Effect of force-velocity deficite on acceleration kinematics at soccer players

Objective: The aim of this study is to investigate the effects of force (F) and speed (V) deficiency on the sub-stages of acceleration during 20m sprint. Method: 26 male (age: 16-19) licensed athletes were attended in the study and divided into two groups: velocity deficiency (Vd) (n = 12) and force deficiency (Fd) (n = 14). Physical characteristics, anthropometric properties, squat height values of the athletes were determined and two repeated squat jumps were applied with random loads (0-20-40-50 kg). One week later the athletes, 15 minutes after the general and special warming, including two repetitions 0-5 m (t5m). 0-10 m (t10m), 0-20 m (t20m), 0-30 m (t30m) and 0-40 m (t40m) running test was applied. Results: The physical characteristics, anthropometric properties and sprint times (5m, 10m, 20m 30m 40m) of Vd and Fd groups were not statistically different. While all stride parameters were different between the groups in the second phase of acceleration, especially the stride velocity and stride length parameters were statistically significant in the first phase of acceleration. Conclusion: In the group with better velocity characteristics(Fd), it was determined that the acceleration stages occurred at shorter distances and faster. This transition is achieved by increasing the stride length and stride velocity. Although they have similar stride velocities, the group with a higher force characteristic in the second phase of acceleration was able to transfer its force parameter forward in a better way. Key words: force-velocity relationship, acceleration, 20 m sprint, soccer