title: Effect of postactivation potentiation on the maximal voluntary isokinetic concentric torque in humans.
abstract: The purpose of this study was to examine whether postactivation potentiation (PAP) influences dynamic torque development in humans. Nine recreationally active men performed sets of 3 maximal isokinetic concentric plantar flexions at 180 degrees/second in the following sequence: before and immediately (5 seconds) after a 10-second maximal voluntary contraction (MVC) and then every 1 minute until the 5-minute point, followed by 1 more stimulation at the 10-minute point. Twitch responses were recorded before every set of 3 concentric contractions to examine whether the PAP exists. The twitch and concentric torques were potentiated at 0 through 5 minutes and 1 through 3 minutes post-MVC, respectively (p < 0.05), whereas there was no significant difference in concentric torque in the control (without MVC) condition (p > 0.05). For electromyographic signals during concentric contractions, muscle activity of the medial gastrocnemius was significantly depressed only immediately after the conditioning MVC (p < 0.05). These results indicate that a brief maximal voluntary isometric contraction enhances voluntary dynamic performance through PAP, within proper recovery interval. From a practical point of view, in sports activities we suggest undertaking PAP through high-intensity contractions 1 to 3 minutes before voluntary ballistic or plyometric actions for improved performance.
authors.affiliation: Faculty of Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan. miyamoto@aoni.waseda.jp
authors.forename: Naokazu
authors.initials: N
authors.lastname: Miyamoto
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kanehisa
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Fukunaga
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Kawakami
mesh_terms: D000328:Adult; D056352:Athletes; D054874:Athletic Performance / Q000502:physiology; D004558:Electric Stimulation / Q000379:methods; D004576:Electromyography; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D055070:Resistance Training; D019415:Torque; D055815:Young Adult