## 4 Discussion
### Acute Effects
In this regard, the literature suggests that ballistic exercises can generate greater activation of type II muscle fibers, as well as greater power, due to high levels of acceleration throughout the full range of motion [64; 75; 76], unlike non-ballistic exercises that are characterized by having a deceleration phase that can affect the speed of movement and consequently power production [75]. Conversely, ballistic exercises can generate less fatigue than exercises with high loads [45]. For this reason, BE could be more effective than HRE to induce PAPE; however, in both studies [59; 63], both exercise modalities similarly improved exercise punch performance, with no differences in recovery time between both modalities. Similar to the findings of [PERSON] et al. [77] and [PERSON] et al. [78] who reported that performance in a throwing test can be increased after performing five consecutive drop jumps or three repetitions of a hang clean and jerk at 80% of 1 RM. This supports the idea that BE can generate PAPE to a similar degree as HRE. The potentiation generated by both training modalities may be due to a high recruitment of motor units that comprise type IIX muscle fibers during the exercises performed [64; 75]. In addition, the nature of ballistic exercises allows the generation of neuromuscular activity in a few milliseconds, resulting in greater power production [75; 79]. Therefore, the findings on the improvement of punch force and speed in the studies by [PERSON] et al. [64; 65] could be illustrated by the described mechanisms. At this point, both BE and HRE can be considered as part of the warm-up session to improve punches' performance during competition or specific sparring sessions. However, it is important to consider that this requires an optimal recovery time, which needs to be individualized for each athlete [46; 71]. Finally, the findings of [PERSON] et al. [59], who reported improvements in the impact strength of straight punches and hook punches with both hands, suggest that a punch-specific isometric exercise may be a more useful activity to perform during warm-up than a specific striking exercise with a resistance band to acutely improve striking performance in amateur boxers. Although both exercises managed to acutely improve punches' performance, the specific isometric exercise was slightly superior. In this regard, the execution of a maximum voluntary contraction at specific joint angles in a ballistic manner has been shown to potentially improve variables such as RFD and speed in long-term training research [80; 81]. According to [PERSON] et al. [59], increases in punch force and RFD after specific isometric exercise may be due to increased neuronal activity; however, this was not evaluated in the study. Moreover, there is a possibility that specific isometric exercise through maximum voluntary contraction improves the \"effective mass\" during punches. In this sense, [PERSON] et al. [82] reported a double peak of muscle activation during striking techniques, due to the activation, relaxation and reactivation of the muscle groups involved, beginning with an electromyography (EMG) peak (indicating muscle activation) when the movement was initiated, then a drop in EMG throughout the movement and a final EMG peak, moments before impact, where a \"hardening\" of the body occurs at the moment of impact, thus creating effective mass and reduction in the loss of energy during the impact of the punch. In this sense, an increase in muscle co-contraction around a joint can cause a reduction in the deformation observed during impact, allowing for a greater total effective mass at the impact of the punch [81]. Furthermore, the more segments the athlete involves in the kinetic chain of the movement, the greater the potential to improve effective mass [82]. However, previous studies [6; 83] have encouraged the use of isometric contractions to improve this \"stiffness\" in the final range of the punch in boxers.