Unless you’ve been living under a rock, you’ve probably heard about post-activation potentiation (PAP). But despite the extensive research done as of late, we still need more information on whether PAP works for athletic events that are mostly aerobic. This topic was covered in a recent Journal of Strength and Conditioning study.
Just in case you have been living under the aforementioned metaphorical rock, let me briefly explain what PAP is. The basic idea is that performing an intense bout of exercise will increase performance in a subsequent activity, as long as the muscles used are similar in both exercises. There seems to be an ideal window where there is no fatigue left over from the first exercise, but the nervous system is still primed and ready for exercise.
Because of the neurological component of PAP, it stands to reason it might not work so well on aerobic endeavors. Endurance exercise, like a 5km foot race, or, as in the Journal study, a 20km cycling effort, is limited to a much greater extent by aerobic metabolism than a peak power or skill effort, which has a much more substantial neurological component.
The participants of the study were eleven trained and experienced cyclists. They were already familiar with the type of testing performed in this study. Each participant was first evaluated on the leg press. The goal was to determine their five rep max (5RM). This was then to be used as the PAP exercise for the subsequent 20km cycling test. Using their 5RM as a starting point, the cyclists did four sets of leg press until concentric fatigue in the PAP condition. They then rested for ten minutes before the 20k time trial. When they performed the control condition, they did nothing before the time trial. The researchers drew blood, tested for oxygen utilization, and measured power output and perceived exertion.
Out of the studied factors, a few important ones were improved. Cycling economy, which is the energy required to maintain a particular pace, was improved in the PAP condition. Also, interestingly, the PAP increased power output for the first ten percent of the trial. This would suggest the limits of the time that PAP is effective, as mentioned earlier. It also means the PAP benefit extended through the ten-minute rest period and then perhaps a further two or three minutes into the time trial.
The most important factor that improved was time. The PAP participants clocked a 6.1% faster time than the control group, or an average of 1.5 minutes over a nearly thirty-minute effort. Over a 20km cycling time, an improvement of that degree is substantial. The improvement could have made the difference between first place and middle of the pack.
These improvements occurred in spite of no difference in physiological factors, like blood lactate. Keep in mind also, that there was no difference in perceived exertion. In other words, if you try out PAP, your efforts might feel the same, but rest assured your performance is improving.
References:
1. Renato Silva, et. al., “Acute Prior Heavy Strength Exercise Bouts Improve the 20-Km Cycling Time Trial Performance,” Journal of Strength and Conditioning Research, DOI: 10.1519/JSC.0000000000000442
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