Efficacy of Tart Cherry Juice in Reducing Muscle Injury and Biomarkers of Muscle Damage Among Healthy Adults

Numerous antioxidant and anti-inflammatory agents have been identified in tart cherries, and a study among healthy, non-exercising individuals demonstrated that tart cherries decreased post-exercise weakness and muscle pain. The purpose of this study is to assess the analgesic and myoprotective effects of tart cherry juice among healthy subjects in a randomized, placebo controlled, double-blind, crossover design trial. Fifteen healthy individuals will perform a bout of eccentric elbow flexion contractions (2 x 10 near maximum), and will then ingest 10 fl oz of a cherry juice or a placebo juice twice a day for four days, beginning immediately post exercise. Before and after exercise, and for three days following the eccentric exercise, blood will be drawn to measure serum biomarkers of muscle damage and muscle soreness will be recorded. The protocol will be repeated after a 9-10 day washout period with subjects consuming the alternative juice for the second trial. The opposite arm will perform the eccentric exercise for the second bout to avoid the repeated bout protective effect. The study's outcomes are 1) to assess changes in serum biomarkers of muscle damage, and 2) to assess changes in muscle soreness.

Inclusion criteria

• no regular upper body strength training
• no elbow flexor pain, no history of elbow or shoulder injury
• ability and willingness not to take any anti-inflammatory or pain relieving drugs during the course of the study, not to seek any other treatment for any symptoms of muscle damage directly resulting from the exercises performed as part of the study, and not to exercise their upper extremities during the study.

Exclusion criteria

• individuals who have used or are using antiepileptic drugs for pain, acupuncture, or transcutaneous electrical nerve stimulation within 3 weeks before enrollment
• recent use (within 5 half-lives) of topical medications/anesthetics, muscle relaxants, tender point anesthetic injections within 2 months
• systemic steroid use within 3 months
• any investigational drug/device use in the prior 30 days
• individuals who have Type 1 or Type 2 Diabetes
• individuals who are pregnant