Personalized Heart Belongs To Gym Youth T-Shirt. My heart belongs to gym text with the word GYM wearing sneakers is a funny school design to brighten the day of teachers, students, athletes and fitness gurus. Let the good times roll in a durable T-Shirt that takes kids from school to play in an amazing array of colors. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar.