## 1 Introduction  
The study of the effects of two flyometric training interventions over an eight-week preparatory period on straight punch impact force, cardiovascular fitness, and muscle strength in national-level boxers. Twenty male professional boxers participated voluntarily, with an average age of 22.64 \(\pm\) 3.12 years and an average training experience of 5.11 \(\pm\) 0.88 years. Their mean body weight and height were 70.20 \(\pm\) 10.13 kg and 184.28 \(\pm\) 5.38 cm, respectively. The participants were randomly assigned to two groups. Group 1, the Plyometric Stair Jump group, consisted of ten male boxers, while Group 2, the Plyometric Reaction Box Jump group, also included ten male boxers. To assess maximum punching velocity (PVmax), an accelerometer was embedded within the boxing glove, capturing data during three maximal-speed jabs with each arm to evaluate both rear-arm (RA) and lead-arm (LA) punches. Upper-body strength was assessed using a one-repetition maximum (1 RM) bench press (BP) test, while maximum velocity at various percentages of 1 RM was recorded via a linear encoder. Significant correlations were observed between the right arm punch velocity maximum (RA PVmax) and the bench press velocity at all submaximal intensities in both intervention groups (\(p\) < 0.05). However, no correlation was found between left arm punch velocity maximum (LA PVmax) and bench press velocity at any intensity within the Plyometric Reaction Jump (PRJ) group. Conversely, in the Plyometric Stair Jump (PSJ) group, a velocity at 80% of 1 RM was the sole significant predictor of RA PVmax at submaximal bench press intensities. Adjusting for the strength-to-weight ratio significantly influenced the predictive values in intergroup comparisons (\(p\) < 0.005). These findings suggest that high-load bench press exercises (e.g., at 80% 1 RM) may serve as reliable predictors of performance in specific boxing movements. However, since no significant relationship was observed with LA PVmax in this study, further research is warranted to identify exercises and intensities that may explain left arm punch velocity. **Keywords:** combat sports; performance; jump; punch speed; high performance; rear arm; lead arm  
## 1 Introduction  
Boxing has a rich Olympic history and a large professional following worldwide. Athletes must develop physical strength and technical and tactical skills to reach a competitive level. In this context, the main factors determining a boxer's performance include aerobic and anaerobic capacity, strength, endurance, and speed [1]. Aerobic capacity, enabling sustained performance during prolonged low- to moderate-intensity exertion, and anaerobic capacity, facilitating short-duration, high-intensity efforts, collectively underpin the physiological demands of boxing; therefore, an optimal balance between these two capacities is essential to achieve peak performance in the sport [2]. In boxing, athletes expend short bursts of high-intensity physical effort. During each round of a match, fighters aim to gain an advantage over their opponent through rapid and explosive movements. Such actions require the activation of the anaerobic energy system [3]. Studies have highlighted the significant impact of anaerobic endurance on boxing performance. In addition, boxers must have sufficient aerobic capacity to replenish their rapidly depleting energy reserves during the match. However, short rest periods (usually 1 min or less) do not allow for complete recovery. Therefore, increasing anaerobic endurance becomes critical in accelerating recovery between high-intensity movements, especially with brief rest intervals [4]. In a study conducted by [PERSON] et al. (2016) [5], VO\({}_{2}\) uptake in experienced male boxers during laboratory-based sparring and pad work tests was found to range between 41 and 43 mL\(\cdot\)kg\({}^{-1}\cdot\)min\({}^{-1}\), which corresponded to approximately 70% of the boxers' VO\({}_{2}\) peak.