The purpose of this study was to compare the affects of drafting or a reduction of exercise intensity during swimming on the power output sustained (P mean ) during a subsequent cycle time trial (TT). In addition the relationship between peak power output (PPO) and P mean generated during the cycle TT after swimming was examined. Nine well-trained triathletes performed an incremental cycling test to exhaustion for determination of PPO. In addition, each subject performed three swim-cycle (SC) trials consisting of 20min cycle TT preceded by a 400m swimming trial completed as (1) “all out” and in a non-drafting situation (SC 100% ); (2) at 90% of SC 100% in a non-drafting situation (SC 90% ); (3) in a drafting position at the same controlled velocity as SC 100% (SC drafting ). Swimming velocity (ms −1 ) was significantly (p<0.01) lower at each time point during the 400m swimming trial in SC 90% compared with SC 100% and SC drafting . There was no significant difference in velocity between SC 100% and SC drafting . Blood lactate (BLA) concentration was also significantly (p<0.01) lower after swimming in SC 90% compared to SC 100% and SC drafting (3.8±0.9 versus 7.3±2.4 and 7.9±2.4mM). The Pmean was also significantly (p<0.05) lower in SC 100% relative to the SC 90% and SC drafting (226±15 versus 253±33 and 249±36W). There was no significant correlation between PPO (W) and P mean for SC 100% (r=−0.32), SC 90% (r=0.65; p=0.058) or SC drafting (r=0.54). This study indicates that drafting or swimming at a lower velocity did not induce any conflicting affects on power output during a subsequent cycle TT. However, this study confirms that P mean during a cycle TT is reduced when prior swimming is performed. Furthermore the positive relationship typically observed between PPO and P mean is disrupted by swimming activity performed before a cycling TT. This factor should be considered in terms of physiological analysis of triathletes.