f you mated a training shoe with a racing shoe, this is what you’d get. The TR, or Trainer-Racer, is designed for runners who need a very light and flexible trainer. It’s also a good choice for larger runners who want to race in something lighter than they train in but who still need more support and protection than a racing flat provides. The upper is usually made with 1.5 mm Clarino® synthetic suede and 200 denier nylon mesh. Fully slip-lasted, the TR has our four-piece horseshoe midsole and a blown carbon rubber outersole.