Final answer:
Research on post-activation potentiation confirms that the effect is highest after a heavy conditioning set due to increased muscle sensitivity and recruitment of myofibers, confirming the statement is True.
Step-by-step explanation:
The statement that research surrounding post-activation potentiation suggests the effect after a heavy conditioning set is highest is True. Post-activation potentiation (PAP) refers to the phenomenon where muscle force output is temporarily enhanced as a result of a conditioning contraction. This occurs due to increased phosphorylation of myosin regulatory light chains, which makes the muscle more sensitive to calcium, and thus increases its ability to produce force. The extent of potentiation highly depends on the fitness level of the individual and the rest interval between the conditioning contraction and the subsequent performance.
Furthermore, the primary variable in determining force production is the number of myofibers within the muscle that receive an action potential. High-intensity stimuli, like lifting a heavy weight, increase the number of recruited myofibers, leading to greater force production. Additionally, recruitment of all available myofibers and subsequent potentiation of their contractile response can result in maximal force output, as seen during activities requiring extreme strength.