Train hard. Recover hard. Repeat. Fast workouts DNA FLASH foam is nitrogen infused for an optimal combination of energy return and light weight that adapts to your unique stride and allows you to run fast DNA FLASH is engineered from ultra-lightweight materials so none of this weighs you down. Our cushioning technologies all start with DNA because they react to your unique stride. Quick recovery The combination of light weight, a responsive ride, and soft cushioning helps the shoe absorb impact during a hard workout — allowing you to quickly get back to the grind. Performance fit The breathable stretch-woven upper moves with your foot to provide maximum comfort. This helps keep your feet at a cool temperature even on hot days.