Impact of Powdered Tart Cherry Supplementation on Performance Recovery Following Repeated Sprint Exercise.

BACKGROUND: Due to its high polyphenol content and purported capability to mitigate post-exercise muscle soreness and promote recovery, tart cherry (TC) supplementation has been proposed to enhance recovery and athletic performance. This study examined the effects of powdered TC supplementation on various recovery and performance metrics following a repeated sprint exercise protocol in physically active young adults. METHODS: 40 (18 M, 22 F) healthy, active participants (24.6 ± 5.5 yrs, 171.5 ± 11 cm, 71.7 ± 14.5 kg, 24.2 ± 3.1 kg·m(-2)) participated in this randomized, double-blind, placebo-controlled, parallel study design. Placebo (PLA) or powdered TC supplementation (500 mg/day) occurred for ten days: seven days prior to, day of, and two days following repeated sprints (15 × 30 m with 1 min rest between sprints). Performance was assessed via the countermovement jump, isometric mid-thigh pull, isokinetic knee extension, and the Wingate anaerobic test. Recovery was evaluated using visual analog scales for soreness, recovery, and readiness to train. Muscle damage was evaluated using creatine kinase. These measures were evaluated at baseline, and at 1 h, 24 h, and 48 h post-exercise. RESULTS: Significant main effects of time were observed with recovery VAS (p < 0.001), readiness to train VAS (p < 0.001), and jump height (p = 0.014) experiencing similar reductions, while soreness VAS (p < 0.001) and creatine kinase (p = 0.05) experienced similar increases in response to the repeated sprint protocol and supplementation. Across all measurements, no significant group × time differences were observed for jump height (PLA:-6.7 ± 10.4% vs. TC: -11.0 ± 17.9%, p = 0.608), peak propulsive force (PLA: 0.3 ± 4.6% vs. TC: 2.2 ± 7.4%, p = 0.194), knee extension peak torque at 180°/s (PLA: 10.5 ± 73.5% vs. TC: -1.04 ± 49.6%, p = 0.335), readiness to train VAS (PLA: -23.0 ± 19.2% vs. TC: -14.7 ± 20.2%, p = 0.401), soreness VAS (PLA: 250 ± 323% vs. TC: 261 ± 432%, p = 0.838), recovery VAS (PLA: -24.6 ± 17.9% vs. TC: -8.2 ± 40.5%, p = 0.251), and creatine kinase (PLA: 22.8 ± 35.5% vs. TC: 90.4 ± 225.6%, p = 0.31). CONCLUSIONS: A single bout of repeated sprints was responsible for significant reductions in jump height, peak propulsive force, peak torque, and perceived readiness, while perceived soreness, myoglobin, and creatine kinase were significantly increased. Ten days of TC supplementation did not impact any change beyond what was observed in PLA for markers of recovery, readiness, soreness, exercise performance, and markers of muscle damage.