Abstract
We studied changes in physical characteristics: body composition; muscle and physical strength; hematological parameters; and nutrients and food intake in 22 male college judoists who were losing weight purposefully. Nutritional parameters in blood, such as triglycerides, decreased immediately before matches and rebounded after matches. Free fatty acid increased before matches and returned to previous levels 10 days after matches. IgM and complements decreased before matches and did not return to previous levels even 10 days after matches. These changes were noted in the marked weight reduction group (weight lost / body weight before weight reduction, weight reduction rate≥6%). In contrast, creatine kinase increased before matches in the slight and moderate weight reduction groups (weight reduction rate< 3%, 3≤and<6%, respectively). The marked weight reduction group showed no changes in creatine kinase, however, indicating inadequate exercise due to excessive weight reduction. Muscle strength (grip) and nutrients and food intake decreased significantly before matches. These changes were noted in the marked weight reduction group. These findings suggested that a weight reduction rate of 6% or more adversely affected the performance and health of the judoist.