Department of Surgery, Section of Plastic Surgery, Univ. of Michigan, BSRB, Rm. 2023, 109 Zina Pitcher Place, Ann Arbor, MI 48109-2200, USA.
J Appl Physiol (1985). 2011 Oct;111(4):1021-30. doi: 10.1152/japplphysiol.01119.2010. Epub 2011 Jul 28.
A two-arm, prospective, randomized, controlled trial study was conducted to investigate the effects of movement velocity during progressive resistance training (PRT) on the size and contractile properties of individual fibers from human vastus lateralis muscles. The effects of age and sex were examined by a design that included 63 subjects organized into four groups: young (20-30 yr) men and women, and older (65-80 yr) men and women. In each group, one-half of the subjects underwent a traditional PRT protocol that involved shortening contractions at low velocities against high loads, while the other half performed a modified PRT protocol that involved contractions at 3.5 times higher velocity against reduced loads. Muscles were sampled by needle biopsy before and after the 14-wk PRT program, and functional tests were performed on permeabilized individual fiber segments isolated from the biopsies. We tested the hypothesis that, compared with low-velocity PRT, high-velocity PRT results in a greater increase in the cross-sectional area, force, and power of type 2 fibers. Both types of PRT increased the cross-sectional area, force, and power of type 2 fibers by 8-12%, independent of the sex or age of the subject. Contrary to our hypothesis, the velocity at which the PRT was performed did not affect the fiber-level outcomes substantially. We conclude that, compared with low-velocity PRT, resistance training performed at velocities up to 3.5 times higher against reduced loads is equally effective for eliciting an adaptive response in type 2 fibers from human skeletal muscle.
一项双臂前瞻性随机对照试验研究旨在探讨渐进式抗阻训练（PRT）过程中运动速度对人体股外侧肌单个纤维大小和收缩性能的影响。该研究设计包括 63 名受试者，分为四组：年轻（20-30 岁）男性和女性，以及老年（65-80 岁）男性和女性，分别考察了年龄和性别对结果的影响。在每组中，一半受试者接受传统 PRT 方案，即进行低速度、高负荷的缩短收缩，而另一半则采用高速度、低负荷的改良 PRT 方案。在 14 周 PRT 方案前后，通过针吸活检取样肌肉，并对从活检中分离的单个纤维段进行功能测试。我们检验了一个假设，即与低速度 PRT 相比，高速度 PRT 会导致 2 型纤维的横截面积、力量和功率增加更大。两种 PRT 均使 2 型纤维的横截面积、力量和功率增加了 8-12%，与受试者的性别或年龄无关。与我们的假设相反，PRT 的速度并没有对纤维水平的结果产生实质性影响。我们得出结论，与低速度 PRT 相比，在降低负荷的情况下，速度高达 3.5 倍的阻力训练对于引起人体骨骼肌 2 型纤维的适应性反应同样有效。
