A study was recently performed to investigate the effect of a 10-week combined resistance-plyometric training program on muscular strength, running economy, and VO2 max in female soccer players. Resistance and plyometric training programs have demonstrated improvements in running economy in trained and untrained adults in the absence of improvements in max oxygen consumption. There is a general consensus in literature regarding the efficacy of strength-plyometric training to improve running economy, and there is a lack of evidence pertaining to studies on females, specifically female soccer athletes. To the best of the researcher’s knowledge, this was the first study to investigate the effect of a resistance-plyometric training program on VO2 max and running economy in Division I female soccer players.1
There were 15 Division 1A female soccer players who participated in the study, but only 11 were included in the final analysis. Each participant performed a treadmill test at the end of competitive season, and after a 10-week training program to determine VO2 max and running economy. The isometric strength of each player was measured in both knee flexion and extension. Each player participated in resistance training two days a week on non-consecutive days. Each session lasted approximately 60 minutes, and was preceded by a short warm-up/stretching session. The session consisted of 9-10 exercises of 3 sets each. The plyometric training was conducted twice a week on different non-consecutive days from the resistance training. The drills for the training varied between days; an emphasis on speed and quickness on one day, followed by plyometric-agility training on a separate day.2
The dependent variables were maximal oxygen consumption (VO2max), time-to-fatigue during VO2max protocol, interpolated maximal speed of highest completed stage during VO2max protocol, running economy at 9 km·h−1, percentage of VO2max at 9 km·h−1, and isometric knee flexion and extension.3
The results of the study revealed there was a significant increase in VO2 peak (10.5%), time to fatigue (6.9%), and interpolated max speed (3.6%). All of these increased despite there being a decrease in the maximal respiratory exchange ratio (2.9%). There was no significant change in the running economy at 9 km/hr, but there was a significant decrease in the percentage of the VO2 peak at 9 km/hr. The max isometric strength of the knee flexors and extensors did not change.4
The results from this study suggest a plyometric-agility training program may increase the VO2peak in female soccer players; however, the effect on running economy still remains unclear.
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