Effect of tart cherry juice on recovery and next day performance in well-trained Water Polo players

A randomised repeated measures, cross-over design was utilised. All participants (n=9) were recruited from the Western Australian Institute of Sport (WAIS) Waterpolo (Men) Squad using the attached participant information sheets. A meeting was held with the head coach of WAIS Water Polo to discuss opportunities to disseminate the information sheet to potential participants. The information sheet was handed out at a training session. This information contained the lead investigators contact details, allowing potential participants to register their interest should they feel inclined. Each experimental trial occured over 7 days. From day 1 to day 6, participants were supplemented with tart cherry juice or a placebo equivalent. During experimental weeks, all training (technical skills, weights, swimming) and recovery activities (cold water immersion) will be identical (between the cherry juice and placebo groups) and undertaken in a controlled environment. All testing sessions will also be performed in the morning to minimise any diurnal influence. Water-based performance testing included numerous tests (10 m sprint, water polo multi stage shuttle test, in water vertical jump and repeat sprint test) performed at the start (day 1) and at the end of each experimental trial (day 7). Finally, a 5-week washout period was adopted between the two experimental trials to preclude any follow-on effects, On day 6, participants performed a simulated fatiguing team game activity, which has previously been reported to mimic the demands of a waterpolo match (Tan et al., 2010). The following morning (day 7), performance tests were repeated. Additionally, throughout the investigation various biological markers will also be measured (via venepuncture) to assess the efficacy of the cherry juice. Inflammatory markers (HS IL-6 and CRP) were measured on day 6 (pre- & post-exercise) and on day 7 (12 h post-exercise). Additionally, markers of oxidative stress (Uric Acid and F2-isoprostanes) were measured on day 1 and 6 (pre- & post-exercise), and again on day 7 (pre-exercise). Participants consumed 90 mL daily of tart Montmorency CJ (Prunus Cerasus) concentrate (Cherry Active, Sunbury, UK) or a placebo equivalent for a total of 6 days. The cherry concentrate was diluted with water, such that each 30 mL serving was made up into a 200 mL beverage. Both the cherry juice and placebo were consumed in two doses each day; 200 mL before morning training, and 400 mL in the evening post-training. According to the manufacturer, a 30 mL dose of Cherry Active concentrate is equivalent to approximately 90 whole Montmorency tart cherries (Cherry Active, Sunbury, UK) containing 9.117 mg/mL of anthocyanins, which can have positive health and performance outcomes (Bell et al., 2014, Bowtell et al., 2011, Howatson at el., 2012).Daily adherence to supplement consumption was made by the investigators being present at every training session and obtaining empty bottle containers. Bell, P.G., McHugh, M., Stevenson, E., & Howatson, G. (2014). The role of cherries in exercise and health. Scandinavian Journal of Medicine & Science in Sports, 24, 477-490. Bowtell, J., Sumners, D., Dyer, A., Fox, P., & Mileva, K. (2011). Montmorency cherry juice reduces muscle damage caused by intensive strength exercise. Medicine & Science in Sports & Exercise, 43, 1544-1551. Howatson, G., Bell, P.G., Tallent, J., Middleton, B., McHugh, M.P., & Ellis, J. (2012). Effect of tart cherry juice (prunus cerasus) on melatonin levels and enhanced sleep quality. European Journal of Nutrition, 51, 909-916. Tan, F., Polglaze, T., Cox, G., Dawson, B., Mujika, I., & Clark, S. (2010). Effects of induced alkalosis on simulated match performance in elite female water polo players. International Journal of Sport Nutrition, 20, 198.