Light speeds ahead. The Kinvara 12 is trusted go-fast trainer, further refined to make the most of less. Made lighter with a simplified upper, the ride feels as fast as ever—with the flex needed to get you to the start line stronger and the finish line sooner. PWRRUN cushioning maintains the lightweight responsiveness that makes this shoe a favorite for daily training miles or racing longer distances. The addition of more ground contact adds power to the flexible ride, making the transition from landing to takeoff even faster.; Lightweight printing gives just enough structure to the breathable, adaptable mesh upper to feel secure without weighing you down.