Post Activation Potentiation (PAP) is a form of training many sport scientists are investing more and more time in. The notion behind it is to perform a compound movement such as the back squat, deadlift, bench press etc., followed by an explosive movement, such as a countermovement jump before resting. Theoretically the heavy loaded movement potentiates the neuromuscular system. The resultant force, therefore, should be greater (Robbins, 2005). The combination of improved strength and increased rate of force development (RFD) seems to be the key for PAP.
The Theories behind PAP
A number of theories and mechanisms have been put forward as to why PAP occurs, including increased motor neurone activity, enhanced blood flow to muscles, increased reflex electrical activity, and increased myosin light chain. On a superficial level, PAP may occur through the recruitment of more of your type 2 muscle fibres. As a result of the contractile history (1 RM backsquat + our explosive movement), our body adapts and is almost tricked into recruiting a greater percentage of fibres than previously may have been necessary. This may be the reason people often perform a better second set than their first.
Another way of examining PAP is to go deeper and explore the physiology of the muscles and determine what chemical reactions may be occurring at the time of contraction. Each muscle fibre is split up into sarcomeres and every sarcomere is filled with myofilaments which, when they slide across each other, cause contraction (Martini and Nath, 2009). PAP may be facilitated at this level through calcium – calcium plays its role during contraction, the brain signals the body to draw calcium from the blood in the muscle cells where it binds with troponin dragging the tropomyosin with it, due to the fact these two proteins are already bound. This in turn activates the actin and myosin contractile elements causing the muscle to contract. Following the back squat and explosive movement, the muscles which have just worked around their maximum capacity have become more sensitive to calcium in the body. Hypothetically more can be dragged into the muscle resulting in increased force production (Hodgson, Docherty et al. 2005).
Looking at the research available, PAP has the potential to be a great tool to be utilised in powerful activities. Long term studies examining PAP on long term adaptations are scarce, but it stands to reason that it may be a usesful tool to enhance performance.
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Martini, F. and Nath, J. (2009). Fundamentals of anatomy & physiology. San Francisco: Pearson/Benjamin Cummings.
Nsca.com, (2015). Hot Topic: Post-Activation Potentiation (PAP). [online] Available at: http://www.nsca.com/Education/Articles/Hot-Topic-Post-Activation-Potentiation-(PAP)/ [Accessed 7 Dec. 2015].
Robbins, D. W. (2005). POSTACTIVATION POTENTIATION AND ITS PRACTICAL APPLICABILITY. The Journal of Strength & Conditioning Research, 19(2), 453-458.
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