Effects of an 8-week Plyometric Training Programme on Sprint, Jump, and Agility Performance in Recreational Male Football Players Aged 14-16 Years

Primary outcomes

1. Change in 30 m sprint time

   Time frame: Baseline and immediately after the 8-week intervention

   Sprint performance was assessed using the 30 m sprint test. Time was recorded in seconds using photocell timing gates. Lower values indicate better sprint performance.

2. Change in vertical jump height

   Time frame: Baseline and immediately after the 8-week intervention

   Vertical jump performance was assessed using the My Jump 2 application. Jump height was recorded in centimetres. Higher values indicate better jump performance.

3. Change in 505 agility test time

   Time frame: Baseline and immediately after the 8-week intervention

   Change-of-direction performance was assessed using the 505 agility test. Time was recorded in seconds. Lower values indicate better agility performance.

4. Change in standing long jump distance

   Time frame: Baseline and immediately after the 8-week intervention

   Horizontal jump performance was assessed using the standing long jump test. Jump distance was recorded in centimetres. Higher values indicate better horizontal jump performance.

5. Change in quick feet test time

   Time frame: Baseline and immediately after the 8-week intervention

   Footwork performance was assessed using a 10 m ladder-based quick feet test. Time was recorded in seconds. Lower values indicate better footwork performance.

6. Change in zig-zag running test time

   Time frame: Baseline and immediately after the 8-week intervention

   Multidirectional running performance was assessed using the zig-zag running test. Time was recorded in seconds. Lower values indicate better multidirectional movement performance.

7. Change in body mass index

   Time frame: Baseline and immediately after the 8-week intervention

   Body mass index was calculated from measured body mass and height and reported as kg/m².