Postactivation Potentiation Biases Maximal Isometric Strength Assessment

[摘要] Postactivation potentiation (PAP) is known to enhance force production. Maximal isometric strength assessment protocols usually consist of two or more maximal voluntary isometric contractions (MVCs). The objective of this study was to determine if PAP would influence isometric strength assessment. Healthy male volunteers (n=23) performed two five-second MVCs separated by a 180-seconds interval. Changes in isometric peak torque (IPT), time to achieve it (tPTI), contractile impulse (CI), root mean square of the electromyographic signal during PTI (RMS), and rate of torque development (RTD), in different intervals, were measured. Significant increases in IPT (240.6 ± 55.7 N·mversus248.9 ± 55.1 N·m), RTD (746 ± 152 N·m·s−1versus727 ± 158 N·m·s−1), and RMS (59.1 ± 12.2%RMSMAX  versus54.8 ± 9.4%RMSMAX) were found on the second MVC. tPTI decreased significantly on the second MVC (2373 ± 1200 msversus2784 ± 1226 ms). We conclude that a first MVC leads to PAP that elicits significant enhancements in strength-related variables of a second MVC performed 180 seconds later. If disconsidered, this phenomenon might bias maximal isometric strength assessment, overestimating some of these variables.

[学科分类] 基础医学