Two days ago we wrote about the amazing post-activation-potentiation [PAP] effect, which causes athletes' muscles to generate more power after a short maximal exertion. We wanted to know more, so we went looking. And we found a study in the Journal of Strength and Conditioning Research, in which researchers at Imperial College London boosted rugby players' ability to jump by making use of the PAP effect.
The researchers did experiments on 9 rugby players who were able of lifting at least one and a half times their bodyweight with squats. After an extensive warm-up, the players then did one set of squats using a weight with which they could just manage 3 reps. After that they rested, for a period varying from 15 seconds to 16 minutes.
After resting the players either had to do horizontal sled pushes, do 5 and 10 m sprints or do jumps. Only when the players did the latter – the countermovement jump – did the researchers record effects that were statistically significant. The players jumped higher in the period 4-12 minutes after the squats session.
The researchers also stress that each player took a different amount of time to recover after the squats session. So strength athletes who want to use the PAP effect to boost their performance would probably do best to experiment themselves to find out what their optimal recovery time is.
Not all of the rugby players experienced the PAP effect. Two players, even after optimal recovery times, didn't perform any better after the squat session, and one even jumped less high.
The researchers also measured the players' blood testosterone concentration to see whether this might explain the PAP effect. But the results were inconclusive.
"The sport-specific outcomes should determine the selection of the PAP stimuli to ensure similar movement patterns with the test exercises", the researchers conclude. "Some possible examples include the use of vertical back squats to potentiate high jump performance and the use of horizontal squats for enhancing sprint starts."
J Strength Cond Res. 2011 Dec;25(12):3319-25.