TOUSSAINT, H. M., L. BRUININK, R. COSTER, M. DE LOOZE, B. VAN ROSSEM, R. VAN VEENEN, and G. DE GROOT. Effect of a triathlon wet suit on drag during swimming. Med. Sci. Sports Exerc., Vol. 21, No. 3, pp. 325–328, 1989. The effect of a triathlon wet suit on drag was studied in 12 subjects (eight male, four female) swimming at different velocities (1.10, 1.25 and 1.50 m·s-1). The active drag force was directly measured during front crawl swimming using a system of underwater push off pads instrumented with a force transducer (M.A.D. system: 6). Measurements were made when swimming over the system with and without a wet suit. A 14% reduction in drag (from 48.7 to 41.8 Newtons) is found at a swimming velocity of 1.25 m·s-1, which is a typical swimming speed for triathlon distances. At 1.50 m·s-1 a reduction in drag of 12% was observed, which suggests that the wearing of such a suit might be beneficial in conventional swimming events. The reduction in drag can explain the higher swimming velocities observed in triathletes using a wet suit. The effect of the reduction is probably largely due to an increased buoyancy inducing less frontal resistance. However, since the effect of the suit on the lighter female swimmers was not different from the effect on the heavier male swimmers, a reduction in friction drag and drag coefficient may also be significant.