Document Type



The purpose of this study was to determine change in relationship between stiffness of triceps surae muscle-tendon unit and race performance after one year with continuous training in well trained long distance runners. For 9 long distance runners, official race record and stiffness indexes of both muscle and tendon were investigated in pre and post measurements (after one year). The race performance (1.9%), passive torque of ankle joint (13.2%), and muscle stiffness index (73.6%) increased significantly between pre and post. Although significant correlations were not found between increment of race performance and change in all parameters, 6 of the 9 athletes showed increments of both race performance and stiffness index of muscle tissue. These results suggest that an increment of stiffness of the ankle joint and triceps muscle could be related to improvement of race performance in distance running.