Positive swim pacing improves sprint triathlon performance in trained athletes

Background: Triathlon is a multi-sport event that consists of sequential swim, cycle and run disciplines. The manipulation of pacing during triathlon is crucial to performance but complex due to the importance of optimising energy expenditure throughout the three different locomotion modes. Although the effect of pacing during cycling on subsequent running performance is well documented, the majority of these studies lack an initial swim discipline, which may inaccurately reflect the metabolic demands and pacing strategies adopted during a triathlon. The purpose of this study was to investigate the effect of three swim pacing strategies on subsequent performance during a sprint distance triathlon (SDT).

Methods: Nine well-trained male triathletes completed five experimental sessions, including a graded running exhaustion test, a 750 m swim time-trial (STT), and three SDTs. The swim time of the SDTs were matched, but pacing was manipulated to be either positive (i.e. speed gradually decreasing from 92 to 73% STT), negative (i.e. speed gradually increasing from 73 to 92% STT) or even (constant 82.5% STT). The remaining disciplines were completed at a self-selected maximal pace. Speed over the entire triathlon, power output during the cycle discipline, rating of perceived exertion (RPE) for each discipline and heart rate during the cycle and run were determined.

Results: Faster cycle and overall triathlon times were achieved with positive swim pacing (30.5 ± 1.8 and 65.9 ± 4.0 min respectively), as compared with the even (31.4 ± 1.0 and 67.7 ± 3.9 min respectively) and negative (31.8 ± 1.6 and 67.3 ± 3.7 min respectively) pacing strategies. Positive swim pacing elicited a lower RPE (9 ± 2) than negative swim pacing (11 ± 2). No differences were observed in the other measured variables.

Discussion: This study demonstrated superior cycle and subsequently overall performance during a sprint distance triathlon when adopting a positive swim pacing strategy, as compared with negative and even swim pacing strategies. Despite a matched swim time, a higher cycling power output was elicited after the positive pacing swim during the earlier stages of the cycle discipline, compared with the negative and even pacing strategies. This could be due to a lower sense of fatigue following the positively paced swim as indicated by the lower rating of perceived exertion.