I ordered the XL Navy shirt to workout in.  It fits loosely and is comfortable.  I hate working out in a t-shirt that fits snugly so this was exactly what I was looking for.  I was worried this would be too thin, but it is not.  The fabric is soft and drys quickly.  Great workout shirt, no complaints.

Just ordered another one of these, this time the Stealth color.  The picture online looked to me to be greenish.  The shirt I got is much more of a dark grey.