The purpose of the study was to investigate the influence of short-term weight loss on body shape, physical fitness, and blood variables in college ssireum (one of the Korean traditional martial art) athletes. Six college ssireum athletes participated as subjects. The weight loss program includes 50% of limited diet, 5.5 hr of physical and skill training. Body composition such as weight, body fat, muscle mass, and body mass index (BMI) was determined. Fitness test such as shuttle run, sit-up, trunk extension test, grip test, sitting reach test, and side step test was measured. Blood variables such as total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein, glucose, reactive oxygen species (ROS), malondialdehyde (MDA), and superoxide dismutase (SOD) were checked before and after the short-term weight reduction. The results revealed significant decrease in body composition such as weight, body fat, muscle mass, and BMI. Fitness test also showed significant decrease in sit-up, trunk extension test, and grip test. The results demonstrated positive significant change in side step test, shuttle run, and sitting reach test. The results of blood variables showed significant decrease in total cholesterol, LDL, glucose and SOD. In contrast, MDA revealed significant increase and no significant change was found in ROS. Finally, it is assumed that a proposal of weight loss without decrease of muscle mass, muscle force, and muscle endurance is necessary because of the negative effects on muscle force and muscle endurance which should be used during actual games.