The purpose of this study was to determine the influence of factors such as sports consciousness, sports conditions and physical fitness to sports activity, and to examine the influence of sports consciousness and sports conditions on the improvement of physical fitness in adolescent male students. The Diagnostic Inventory for Sport Counseling (DISC) and physical fitness tests designed by the Ministry of Education in Japan were administered to 687 healthy male students aged 15 to 20 years. Six sports consciousness scales and 15 sports condition scales were conducted according to the procedure of DISC. Sports activity was defined as the frequency of sports participation per week. Students doing sports activity less than twice a month were termed as a negative or passive sports participation group (SG1) and those doing it several times or more a week were named as a positive sports participation group (SG2). Statistical techniques of discriminant analysis and multiple regression analysis were used to examine the contribution of variable groups to sports activity or physical fitness. The main results can be summarized as follows: 1) The SG2 have the higher sports consciousness and the better sports conditions, and the members are superior in physical fitness to those of SG1. 2) Sports conditions influence students' sports activity greater than sports consciousness and physical fitness level. In addition the present sports conditions is the most important factor influencing their sports activity. 3) Sports conditions in SG2 and sports consciousness in SG1 have a high influence on the improvement of physical fitness. Factors such as delight and anxious feeling to sports activity in sports consciousness, and sports skill, adaptability to personal relations and membership of sports club in junior high school in sports conditions contribute highly to the improvement of physical fitness.
