title: The effects of exercise intensity or drafting during swimming on subsequent cycling performance in triathletes.
abstract: 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 20 min cycle TT preceded by a 400 m 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 400 m 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.
authors.affiliation: Health and Exercise, School of Medical Science, University of NSW, Sydney, Australia. d.bentley@unsw.edu.au
authors.forename: David J
authors.initials: DJ
authors.lastname: Bentley
authors.forename: Sebastien
authors.initials: S
authors.lastname: Libicz
authors.forename: Aurelie
authors.initials: A
authors.lastname: Jougla
authors.forename: Olivier
authors.initials: O
authors.lastname: Coste
authors.forename: Jerome
authors.initials: J
authors.lastname: Manetta
authors.forename: Karim
authors.initials: K
authors.lastname: Chamari
authors.forename: Gregoire P
authors.initials: GP
authors.lastname: Millet
mesh_terms: D000328:Adult; D001642:Bicycling / Q000502:physiology*; D001696:Biomechanical Phenomena; D004734:Energy Metabolism / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D013550:Swimming / Q000502:physiology*; D013997:Time Factors
chemical_list: D019344:Lactic Acid