Post Activation Potentiation (PAP)

At P3, a major route to improving performance is through the application of “complex training,” which involves combining high load strength movements with biomechanically similar plyometric/ballistic movements as a means of taking advantage of Post Activation Potentiation (PAP), a phenomenon that refers to enhancement of muscle function as a result of its contractile history. P3 has found that complex training is far superior in developing athletic power to either resistance training or plyometric training alone, and while there are other mechanisms involved in P3 complexes, the successful manipulation of PAP plays an important role.

Underlying Mechanisms of PAP Theory

1. Heavy loading prior to an explosive movement induces a high degree of central nervous system stimulation, resulting in greater motor unit recruitment and force, which can last from five to thirty minutes (Chiu, Fry, Weiss, et al 2003)

2. Along with more central nervous system stimulation, PAP has been attributed to Phosphorylation of myosin regulatory light chains, meaning that following a heavy strength movement actin and myosin which function together to generate force and muscle contractions are more sensitive to calcium and more active. The greater the phosphorylation of the myosin light chain protein, the faster the rate of contraction and tension (Chiu, Fry, Weiss, et al 2003).

3. Another scientific finding that explains this effect is the enhancement of the H-reflex, increasing the rate of neurotransmission to the muscles (Hodgson, Docherty, Robbins, 2005).

At P3, we have found that the increased motor unit recruitment, nervous system excitability and reflex potentiation following a high load strength movement does indeed lead to optimum conditions for subsequent explosive movements. It is important to note that when performing a heavy strength movement or max contraction there is always a trade-off between fatigue and PAP. The balance between these two determine the net effect of the following explosive movement. If the net effect of the PAP overrides the net effect of the fatigue, the athlete will perform the explosive movement with more force making it an important method for developing both acute performance adaptations and long-term performance adaptations.


Chiu, L.Z., Fry, A.C., Weiss, L.W., Schilling, B.K., Brown, L.E., & Smith, S.L. (2003). Postactivation potentiation response in athletic and recreationally trained individuals. Journal of Strength and Conditioning Research. 17(4), 671-677.

Hodgson, M., Docherty, D., & Robbins, D. (2005). Post-activation potentiation underlying physiology and implications for motor performance. Sports Medicine, 25 (7), 385-395.