Effects of Plyometric Training and Beta-Alanine Supplementation on Maximal-Intensity Exercise and Endurance in Female Soccer Players

Abstract

Plyometric training and beta-alanine supplementation are common among soccer players, although its combined use had never been tested. Therefore, a randomized, double-blind, placebo-controlled trial was conducted to compare the effects of a plyometric training program, with or without beta-alanine supplementation, on maximal-intensity and endurance performance in female soccer players during an in-season training period. Athletes (23.7 ± 2.4 years) were assigned to either a plyometric training group receiving a placebo (PLACEBO, n = 8), a plyometric training group receiving beta-alanine supplementation (BA, n = 8), or a control group receiving placebo without following a plyometric training program (CONTROL, n = 9). Athletes were evaluated for single and repeated jumps and sprints, endurance, and change-of-direction speed performance before and after the intervention. Both plyometric training groups improved in explosive jumping (ES = 0.27 to 1.0), sprinting (ES = 0.31 to 0.78), repeated sprinting (ES = 0.39 to 0.91), 60 s repeated jumping (ES = 0.32 to 0.45), endurance (ES = 0.35 to 0.37), and change-of-direction speed performance (ES = 0.36 to 0.58), whereas no significant changes were observed for the CONTROL group. Nevertheless, compared to the CONTROL group, only the BA group showed greater improvements in endurance, repeated sprinting and repeated jumping performances. It was concluded that beta-alanine supplementation during plyometric training may add further adaptive changes related to endurance, repeated sprinting and jumping ability.

Short-Duration Beta-Alanine Supplementation Did Not Prevent the Detrimental Effects of an Intense Preparatory Period on Exercise Capacity in Top-Level Female Footballers

“…These data are in line with previous studies showing no effect of BA on short-duration repeated sprints in team sports players (21,22). However, previous research in female football players has shown BA supplementation to improve mean power output during repeated 30-s Wingate sprints (30) and induce greater improvements in repeated-sprint tests when combined with plyometric training compared to training alone (11). It is possible that the highly trained nature of our athletes contributed to these results, since meta-analytical data has shown well-trained individuals to achieve smaller performance gains with supplementation than non-trained individuals (17).…”

“…It is possible that the highly trained nature of our athletes contributed to these results, since meta-analytical data has shown well-trained individuals to achieve smaller performance gains with supplementation than non-trained individuals (17). The aforementioned studies recruited university level (30) and amateur (11) players, while we employed elite youth players. It is also important to again emphasise that the lack of any changes in these tests may similarly be due to the intense nature of the training program, inhibiting any potential adaptations with or without supplementation.…”

“…Beta-alanine has previously improved YoYo IR2 performance in amateur male footballers throughout a competitive season (19), although YoYo IR1 was not improved in young elite male basketball players (20). Evidence to support beta-alanine supplementation during shorter-duration repeated sprints is distinctly lacking (21-23) although supplementation alongside plyometric training did lead to greater improvements in RAST than training alone in female soccer players (11). This suggests that the combination of training and beta-alanine may be additive, something previously demonstrated with cycling sprint training (24), although no study to date has investigated the combined effect of a football-specific training period alongside beta-alanine supplementation on football-specific performance in females.…”

“…In addition to differentiating between playing standard, these tests can be used to monitor training adaptations, seasonal variation and determine differences between playing position [for review, see (9)]. The running anaerobic sprint test (RAST) is another protocol that has been shown to be reliable and valid to assess anaerobic power and is a good predictor of short-distance running performances (10) while the 20-m sprint test is a commonly used measure to assess team sport players (11). Any changes in these performance measures may be reflective of an enhanced capacity to improve in-match performance and thus are useful tools to determine the efficacy of any intervention.…”

Sequencing Effects of Plyometric Training Applied Before or After Regular Soccer Training on Measures of Physical Fitness in Young Players

“…Previous recommendations have also suggested that PJT should be conducted prior to regular (technical-tactical) training sessions (7,14) so that PJT drills are not performed in a fatigued state (26), to maximize neuromuscular responses. Based on this premise, PJT has usually been applied at the beginning of training sessions (34,37,42). However, PJT has also been implemented after regular workouts.…”