I own several of these tees in short and long sleeve. They run very snug, so I size up to an XL (I'm between a M and L in other Athleta tops). The problem with sizing up is the neck and shoulders become loose and wide, compared to the rest of the shirt. I wish Athleta offered a top like this in a... slightly more relaxed, but not loose fit. I really like the sticky band at the bottom for no ride-up when working out or running and the fabric is substantial for hiking or weight lifting. I also appreciate the subtle striping that is offered in a few colors. However, I always look a bit frumpy in the neck and shoulders due having to size up so much for it to fit my mom middle and the length is too long for my shorter frame. Head's up, the "willow" color is much more of a drab olive green than depicted in the photos. I had to send some of those back. Willow didn't look green at all in the photos.