Porter M M, Vandervoort A A
Faculty of Kinesiology, Elborn College, University of Western Ontario, London, Canada.
Eur J Appl Physiol Occup Physiol. 1997;76(1):62-8. doi: 10.1007/s004210050213.
Many studies have reported strength gains in older adults following high-intensity resistance training. However, the muscle contraction types examined have been primarily isometric (static) or concentric (CONC; shortening). Less is known about how eccentric (ECC) strength in older adults responds to training or about the efficacy of ECC contractions as training stimuli in these subjects, even though muscle contractions of this type are performed in most training regimens and daily physical activities. In this study, 15 physically active, healthy older women [68 (5) years; mean (SD)] completed an 8-week resistance training program of two sessions per week. Training consisted of three sets of eight repetitions of CONC ankle plantar flexion (PF) and ECC dorsiflexion (DF), at greater than 80% of the initial peak torque, in a standing position only. Subjects were tested in standing and supine positions for: (1) strength over a range of 10 degrees DF to 20 degrees PF for both CONC and ECC; DF and PF (2) passive resistive torque of the plantar flexors at 6 degrees/s; and (3) DF and PF rate of torque development. All strength testing and training was done at 30 degrees/s. Significant increases (P < 0.01) were found for both CONC DF (increases 30%) and ECC DF (increases 17%) peak torque in the standing position. No significant changes occurred for DF strength as measured with the subjects in the supine position, PF strength in either position, passive resistive torque, or rate of torque development. In summary, strength gains occurred only in the dorsiflexors, which were trained using ECC contractions. Improvements in DF strength were specific to the position of training, which has implications for the transferability of strength gains to functional tasks such as maintaining gait.
许多研究报告了老年人在进行高强度抗阻训练后力量有所增加。然而，所研究的肌肉收缩类型主要是等长（静态）或向心（CONC；缩短）收缩。对于老年人的离心（ECC）力量如何对训练做出反应，或者这种类型的肌肉收缩作为训练刺激因素在这些受试者中的效果，人们了解较少，尽管这种类型的肌肉收缩在大多数训练方案和日常体育活动中都会进行。在本研究中，15名身体活跃、健康的老年女性[68（5）岁；均值（标准差）]完成了一项为期8周的抗阻训练计划，每周进行两次训练。训练包括在站立位仅进行三组每组八次重复的向心踝关节跖屈（PF）和离心背屈（DF），强度大于初始峰值扭矩的80%。对受试者在站立位和仰卧位进行测试，内容包括：（1）在10度背屈至20度跖屈范围内向心和离心收缩时的力量；（2）跖屈肌在6度/秒时的被动阻力矩；（3）背屈和跖屈的扭矩发展速率。所有力量测试和训练均在30度/秒的速度下进行。结果发现，站立位时向心背屈（增加30%）和离心背屈（增加17%）的峰值扭矩均有显著增加（P<0.01）。仰卧位受试者的背屈力量、任何一个体位的跖屈力量、被动阻力矩或扭矩发展速率均无显著变化。总之，力量增加仅发生在通过离心收缩训练的背屈肌上。背屈力量的改善特定于训练体位，这对力量增加向诸如维持步态等功能任务的可转移性具有启示意义。
