This study investigated the effects of kendo practice on changes in urinary volume, creatinine, sodium ion (Na+), and chloride ion (Cl-), and in blood lactate. Six healthy male kendo club members performed three typical kendo practices-5 min Jigeiko,5 min Kakarigeiko, and 5min Kirikaeshi with their maximal effortor a continued warming-up exercise (control). Urine was collected 5 times after each type of exercise: after 30 min rest in a sitting position following urination, after 30 min warming-up exercise, and after 30,60, and 90 min of recovery from exercise. Blood samples were collected twice: during the resting period and at 5 min after exercise. The urine taken 30 mmn. after the end of exercise, which most distinctively showed effects of practice, was compared between practices. Urinary volume, Na+, and Na+/Cl- were significantly higher after Kakarigeiko than after Jigeiko and Kirikaeshi. Urinary creatinine concentration was significantly lower after Kakarigeiko than after Jigeiko and Kirikaeshi. The post-exercise blood concentration of lactate was significantly higher after Kakarigeiko than after Jigeiko and Kirikaeshi. Thus, urinary excretion after Kakarigeiko, in particular, showed specific changes. The possible reason is that Kakarigeiko is accompanied by heavy lactate oxygen debt, which might depress the function of kidney tubules, resulting in loss of reabsorptive function in response to glomerular filtration rate.
