Effects of two explosive strength circuits on power, speed and agility in U16 football players

The purpose of study was to examine the effect of two circuits, which consists in specific plyometric drills and football-specific sprints combined with technical elements (crosses and finishing from crosses, feint, dribble and shoot), on the performance level related to explosive strength, power, speed and agility in U-16 football players. Forty U16 junior football players were selected to participate in this study (20 in the experimental group and 20 in the control group). For the experimental group was applied a weekly training programme (the experimental intervention), which consisted in two specific explosive strength circuits with sprints on four and three pitch zones. The tests consisted of vertical jumps – squat jump, counter movement jump and 15” Bosco Repeated Jump Test, drop jump, 10 m, 20 m and 30 m linear sprints and the Illinois Agility Test. The experimental group showed performance improvements (p < 0.05) in all explosive strength and power tests, while the increases of the control group were not statistically significant. At speed and agility tests (10 m, 20 m and 30 m sprints and the Illinois test), the experimental group showed significant performance improvements for the 10 m, 20 m and 30 m sprints, and for Illinois Agility Test (p < 0.05). The observed differences between the experimental and the control group (at initial and final testing) were discussed, and recommendations regarding the effectiveness of the intervention programme were highlighted.