## 1 Introduction
Applying the PAPE effect as a tool to counteract this issue involves consciously using active rest periods that include a conditioning activity (CA) aimed at stimulating the neuromuscular system for more effective performance in subsequent efforts [26]. Literature suggests that even one set (or a few sets) with a high but submaximal load, performed at a specific tempo and with a precisely selected time interval between the CA and the main task, may be sufficient for short-term improvement in bench press performance parameters [27,28]. A very important component here is the timing between the conditioning activity and the execution of the target effort, which has varied in studies from 3 to even 10 min. Optimizing this interval largely depends on individual factors, such as training level, current state of the nervous system, and previous experience with high-intensity training [7]. Key determinants of concentric phase performance in the bench press include power output and barbell velocity parameters. The PAPE effect can effectively influence all these metrics; however, there is currently limited scientific literature defining optimal durations for the conditioning activity or describing a clear protocol for selecting methods that elicit this effect. For instance, some studies have employed sets with 70-80% 1 RM combined with short (3-4 min) or moderate (5-8 min) rest intervals, resulting in peak velocity increases by more than ten percent in the subsequent set [29; 30]. Others have used blood flow restriction (BFR) with slightly lower loads (20-50% 1 RM), aiming to stimulate motor units through tissue hypoxia and thus increase barbell velocity in subsequent attempts [31; 32; 33]. However, the results of these experiments are often inconsistent, which further complicates the ability to draw uniform conclusions. From a practical training perspective, the choice of the optimal method for inducing the PAPE effect should consider not only the current phase of the training cycle but also the type of target effort (short and intense sets vs. longer strength endurance efforts), as well as the individual specificity of the athlete (e.g., training level, potential health limitations). Although the PAPE concept is not entirely new, it has only recently gained popularity in bench press research, highlighting the need for an updated and synthesized understanding of the current scientific evidence. Despite the growing number of publications on this phenomenon, there is still a lack of a consistent and detailed systematic review synthesizing knowledge on the effects of PAPE protocols on barbell velocity in the bench press among trained individuals (including advanced and elite athletes). Previous studies have often been fragmentary, discussing PAPE effects in various exercises (e.g., jumps, squats) while neglecting the bench press. Moreover, there is a lack of comprehensive analysis of differences in outcomes based on rest intervals, applied loads, number of sets, and the presence (or absence) of a control group. Therefore, the objectives of this systematic review are as follows:  
* To identify and compile available studies assessing post-activation performance enhancement (PAPE) protocols in the bench press among trained individuals (paying particular attention to advanced and recreationally trained populations). * To analyze the impact of the applied conditioning activities (CAs) on barbell velocity (peak velocity, mean velocity), and--where data are available--on power parameters (peak power, mean power). * To determine the key moderating factors influencing the effectiveness of PAPE protocols, such as the type of CA, rest interval between CA and the target effort, applied load magnitude, number of sets, and participants' training experience.