Open AccessEFFECTS OF A TEN-SECOND MAXIMUM VOLUNTARY CONTRACTION ON REGULATORY MYOSIN LIGHT-CHAIN PHOSPHORYLATION AND DYNAMIC PERFORMANCE MEASURES
Author(s) -
J. W. G. Smith,
Andrew C. Fry
Publication year - 2007
Publication title -
journal of strength and conditioning research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.569
H-Index - 128
eISSN - 1533-4287
pISSN - 1064-8011
DOI - 10.1519/00124278-200702000-00014
Subject(s) - phosphorylation , long term potentiation , myosin , myosin light chain kinase , contraction (grammar) , turnover , psychology , physical medicine and rehabilitation , medicine , chemistry , biochemistry , economics , receptor , management
The purpose of this investigation was to evaluate the role of an elevated regulatory myosin light-chain (RLC) phosphorylation on subsequent postactivation potentiation induced by a 10-second maximum voluntary contraction (MVC). With the use of a repeated measures design, data were collected from 11 recreationally active men who performed an explosive knee extension exercise with a load of 70% of their 1 repetition maximum. Muscle biopsies of their vastus lateralis were taken pre- and post-MVC. Seven subjects had elevated RLC phosphorylation (positive responders) and 4 had a decrease in RLC phosphorylation (negative responders). Percent change of force, velocity, and power measures did not differ between the 2 groups. Our results suggest that recreationally active men will not benefit from the effects of postactivation potentiation during performance with a 7-minute recovery period. Furthermore, we suggest that training status, strength, and skill level might be key determining factors for the positive benefits of postactivation potentiation during performance.