Effects of cycling alone or in a sheltered position on subsequent running performance during a triathlon.

Abstract

The purpose of this study was to compare the responses during a triathlon in which cycling was performed alone, as well as in a drafting position. Eight male triathletes of international level performed a sprint-distance triathlon (0.75-km swim, 20-km bike, 5-km run) on two different occasions, one completely alone (TA), the other as a drafter during the bike leg of the event (TD). The speed during drafted cycling remained at all times identical to the no-draft situation. The results revealed that expiratory flow (VE), oxygen uptake (VO2), heart rate (HR), and blood lactate concentrations ([La-]) were significantly lower when drafting on the bike as opposed to biking alone (112.1 vs. 162.2 L x min(-1), 55.2 vs. 64.2 mL x min(-1) x kg(-1), 155 vs. 166.8 beats x min(-1), and 4.0 vs. 8.4 mmol x L(-1), respectively). The results also showed that running after biking in a drafting situation (for similar bike speeds) significantly improved the running speed compared with that of the no-draft modality (17.8 vs. 17.1 km x h(-1)). Furthermore, VE, VO2, HR, and [La-] were significantly higher during TD run compared with TA run (161.6 vs. 141.4 L x min(-1), 70.9 vs. 67.1 mL x min(-1) x kg(-1), 175.3 vs. 167.98 beats x min(-1), and 8.1 vs. 7.6 mmol x L(-1), respectively). These results showed that drafting allows triathletes to save significantly on energy during the bike leg of a triathlon and creates the conditions for an improved running performance, with higher benefits for the strong runners.