Post Activation Potentiation and Concentric Contraction Performance: Effects on Rate of Torque Development, Neuromuscular Efficiency, and Tensile Properties

Abstract Gago, P, Zoellner, A, Cezar, J, and Ekblom, MM. Post activation potentiation and concentric contraction performance: effects on rate of torque development, neuromuscular efficiency and tensile properties. J Strength Cond Res 34(6): 1600–1608, 2020—This study investigated how a 6-second maximal voluntary isometric contraction (MVIC) conditioning affected plantar flexor twitch rate of torque development (RTD TW ), as well as peak torque (PT CC ) and rate of torque development (RTD CC ) of maximal voluntary concentric contractions (MV CC ) performed at 60°·s −1 . RTD CC and normalized triceps surae electromyography signals (EMG TS ) were measured during different phases of contraction. In addition, muscle tendon unit passive stiffness index (SI) calculated from the torque-angle relation was measured after each MV CC . Enhancements were found in the RTD TW immediately (by 59.7%) and up to 480 seconds (by 6.0%) after MVIC ( p < 0.05). RTD CC during the 100–200 ms, 50–200 ms, and 0–200 ms phases and PT CC were enhanced (by 5.7–9.5%) from 90 to 300 seconds after conditioning ( p < 0.05). Neuromuscular efficiency increased (decreased EMG TS /RTD CC ) in the 50–200 ms and 0–200 ms phases by 8.8–12.4%, from 90 to 480 seconds after MVIC ( p < 0.05). No significant changes were found in the SI or in RTD CC during the 50–100 ms phase, suggesting that the enhancements reported reflect mainly contractile rather than neural or tensile mechanisms. PAP effects on PT CC and RTD CC were significant and more durable at a lower velocity than previously reported. Enhancement in RTD CC and neuromuscular efficiency were found to be more prominent in later phases (>100 ms) of the MV CC . This suggests that enhanced contractile properties, attained through MVIC, benefit concentric contraction performance.