Investigation of Post-activation Potentiation Phenomenon οn Sprinting Performance Following Power Pre-conditioning Exercise

Sprinting ability is an imperative quality for many sports, especially for sprint and power athletes. Regular sprint training improves acceleration, maximal speed and power. Thus, sprint training consists one of the basic elements of the athletes' training program.

One method used by coaches to improve performance is the implementation of a pre-conditioning exercise aiming to post-activation potentiation (PAP). Post-activation potentiation phenomenon refers to the increase in performance following a maximal or near maximal muscle contraction (e.g. a pre-conditioning exercise). However, the effectiveness of such an approach is under debate, such that improvement, but also no improvement, or even deterioration of the performance following pre-conditioning exercises has been reported. The improvement of performance following a pre-conditioning exercise seems to depend on the relationship between muscle twitch potentiation and fatigue following the pre-conditioning exercise. When muscle twitch potentiation is greater than muscle fatigue, then the PAP mechanism will be activated and performance will be improved. Contrary, under similar muscle twitch potentiation and fatigue, performance will not change, and when muscle twitch potentiation is lower than fatigue, muscle performance will decrease. PAP phenomenon has been studied mainly regarding its effectiveness to improve jumping performance, while its effectiveness on improving sprinting performance has not been adequately studied. However, information regarding the effectiveness of the implementation of pre-conditioning exercises aiming to improve sprinting performance, is important for the design of an optimum training program for the maximization of the athletes' performance and the avoidance of injuries.

The aim of this study is to investigate a) the effectiveness of the implementation of a pre-conditioning exercise to activate the PAP mechanism and improve performance of a following sprint, and b) to investigate whether PAP is maintained in repeated efforts during the same training session.

The study will be implemented in a randomized, cross over, repeated measures design, at three cycles.

According to a preliminary power analysis (a probability error of 0.05, and a statistical power of 80%), a sample size of 8 - 10 participants was considered appropriate in order to detect statistically meaningful differences between groups. Considering a possible drop-out, 15 participants will be recruited. Procedures will be in accordance with the 1964 Declaration of Helsinki, as revised in 2013.