FLEXIBLE AND DYNAMIC The Nike Free Train Force Flyknit Men's Training Shoe is as dynamic as your workout, combining the second-skin fit of Nike Flyknit with a revolutionary Nike Free outsole that expands and contracts with your foot on every landing. Sock-Like Fit A Flyknit upper hugs your foot for a locked-in feel and lightweight, breathable support that moves with you during your workout. Stable Cushioning The shoe's unique dual-density midsole provides the cushioning you need for varied cardio workouts along with the stability required for lifting. Dynamic Movement With each stride, the updated Nike Free outsole's unique tri-star structure expands and contracts in all directions, following the natural motion of your foot. More DetailsFlywire cables offers support and lockdown during lateral movementsA mid-rise collar hugs your foot and ankle for a seamless fitHeel counter adds stability during quick cutsFirm heel helps you maintain your form during squatsWide forefoot allows toe splay when during liftingRubber reinforcement on the outsole adds traction and stability Nike Free Origins After 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. Flyknit OriginsNike Flyknit technology was inspired by feedback from runners seeking a shoe with the snug (and virtually unnoticed) fit of a sock. Nike embarked on a four-year mission with teams of programmers, engineers and designers to create the technology needed to make the knit upper with static properties for structure and durability. Then the precise placement of support, flexibility and breathability—all in one layer—was refined. The result is a featherweight, formfitting and virtually seamless upper.