Hitting the gym for a high intensity class or hitting the track for intervals just got easier with the 361 Bio-Speed training shoe. This ultra-lightweight shoe gives athletes the advantage of natural movement and speed during their workouts. Bodyweight and aerobic style movements are enhanced with the streamlined fit and structure of the Bio-Speed. Upper: Lightly padded heel collar and an ultra-light tongue enhances comfort. Lace-up front offers an adjustable fit. Open weave mesh provides breathable flexibility. 3D overlays offer lightweight support. Midsole: Molded blend of QU!KFOAM™ for additional comfort and support. Carbon fiber shank for support and stability. Removable insole. Outsole: High abrasion rubber placed in the heel strike zone. Lighter weight blown rubber in the forefoot provides enhanced shock dispersion and traction.