TY - JOUR T1 - Postactivation potentiation: role in performance JF - British Journal of Sports Medicine JO - Br J Sports Med SP - 386 LP - 387 DO - 10.1136/bjsm.2002.003392 VL - 38 IS - 4 AU - D Sale Y1 - 2004/08/01 UR - http://bjsm.bmj.com/content/38/4/386.abstract N2 - The role of postactivation potentiation in enhancement of strength and speed performance requires further research Postactivation potentiation (PAP), also known as activity-dependent potentiation, is an increase in muscle isometric twitch and low frequency tetanic force following a “conditioning” activity.1,2 Examples of conditioning activity are a series of evoked isometric twitches (staircase or treppe), an evoked isometric tetanic contraction (post-tetanic potentiation), a sustained isometric maximal voluntary contraction (MVC), and a series of dynamic contractions. In fact, any type of contractile activity is likely to activate the mechanism of PAP—that is, phosphorylation of myosin regulatory light chains, which increases Ca2+ sensitivity of the myofilaments.2 The result is an amplified level of myosin cross bridge activity in response to submaximal concentrations of myoplasmic Ca2+. A notable feature of PAP is that it has no effect on the force of high frequency tetanic isometric contractions, because in such contractions a “saturating” concentration of Ca2+ is attained, making any increase in Ca2+ sensitivity inconsequential. Although less studied, PAP also increases the force of shortening (concentric) contractions,3 and the highest frequency at which PAP is effective is greater for rapid shortening (concentric) contractions than for isometric contractions.4 On the basis of the foregoing, it would appear that PAP … ER -