Tart Cherry Juice Effects on Exercise-Induced Damage and Performance in Female Collegiate Soccer Players.

Abstract

Soccer match-play induces oxidative stress, inflammation, and muscle damage, collectively known as exercise-induced damage (EID). Prolonged damage may hinder performance in succeeding games played within 48 hours, which is common during the season. This study tested the hypothesis that a phytonutrient intervention known to reduce oxidative stress and inflammation would attenuate exercise-induced damage and improve performance during high-intensity training or match-play. PURPOSE: To determine the effects of short-term tart cherry juice consumption on EID and performance in female collegiate soccer players. METHODS: Participants were randomized into 3 groups: tart cherry juice (TCJ, n=10), placebo (PLA, n=10), and control (CON, n=5). TCJ and PLA groups consumed 8 fl. oz. of tart cherry juice or a cherry-flavored placebo, twice per day for 7 days while the CON group received no treatment. On day 5, participants underwent a high-intensity training session designed to generate EID. Markers of oxidative stress (urinary 8-isoprostanes), inflammation (plasma IL-6), and muscle damage (serum creatine kinase) were measured at baseline, on day 5 post-exercise, and on day 7 (recovery). Performance indicators (50-y sprint, single-leg bound test, and 300-y shuttle) were measured pre- and post-intervention (day 0 and day 7). RESULTS: IL-6 and urinary 8-isoprostanes (normalized to creatinine) increased significantly in all groups in response to the high-intensity training session on day 5 (p<0.05); however, there were no differences between groups. None of the performance measures changed from pre- to post intervention and there were no group differences. CONCLUSIONS: Contrary to our hypothesis, the tart cherry juice did not modify the oxidative stress and inflammatory response as compared to placebo or control. Therefore any differences in performance attributable to lower EID would not be seen. Duration of the intervention and the timing of consumption need further investigation.