What struck me was the unique look of the shirts thanks to the colors and graphics. I love the shirt and wear it for light workouts. I didn't know what size to order but I went for a small one. I'm somewhere between small and medium. I'm 5-9 years old, skinny with a 37 inch chest. The little one isn't exactly tight, but definitely not loose. I still wear it comfortably, but I might order a medium just to compare and wear while running in the summer heat.