FLEXIBLE STABILITY The Nike Free TR 6 Women's Training Shoe delivers the flexibility and stability your workout demands with an innovative outsole pattern that expands, flexes and contracts with your foot during every squat and sprint. Flexible, Stable FoundationThe tri-star outsole pattern expands and contracts in every direction, with your every step, to disperse pressure evenly and enhance flexibility and stability. Rubber pods wrap up the side of the shoe for even more stability and traction. Dynamic LockdownSuper-strong, ultralight Flywire cables hug your foot for dynamic support, loosening and tightening with your foot's natural motion. Targeted VentilationThe engineered mesh has open areas for ventilation and closed areas for the support you need as you train. More Details • Breathable mesh lining in the forefoot • Molded ankle foam enhances support and fit • Outrigger for stability during side-to-side movements • Injected foam midsole/outsole for ultralight comfort Nike Free OriginsAfter learning that Stanford athletes had been training barefoot on the university's golf course, three of Nike's most innovative and creative employees set out to develop a shoe that felt natural and weightless, similar to bare feet. The team spent eight years studying the biomechanics of runners' feet in motion. The results yielded a profound understanding of the foot's natural landing angle, pressure and toe position, allowing Nike designers to build an unconventional and flexible running shoe from the inside out.