Personalized Half Marathon My 1st 13.1 Run Long Sleeve T-Shirt. Cute half marathon running Long Sleeve T-Shirt - Pink outfit says my 1st 13.1 run for girls. 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