Researchers found that increased shoe longitudinal bending stiffness improves the running performance and the running economy [1]. But there still remain questions how the stiffened shoe help runners reduces the energy expenditure and how to obtain or predict the optimal shoe bending stiffness for running economy by individual. Previous researches suggested that flexed shoe and its elastic energy might help runner reduces his work [3], but excessively stiff shoe might have the worsened working condition of muscle-tendon system [4]. In this research, we hypothesized that maximizing the reutilization of elastic energy stored in elastic insole and minimizing the disturbed or restricted joint movements with excessively stiff insole would improve running economy.