Theoretical Background and Practical Applications of the Physiological Mechanism of Post-Activation Potentiation

Abstract

Post-activation potentiation (PAP) is a mechanism that has gained interest in research during the past years. This is due to the fact that several studies use this physiological mechanism as a tool to improve athletic performance. This review will describe the basic principles of PAP and how exercise can influence the existence and magnitude of PAP. As definition, PAP is the phenomenon of increased force or twitch output that occurs after a high-intensity voluntary or evoked contraction. Although PAP is assumed to occur within the muscle due to the increased phosphorylation of the myosin light chains, several other factors can influence its appearance. The fact that fatigue counteracts the level of PAP, muscular as well as neural properties of the neuromuscular system contribute to the final outcome, despite the fact that PAP is mainly a mechanism that is attributed to changes in muscular level. During the past 5 years, our research group has examined in depth central and peripheral mechanisms that influence performance under the co-existence of PAP and fatigue. Numerous techniques combining the application of electromyography, electrical stimulation and force recording are briefly presented and discussed with emphasis on the practical aspect of interpretation on athletic performance. Using such techniques, some of the recent findings of our research group are presented, giving an insight in the PAP effect immediately after a contraction or after series of contractions and the effectiveness of long-term combined training programs.