Aagaard Per, Magnusson Peter S, Larsson Benny, Kjaer Michael, Krustrup Peter
Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
Med Sci Sports Exerc. 2007 Nov;39(11):1989-96. doi: 10.1249/mss.0b013e31814fb402.
Maximal muscle contraction force and muscle mass are both reduced during the natural aging process. Long-term training may be used to attenuate this age-related loss in muscle function and muscle size.
Maximum isometric quadriceps strength (MVC), rate of force development (RFD), and muscle fiber composition and size (CSA) were studied in elderly individuals (68-78 yr) chronically exposed (> 50 yr) to either endurance (E) or strength (S) training, and in age-matched, untrained (U) elderly group.
E and S showed greater MVC than did U. Contractile RFD was elevated in S compared with U, and S also demonstrated greater type II fiber CSA than did U and E. The proportion of type I fibers was greater in E compared with U and S.
Muscle fiber size and mechanical muscle performance, particularly RFD, were consistently elevated in aged individuals exposed to chronic (i.e., lifelong) strength training. This relative preservation in muscle morphology and function may provide an important physical reserve capacity to retain muscle mass and function above the critical threshold for independent living at old age.
在自然衰老过程中，最大肌肉收缩力和肌肉质量均会下降。长期训练可用于减轻与年龄相关的肌肉功能和肌肉大小的损失。
对长期（>50年）进行耐力（E）或力量（S）训练的老年人（68 - 78岁）以及年龄匹配的未经训练（U）的老年组进行最大等长股四头肌力量（MVC）、力量发展速率（RFD）和肌肉纤维组成及大小（CSA）的研究。
E组和S组的MVC均高于U组。与U组相比，S组的收缩性RFD升高，且S组的II型纤维CSA也大于U组和E组。与U组和S组相比，E组的I型纤维比例更高。
长期（即终身）进行力量训练的老年人，其肌肉纤维大小和肌肉机械性能，尤其是RFD，持续升高。这种肌肉形态和功能的相对保留可能为维持肌肉质量和功能提供重要的身体储备能力，使其高于老年独立生活的临界阈值。
