The purpose of this study was to investigate the effects of difference in types of competitive swimwear on active drag and stroke performance. The subjects consist of four free style swimmers and four butterfly swimmers. The subjects wore four different types of competitive swimwear (full body swimwear : LJ, full length swimwear: FL, half length swimwear : SP, bikini type swimwear : C). The drags during swimming measured by using Active Drag System (Shimonagata et al., 1998) and the stroke performances were calculated by movie analysis. In this study, the maximal propulsive force was equal to the sum total of drags. About butterfly, the maximal propulsive force of FL was bigger than the other swimwear. And active drag of SP demonstrated advantage over LJ and C. Stroke length of FL were longer than the other swimwear, and stroke rate of FL were lower than LJ and SP. The velocity of FL affected by stroke length and stroke rate was fastest. These results showed that the types of swimwear affected the maximal propulsive force and active drag. In addition, it was suggested that the types of swimwear affected the stroke length and stroke rate.

DESCENTE SPORTS SCIENCE Vol.31/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE