Denmark.
Scand J Med Sci Sports. 2007 Aug;17(4):422-30. doi: 10.1111/j.1600-0838.2006.00575.x. Epub 2007 May 9.
Resistance training-related changes in muscle strength, muscle size, fiber type, and myosin heavy chain isoform composition in 11 elderly subjects (age range, 85-97 years) after 12 weeks of heavy resistance training (80% of 1 RM) were examined. Twelve subjects constituted a control group. Resistance training increased isometric knee extensor strength 37% (P<0.05) and isokinetic knee strength 41-47% (P<0.05). Lean-quadriceps cross-sectional area increased 9.8% (P<0.05). Muscle fiber hypertrophy occurred only in the type 2 fibers (22% (P<0.05)). Type 1 fiber-type area percentage decreased [4.0 % (P<0.05)] whereas fiber-type area percentage of type 2a fibers increased [5.9% (P<0.05)]. The relative amount of myosin heavy chain (MHC) I (P<0.05) decreased and the relative amount of MHC IIA increased (P<0.05). No effects in the overall number of capillaries per area was observed, but an increase in the number of capillary contacts in the type 2 fiber pool was observed. Heavy resistance training does have beneficial effects on muscle strength and muscle volume in very old frail humans. Furthermore, an increase in fiber size of the fast muscle fibers and an overall increase in the relative amount of fast MHC IIA can lead not only to a stronger, but maybe more importantly, to a more powerful skeletal muscle.
对11名老年受试者（年龄范围85 - 97岁）进行12周大强度抗阻训练（1RM的80%）后，研究了与抗阻训练相关的肌肉力量、肌肉大小、纤维类型和肌球蛋白重链亚型组成的变化。12名受试者构成对照组。抗阻训练使等长膝关节伸肌力量增加37%（P<0.05），等速膝关节力量增加41 - 47%（P<0.05）。股四头肌瘦体重横截面积增加9.8%（P<0.05）。肌肉纤维肥大仅发生在2型纤维（22%，P<0.05）。1型纤维类型面积百分比下降[4.0%（P<0.05）]，而2a型纤维的纤维类型面积百分比增加[5.9%（P<0.05）]。肌球蛋白重链（MHC）I的相对含量下降（P<0.05），MHC IIA的相对含量增加（P<0.05）。未观察到每单位面积毛细血管总数的变化，但观察到2型纤维池内毛细血管接触数量增加。大强度抗阻训练对非常年老体弱的人的肌肉力量和肌肉体积确实有有益影响。此外，快肌纤维大小的增加以及快MHC IIA相对含量的总体增加不仅可导致更强壮的肌肉，而且可能更重要的是，可导致更有力的骨骼肌。
