This study was conducted to obtain basic data for successful conditioning before matches of sports with weight restrictions and for formulating an adequate dietary habit as a background of the athletic life.
　The subjects were 24 university judo team members (16 males and 8 females) who were making weight by discretionary methods in expectation of weight-class matches. The diet and the physical condition during this period were recorded, and the physical performance and the hematological profile during the weight-control period (the day before the matches) were compared with those in the weight-control-free period among three groups with different degrees of weight loss (no weight loss, weight loss< 6%, weight loss≧ 6%), to evaluate the effects of weight losses on the body.
　Physical performance and hematological profile : Little negative effects were observed when the weight loss was 2.8 ~ 8.5%, but the muscle strength (especially back muscles) was markedly reduced when the weight loss exceeded 10% of the initial body weight. Concerning the hematological profile, Al-P, LDH, and urea nitrogen showed significant increases, which were considered to be greater than the increase ascribed to blood condensation due to restriction of water intake and perespiration. Amylase, triglycerides, total cholesterol, and HDL-cholesterol showed significant decreases. These changes were more notable as the weight loss was greater. Significant decreases in WBC were observed also in the group with smaller weight losses.
　Diet and physical condition : According to the records of meals and the physical condition during the 23 days prior to the matches, the intakes of not only energy but also other essential nutrients including protein became more markedly reduced, and the self-evaluation of the physical condition tended to be more notably deteriorated as the matches approached in the subjects who lost more weight. Moreover, considerable inadequacies in the diet were evident from the dietary records even without precise nutritional evaluation also in those who did not need to make weight or during the period when the subjects were not making weight.
　These findings suggest 1) that the weight control before matches of weigh-class sports has less effects on the body as the weight loss is smaller, 2) that, to reduce the extent of weight control, establishment of a dietary habit adequate for the active life-style of athletes is urgently needed, and 3) that there are problems of weight control with the minimum effects on the body and dietary and nutritional management for this purpose.

DESCENTE SPORTS SCIENCE Vol.14/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE