Evaluating the Effects of Consecutive Phases of Plyometric Jump Training on Athletic Performance in Male Soccer Players: The Effect of Training Frequency and Volume Manipulations

Purpose: This 14-week, two-phase study aimed to determine the relative effects of 1-day or 2-days of volume-matched plyometric training on athletic performance (10 m and 40 m sprints, change of direction, vertical jump) in male soccer players (Phase 1). The objective of Phase 2 was to determine the relative effects of higher- and lower-volume plyometric training protocols in maintaining any previously attained increases in athletic performance from Phase 1. Method: A randomised parallel-group trial design was utilised. In Phase 1, participants (n=24; mean age: 19.5 ± 1.2 yrs; mean height: 179.7 ± 7.1 cm; mean weight: 69.8 ± 6.9 kg) were randomly allocated to one of two groups to receive either 1-day or 2-days of volume- and intensity-matched plyometric training for a 7-week period. For the second 7-week period (Phase 2), half of each group was randomized into either a lower volume or higher volume plyometric training group. Results: In Phase 1, both the 1-day group and 2-day groups attained comparably significant (p<0.001) increases in performance in all fitness tests ranging from effect sizes (d) of 0.4 (95% CI: 0.11 to 0.70) for 10 m sprint to 1.51 (0.42 to 2.60) for vertical jump. There were no significant differences between the performance increases in the two groups. In Phase 2, neither group increased or decreased performance, maintaining all previously attained increases with only trivial effect sizes observed (-0.02 [-0.58 to 0.53] to 0.11 [-0.38 to 0.61]). Conclusion: Increases in 10 and 40 m sprint speed, change of direction speed and vertical jump height can be achieved and maintained with as little one plyometric training session per week. Sessions can include 120 jumps to induce increases of the reported magnitudes with 60 jumps to maintain these increases thereafter, in male soccer players.