ABSTRACT
For the purpose of examining relative impact of the middle-distance triathlon race (Swim : 2.0 km, Bike : 90.0 km, Run : 21.0 km), blood samples were taken on the day before, immediately after, and the day following the race from triathletes who participated in a middle-distance triathlon race at Tokunoshima, Kagoshima in June 1993. White blood cell count was significantly increased immediately after the race.It was recovered on the next day to the value observed before the race. Serum creatine phosphokinase activity was elevated significantly immediately after the competition. It continued to rise up to the level of about 4 times higher than the pre-race value. In terms of renal function, serum creatinine concentration showed a significant increase immediately after the competition. However, it recovered to normal range by the day after the competition. In addition, serum urea nitrogen concentration was also significantly increased after the competition. It remained at the high level until the day after the competition. In conclusion, it might be suggested that the middle-distance triathlon gives a significant impact on human body, even though it is quntitatively less than the long-distance type (Swim : 3.9 km, Bike : 180.2 km, Run : 42.2 km) .