Supplementation with a polyphenol supplement has been shown to reduce inflammation, oxidative stress, skeletal muscle damage, and improve isometric strength 24 hours after exhaustive and fatiguing exercise protocols. However, previous studies have not examined the effects on exercise performance within a simulated performance setting. The aim of the present study was to investigate the effects of Cherry Active (CA), a drink containing polyphenol compounds, on markers of oxidative stress and exercise performance in trained cyclists. Eight trained male cyclists (29.1 ± 5.3 yrs) were assigned to an experimental condition (30mls of CA), or a placebo (PLA) condition, in a counterbalanced fashion, with a 10 day washout period between trials. Drinks were consumed twice a day for 8 days and within 60 minutes of the time-trial (TT). Participants undertook a strenuous cycling bout, consisting of 25 minutes at 60%Wmax , 40 minutes at 80%Wmax , and 95%Wmax until voluntary fatigue (visit 2). This was followed 24h later by a simulated 30 minute cycling TT (visit 3). Blood samples were obtained in all visits; before, during, and after exercise; to identify changes in oxidative stress markers. A repeated measures ANOVA was used to determine significnat differences between conditons, all values are means ± standard error. Markers of oxidative stress malonaldialdehyde (MDA), protein carbonyls (PC), or total antioxidant capacity (ferric reducing ability of plasma (FRAP)) were not different between the CA and PLA groups. FRAP increased in response to exercise during both trials (Pre visit 2: 508µM ± 18 to Post visit 2: 613µM ± 21, p < .05; Pre visit 3: 552µM ± 14 to Post visit 3: 603µM ± 22, p > .05). MDA showed a small increase over the two trials (Pre visit 2: 10.4µM ± .56 to Fatigue at 95%Wmax 11.4µM ± .47, p > .05; Pre visit 3: 9.9µM ± .52 to Post visit 3: 11.7µM ± .86, p > .05) and there was a tendency for PC to decrease during the TT (Pre visit 3: 1.3 nm/mg ± .14 to Post visit 3: 1.1nm/mg ± .12, p > .05).TT finishing time was not different between CA and PLA (CA: 1605 secs ± 111; PLA: 1609 secs ± 115) nor was power output (CA: 292W ± 34.8; PLA: 292W ± 40.1). These findings indicate 8 days of CA supplementation did not attenuate oxidative stress, nor augment antioxidant defences in trained cyclists compared to PLA. Furthermore, CA did not enhance recovery 24 hours after completing a strenuous cycling protocol or provide an ergogenic effect in a cycling TT performance.