Performance and drag during drafting swimming in highly trained triathletes.
OBJECTIVE
The influence of drafting was studied on the swimming performance, metabolic response, and passive drag of eight triathletes.


METHODS
The performance in drafting position was measured directly behind another swimmer during a 400-m swim and compared with the nondrafting position. Metabolic response concerned VO(2), blood lactate, stroke rate, stroke length, and rating of perceived exertion. Drag was measured by passive towing.


RESULTS
In drafting position, the triathletes swam on average faster (3.2%) over the 400-m swim than in nondrafting position (4 min, 47.69 +/- 10.35 s vs 4 min, 57.25 +/- 7.24 s; P < 0.01). Blood lactate and stroke rate were significantly lower (9.6 mM vs 10.8 mM; 39.9 cyclexmin(-1) vs 41.3 cyclexmin(-1) P < 0.02) and stroke length higher (2.10 mx cycle(-1) vs 1.97 mxcycle(-1), P < 0.01) than in nondrafting position. VO(2) and rating of perceived exertion were not statistically different. Passive drag was lower in drafting than in nondrafting position (P < 0.01). However, the gain in drag decreased with the towed velocity (from 26% at 1.1 mxs(-1) to 13% at 1.7mxs(-1)). In drafting position, the performance gain was related to the 400-m time (r = 0.80, P < 0.01) and to the skinfold thickness (r = 0.94, P < 0.01), with faster and leaner swimmers having greater gains of performance.


CONCLUSIONS
Swimming behind another swimmer in a race is advantageous for triathletes.
Laboratoire de Physiologie, GIP Exercice, Faculté de Médecine, Université de Saint-Etienne, France. chatard@univ-st-etienne.fr.
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Chatard
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Chollet
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Millet
D000328:Adult; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D010101:Oxygen Consumption; D012885:Skinfold Thickness; D013550:Swimming / Q000502:physiology*; D013647:Task Performance and Analysis
D019344:Lactic Acid