The aim of the research was to determine the possibility of predicting vertical jump height based on absolute and relative lower extremity strength. Thirty healthy and physically active male students (age: 20.84 ± 0.99 years; height: 179.46 ± 5.91 cm; body weight: 73.88 ± 6.43 kg) from the Faculty of Sports and Physical Education participated in this study. Absolute lower extremity strength was assessed using the one-repetition maximum (1RM) back squat, expressed in kilograms. Relative lower extremity strength was calculated by dividing the estimated 1RM back squat by the participants’ body weight, yielding the 1RM back squat relative to body weight (BW) (1RM/BW). Vertical jump height was measured using an Optojump system with two types of jumps: countermovement jumps (CMJ) and squat jumps (SJ). Statistically significant and moderately high correlations were observed between absolute and relative lower extremity strength variables and vertical jump height variables. Regression analysis results indicated statistically significant multiple correlations of 1RM absolute strength and 1RM/BW relative lower extremity strength as predictors of CMJ and SJ vertical jump height criteria variables. There is limited research on this topic conducted specifically on student populations, making this study a valuable foundation for future research. The research findings can serve as guidelines for the development of absolute and relative lower extremity strength, thereby contributing to improved vertical jump performance.

Abstract The aim of the research was to examine the effects of isokinetic training on knee stabilizer strength, and whether this increases the efficiency of performing basic gymnastics vaults. A total of 60 respondents, students of the Faculty of Sports and Physical Education (average age 19.7±1.5 years, weight 75.3±2.9 kg, height 179.8±6.7 cm) were included. The subjects were divided into two groups, experimental (EG) (n=30) and control (CG) (n=30). As part of the 12-week program, the experimental group (EG) in addition to exercises within the regular classes at the university had an additional concentric isokinetic training 3 times a week on the Biodex System 3 dynamometer, while the control group (CG) only had exercises within the regular classes at the university. The results showed statistically significant differences (p < 0.05) between (EG) and (CG), both, in increasing the strength of the knee stabilizers and in the performance of gymnastics vaults, and the strength of the knee extensors and flexors in favor of (EG). It can be concluded that the additional isokinetic training resulted in a greater increase in strength, but also a better performance of gymnastics vaults.

Conflict is an integral part of sport, and it implies a normal occurrence in communication and relationship between athletes and coaches. The main aim of this paper was to present a conflict analysis of the coach-athletes relationship, but also its impact on the achievement of sports results. The review article analysed nine works that directly studied interpersonal relationships between coaches and athletes. Research results suggest that conflict is evident and inevitable, as well as expected since coaches spend a lot of time with athletes, and pass through the training process, but also the competition period, when athletes are exposed to greater pressure because of the competition itself. Timely response and adequate response to conflict can greatly contribute to improving relations and even better sports results.