Post-activation potentiation (PAP)

Post-activation potentiation (PAP) is a short-lived improvement in explosive performance after heavy muscle work, such as a better jump after a heavy back squat.^{1Viada, The Ultimate Hybrid Athlete, p. 165.} A brief, intense contraction can enhance the contractions that follow, while continued work produces fatigue.^{2Hoffman, NSCA’s Guide to Program Design, p. 72.} Potentiation and fatigue occur together; their balance decides whether performance improves.^{2Hoffman, NSCA’s Guide to Program Design, p. 72.} Proposed mechanisms include greater phosphorylation of the regulatory myosin light chains and better neuromuscular function.^{2Hoffman, NSCA’s Guide to Program Design, p. 72.}

ISSA’s strength and conditioning textbook puts the gain at 2 to 10% and says the benefit is limited to experienced power athletes, with less effect in young or relatively weak ones.^{3International Sports Sciences Association, Strength and Conditioning, p. 371.}

In practice

• Viada suggests about 80% of 1RM for 3 sets of 6, leaving 2 to 3 reps in reserve, then 6 to 8 minutes of rest before the explosive exercise.^{4Viada, The Ultimate Hybrid Athlete, p. 166.}
• Heavier loads trigger PAP more reliably than light ones, but taking the heavy sets too close to failure tips the balance toward fatigue.^{4Viada, The Ultimate Hybrid Athlete, p. 166.}
• Responses vary with training experience, the client’s power-to-strength ratio and the intensity and volume of the heavy work.^{2Hoffman, NSCA’s Guide to Program Design, p. 72.}
• Pairing heavy strength exercises with lighter explosive ones in the same session is called contrast training.^{3International Sports Sciences Association, Strength and Conditioning, p. 371.}

Where sources differ

Suggested rest intervals differ: the NSCA’s program design guide cites 4 to 12 minutes for power events such as the high jump, ISSA cites 15 seconds to 5 minutes, and Viada recommends 6 to 8 minutes.^{5Hoffman, NSCA’s Guide to Program Design, p. 73.},^{3International Sports Sciences Association, Strength and Conditioning, p. 371.},^{4Viada, The Ultimate Hybrid Athlete, p. 166.} The guide notes the window likely depends on fiber type, training experience and the design of the heavy activity.^{5Hoffman, NSCA’s Guide to Program Design, p. 73.}