Essential Role of Weekly High-Frequency Plyometric Training to Enhance Physical Performance and Manage Muscle Soreness in Male Adolescent Soccer Players.

To investigate the effects of volume-matched plyometric training (PT) with different frequency distributions on physical performance and muscle soreness in adolescent soccer players. Thirty-four subelite players were allocated into 2 groups: PLYO-1 (n = 17, age = 16.02 [0.26] y) underwent 1 PT session per week, while PLYO-3 (n = 17, age = 15.81 [0.37] y) underwent 3 volume-matched PT sessions per week. The PT program lasted 9 weeks with an initial weekly volume of ∼55 foot contacts, increasing by 10% per week. A 7-point Likert scale was employed to assess perceived muscle soreness before and after each PT session. All players were tested for countermovement horizontal and vertical jumps, 10-m sprint, and change-of-direction (COD) performance using the modified 505 test (505mod). After the 9-week experimental period, both groups exhibited significant improvements in countermovement horizontal-jump distance (P < .001; d = -0.55) and countermovement vertical-jump variables (jump height and modified reactive strength index, P < .001; d = -0.34 and d = -0.33), and 505mod time (COD deficit) (P < .001, d = 1.09). However, no improvements were observed in the 10-m sprint time for PLYO-1 and PLYO-3 (P > .911, d = -0.12). The changes in perceived muscle soreness were significantly lower for PLYO-3 compared with PLYO-1 (P < .001, d = 1.04) throughout the experimental period. Employing weekly volume-matched PT conducted at different frequencies can help to maintain, or even enhance, jump and COD performance while differently impacting muscle soreness.