Postactivation potentiation, fiber type, and twitch contraction time in human knee extensor muscles

• DOI: 10.1152/jappl.2000.88.6.2131
• Publication Date: 2017-12-23T00:37:01Z
• Authors: Taku Hamada; Digby G. Sale; J. Duncan MacDougall; Mark A. Tarnopolsky
• Keywords: Fast twitch muscle; Vastus lateralis muscle; Fiber type

In small mammals, muscles with shorter twitch contraction times and a predominance of fast-twitch, type II fibers exhibit greater posttetanic force potentiation than longer slow-twitch, I fibers. humans, the correlation between fiber-type distribution has not been found consistently. present study, postactivation (PAP) was induced in knee extensors 20 young men by 10-s maximum voluntary isometric (MVC). Maximal contractions were evoked before after MVC. A negative ( r = −0.73, P < 0.001) PAP pre-MVC time to peak torque (TPT). The four highest (HPAP, 104 ± 11%) lowest (LPAP, 43 7%) values 0.0001) underwent needle biopsies vastus lateralis. HPAP had percentage (72 9 vs. 39 7%, TPT (61 12 86 7 ms, 0.05) LPAP. These data indicate that, similar human higher PAP.