The Nike Free TR 5 Flyknit Women’s Training Shoe ups the ante with a new, lightweight Flyknit upper that adapts to the shape of your foot, offering a locked-down feel for cardio, strength training and other gym workouts that demand flexibility and support. Lightweight Flyknit The Flyknit upper hugs your foot with a sock-like fit for incredible lightweight support. Breathable areas are seamlessly integrated in the Flyknit to provide cool comfort during your workout. Natural Flexibility Hexagonal flex grooves are hot-knife cut into the midsole to create flex points that allow your foot to move more naturally than ever before. Supportive Fit Moulded foam lines the heel collar for a comfortable fit that helps lock your heel in place, and Flywire cables integrate with the laces to help stabilise your foot during agility training and cardio classes. More Benefits Moulded, stretchy partial inner bootie wraps up the heel for a comfortable, personalised fit Rubber pods on the sides of the shoe provide enhanced traction and stability for activities like side planks Strategically placed rubber on the heel and toe for added durability in high-wear areas Foam midsole for lightweight cushioning 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. 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.