I have several TSLA rash guards in the regular (not slim) fit. I. am 5'8"; 130 lbs and a size medium fits me perfectly. The length of the body and sleeves is generous. However, this thermal top is cut totally differently. The body and sleeve length is short, and overall, the size medium was way too tight for my liking. I love the fabric, though, and it appears to be a quality, well-made shirt.See full review