ACTIVCHILL GRAPHIC ATHLETE T-SHIRT. A PERFORMANCE TEE WITH COOLING FABRIC. Let your soundtrack set the pace. This men's Reebok training t-shirt is built for HIIT workouts, heavy days and body-weight circuits in the park. Cooling Activchill is placed where you need it most, and the high-stretch fit moves with you through your full range of motion. Fresh air cycles through the mesh back panel to help you stay dry through the peak of your workout. Throwback graphics declare your Reebok pride.