Personalized Santa Hat Gym Text Gray Youth Long Sleeve T-Shirt. The word gym with the letter G in the word gym wearing a Santa hat is a funny Christmas gift design for exercise buffs, body builders, trainers, gymnasts and physical education teachers. youth long sleeve t-shirt. Shoulder-to-shoulder taping. Youth: S(6/8), M(10/12), L(14/16), XL(18/20)