Abstract des Autors

Purpose: 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 VO2, 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 cycle/min vs 41.3 cycle/min, P<0.02) and stroke length higher (2.10 m/cycle vs 1.97 m/cycle, P<0.01) than in nondrafting position. VO2 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 m/s to 13% at 1.7 m/s). 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. Verf.-Referat