Plyometric Training, in the Improvement of Explosive Strength and Speed in Soccer Players

Football requires a high number of actions at high speed and intensity. The application of plyometrics can improve explosive strength and speed levels in soccer players. The main objective of the study is to assess the effectiveness of a program based on plyometric exercises for the improvement of the explosive force in vertical jump and the speed in running with and without the ball in soccer players of youth category. Randomized clinical study, simple blind, with follow-up period. 30 players will be randomized to the study groups: experimental and control. The intervention will last 4 weeks, with 2 weekly sessions lasting 20 minutes. The study variables will be: Vertical Countermovement Jump Test with Arms and Twenty-Centimeter Drop Jump Reactive Strength Index (Explosive Force), running speed without ball and ball (20 meter speed test), hitting speed of ball (Maximal Kicking Velocity Test), hamstring extensibility (Sit and Reach Test) and sural triceps extensibility (Leg Motion Basic). Normality will be calculated using an analysis of Kolmogorov Smirnov. With the t-student test the differences between assessments will be calculated and with an ANOVA of repeated measures, the effect between intersubject will be calculated. The effect size will be obtained with Cohen's formula. It is expected to obtain an improvement in the explosive force in the vertical jump, as well as in the running speed with and without the ball.