The Relationship Between Reactive Strength Index and Acceleration, Sprint, Change of Direction Performance and Leg Strength in Football Players: Descriptive Research

Abstract

The aim of this study was to determine the relationship between reactive strength index and leg strength, acceleration, sprint, change of direction and eccentric utilisation rate parameters of young football players. Material and Methods: A total of 23 football players who competed in the U17 league in the 2022-2023 season voluntarily participated in the study. Height and body weight measurements were used to determine the physical parameters of the footballers and right-left leg strength, drop jump, countermovement jump, squat jump, 10 m acceleration, 40 m sprint and illinois agility tests were used as performance tests. Reactive strength index and eccentric utilisation ratio were calculated with the data obtained from jump tests. The normal distribution of the data was analysed by Shapiro-Wilks test and the relationship between the variables was determined by Pearson correlation test. Results: Significant relationships were found between reactive strength index and eccentric utilisation ratio (r=0.547; p<0.05), right leg average strength (r=0.451; p<0.05) and left leg average strength (r=0.436; p<0.05). No significant correlation was found between reactive strength index and acceleration, sprint, change of direction and right-left leg peak strength performances (p>0.05). Conclusion: In conclusion, it can be suggested that the reactive strength index parameter should be taken into consideration in the evaluation process of strength and eccentric utilisation rate of young football players.