This study investigated the effects of acute alcohol consumption, in a natural setting, on exercise performance in the 2 days after the drinking episode. Additionally, alcohol related behaviours of this group of rugby players were identified. Prospective cohort study. Nineteen male club rugby players volunteered for this study. Measures of counter movement jump, maximal lower body strength, repeated sprint ability and hydration were made 2 days before and in the 2 days following heavy episodic alcohol consumption. Participants completed a questionnaire at each time point so that alcohol consumption and sleep hours from the previous 24 h period could be quantified. Additionally, participants completed the Alcohol Use Disorders Test (AUDIT) prior to completing baseline measures of performance. Reported alcohol consumption ranged from 6 to >20 standard drinks (mean category scale score=11-19 standard drinks). A significant decrease in sleep hours (p=0.01) was reported after the drinking episode with participants reporting 1-3 h for the night. A significant reduction (-1.8±1.5 cm) in counter movement jump (p<0.01) the morning after the drinking episode was observed; no other measures were altered at any time point compared to baseline (p>0.05). AUDIT scores for this group (18.2±4.3) indicate regular alcohol consumption at a hazardous level. Heavy episodic alcohol use, and associated reduced sleep hours, results in a reduction in lower body power output but not other measures of anaerobic performance the morning after a drinking session. Full recovery from this behaviour is achieved by 2 days post drinking episode.