The Men's Nike Free Trainer 5.0 Training Shoes Black/Wolf Grey offers an adaptive, supportive fit and lightweight flexibility for comfort and natural movement during intense training sessions.LIGHTWEIGHT FLEXIBILITY FOR INTENSE WORKOUTSFlexibilityHexagonal flex grooves in the outsole allow your foot to move naturally for improved agility and exceptional range of motion.Better ControlThe anatomically shaped heel is rounded to roll with the ground, promoting greater control to help you stay fast on your feet.Adaptive FitThe Dynamic Fit system is anchored under the midfoot and adjustable through the laces for customized lockdown and a secure fit so you can focus on your workout, not on your feet.More Benefits Breathable mesh upper for comfort Full-length inner sleeve for support and comfort Phylite midsole for lightweight cushioning that's tough enough to double as an outsole, dramatically reducing overall weightNike 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. In 2002, they examined a group of men and women with pressure-measuring insoles taped to their feet, using high-speed cameras to capture images of each foot in motion.The team spent eight years studying the biomechanics of shoeless running. 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....The Nike Training more colors