This shirt works great for an athletic build but if you are medium fat I would either go up a size or throw it away. I wouldn't say it runs small because it's not a fitted shirt, just bear that in mind when ordering.
H2H Mens Casual Slim Fit Short Sleeve T-Shirts Cotton Blended Soft Lightweight V-Neck/Crew-Neck
46 Review
Calvin Klein π Herringbone Sleeve Men's Dress Clothing
50 Review
Men'S Long Sleeve Polo Shirt - Slim Fit, Stretchy, Breathable Collar
43 Review
Van Heusen Traveler Stretch Men's Shirt
47 Review