Effects of a Ten-Second Maximum Voluntary Contraction on Regulatory Myosin Light-Chain Phosphorylation and Dynamic Performance Measures

• Autores: J. Chadwick Smith, Andrew C. Fry
• Localización: Journal of strength and conditioning research: the research journal of the NSCA, ISSN 1064-8011, Vol. 21, Nº. 1, 2007, págs. 73-76
• Idioma: inglés
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• Dialnet Métricas: 3 Citas
• Resumen

  • Smith, J.C., and A.C. Fry. Effects of a ten-second maximum voluntary contraction on regulatory myosin light-chain phosphorylation and dynamic performance measures. J. Strength Cond. Res. 21(1):73-76. 2007.-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.