Personalized I Think Therefore I Run Long Sleeve T-Shirt. I Think Therefore I Run! Those who think use their brains and make a difference in the world, and those who run make a difference in themselves! Great gift for your favorite deep thinker and athlete. Pre-shrunk 100% cotton 6.1 ounce long sleeve t-shirt. Double-needle stitched neckline and sleeves. Quarter turned. Shoulder-to-shoulder taping. Adult: S, M, L, XL, 2XL, 3XL