Potential with Overspeed for Jump Height Enhancement: An Analysis of Factors Distinguishing Responders from Non-Responders  
[PERSON]  
1 Faculty of Physical Education and Sport, Wroclaw University of Health and Sport Sciences, I.J. Paderewskiego 35, 51-612 Wroclaw, Poland; [EMAIL_ADDRESS]
immediate performance enhancement has been studied in various CA protocols, including dynamic [10, 11] and isometric actions [12]. In resistance exercises, an external load intensity of 60-90% 1 RM with low repetitions and sets, or isometric contractions for 3-5 s in a few sets, is recommended. Performance improvements are typically seen after 3 min, with optimal effects after 7-10 min [4, 10, 13]. Additionally, pyometric exercises, such as differential bouts of jumps, have shown potential for enhancing performance in the upper and lower body as well [6, 14, 15]. The mechanisms underlying the PAPE effect in response to pyometric exercises are attributed to the stimulation of the nervous system and the concurrent reduction in the energy expenditure of the working muscles [5]. However, in terms of using pyometrics for acute performance enhancement, less is known about the usefulness of assisted band jumps, which are classified as an overspeed exercise [16]. Overspeed exercises are employed to help individuals break through velocity barriers that they cannot normally achieve. This can be accomplished by reducing body mass, such as using elastic bands that provide assistance during jumps [16]. These exercises enable faster movements and enhanced jumping capability by decreasing effective mass and increasing peak acceleration [17]. Overspeed exercise as CA remains relatively unexplored; thus, long-term effects in jump improvement have been seen [15, 16, 17]. Short, fast contractions in these exercises utilizing elastic energy during the stretch-shortening cycle require low energy expenditure, minimizing fatigue while maintaining neural activation, potentially enhancing subsequent performance [17]. [PERSON] et al. [18] conducted tests on the effects of overspeed exercises both on countermovement jumps (CMJ), which use the stretch-shortening cycle, and squat jumps (SJ), which involve only a concentric phase. They found similar improvements in jumps after overspeed training. However, the increase in CMJ height did not align with changes in power output. The authors suggested that alterations in the movement pattern during CMJ might explain the observed results. Therefore, concentric testing may be more appropriate for better assessing potential changes in performance. Individual responses vary for CA; factors influencing these differences are still being explored [9]. CA effectiveness may depend on baseline performance levels, strength, and training experience [8, 19, 20]. For example, [PERSON] et al. [21] found that while some individuals improve jump height with the same ploometric protocols, others do not respond or perform negatively. Using loaded back squats, [PERSON] et al. [22] showed that stronger individuals (greater muscular strength) gain more benefits after CA. In this context, [PERSON] and [PERSON] [8] showed that weaker individuals may benefit more from lower loads. These terms raise the question of how pyometric overspeed exercise-assisted band jumps affect individual response performance, which can vary. Also, the type of CA may bring various results [8, 21]; therefore, it seems interesting to resolve this issue due to the lack of observation regarding overspeed exercises. It could be suspected that due to the relatively low external load, potentially weaker individuals may react positively, but it remains open to whether this stimulus will be enough for those with greater muscular strength. Also, other factors, such as the eccentric utilization ratio or limb symmetry index, potentially affect performance but remain unexplored in terms of PAPE effects [23, 24]. Studies that consider factors affecting PAPE effects remain unexplored due to morphological factors.