Interesting. I can't even wear a men's small nor extra-small. A man's very small size is still usually too big for me. Usually in the body side cut, length of sleeves.

About 10 yeas ago, I have bought and worn happily 2 men's dress small shirts (collar size, 15 inches)...out of desperation when I was cycling for 3 weeks in summer in sunny 35 degree (or 85+ F degree) weather. Bought used shirts at a local Salvation Army outlet on 3rd day of trip and wore them with rolled long sleeves...to protect my arms that already had lst degree sunburns.

I wore 1 of the men's dress shirts (white) for the next 10 years, whenever I went cycling for several hrs. on sunny summer days. Even wore it in Hawaii with a funny Hawaiian skort. Really, I have never worn aerobic/cropped fitness tank tops. I want to PRESERVE the smoothness of back and arm skin...away from sun.

Otherwise, occasionally will haunt teenage boys section. I know, a 48 yr. old woman wandering around there.. Tends be for sportswear/fitness wear -ie. loose hiking pants, fleecy jacket, etc. Part of the problem is teenage boys' wear still not cut for even small curves found a woman like myself.