Up the tempo in our lightest and most responsive running shoe yet. The new Liberate Nitro is an ultra-fast option for short-distance runs and sprints, up to half-marathons. The simple mono-mesh upper is super-light and moisture-draining, so nothing can weigh you down, come rain or shine. A PUMAGRIP outsole and NITRO FOAM midsole add traction and cushioning to this high-tech shoe.. NITRO FOAM: PUMA's advanced technology providing superior responsiveness and cushioning in a lightweight package. PUMAGRIP: PUMA's durable rubber compound that provides all-surface traction. Low boot. Ultra-lightweight mono-mesh upper. NITRO FOAM midsole. PUMAGRIP rubber outsole for durability and traction. TPU heel piece for visibility and stability. Reflective branding and spoiler for increased visibility. Striped PUMA Formstrip at lateral side. PUMA Wordmark at heel.