Comfort that Goes the Distance. The Nitro Running Foot is a custom foot module engineered specifically for jogging and distance running. Each c-shaped running blade is handcrafted using our proprietary carbon fiber layering technique to provide the ideal amount of spring needed to run comfortably. The Nitro Running Foot is customized to user weight and running experience to provide the appropriate balance between strength and flexibility for high impact activities. A tall profile design is available for adult users while the short profile design requires less build height for petite users and children. A male pyramid attachment simplifies the fitting process.