If you're like me, you probably grew up with the "normal" small, medium and large options for t-shirts. Now a days, you have different types of workout shirts that fit different body types and different tastes in fit. All in all, this ends up being very confusing when trying to buy the one size in the type that fits you just right, especially online, without the ability to try them on. Basically you end up feeling like Goldilocks, only with shirts. Unfortunately, a lot of these listings don't list what dimensions the sizes fit, and that adds to the confusion. For a point of reference, I am currently 5'6", 170lbs with a 42" chest and 32" waist (I could lie and give you the weight on my drivers license, but that wouldn't help you). So not in great shape, but not in horrible shape, either. I've found that I usually fit a medium shirt in the old school "S, M, L" sizing category, and the same seems to be true for my preference in size for "Fitted" shirts, such as this. It is a little snug, but not tight, which is what I am comfortable with when working out. I've found that for "Compression" fit shirts, I can get a large, and I still feel like an over stuffed sausage, and a medium there is just ridiculous.
As far as this particular shirt goes, I'm happy with the fit, quality and construction, and material. I usually prefer a polyester blend for workout clothes, since they tend to be more moisture wicking than anything with cotton in the mix, and this seems to follow that rule. If you're in awesome shape and can pull off going the compression fit route, I'm envious of you. For those of us who try to make it to the gym on a regular basis, fitted is the way to go. If you're just getting back after taking a workout leave of absence, regular or loose fit won't do you wrong. With whatever fit you end up going with, climalite will help keep you dry (and definitely more comfortable than a normal cotton shirt) during your workout. I think that's worth 5 stars.