Adult medium are a bit small so I would order next size up.
I already had two of your United States swimming sweatshirts and I really loved the color choice of the tank so I bought it. I love the material of the tank it's super soft and comfy even after washing. It fits true to size too which is always a worry when ordering offline.
United States Swimming Lace Hoodie
Love both tanks: USA Swimming and Just keep swimming. Great quality and both fit perfect.