The fabric is lightweight. I like the fact the back is longer than the front, covering more of your okole. And there are tiny “pukas” on the lower back to allow for some enhanced air circulation. I am about 5’3” and weigh around 97 pounds. I ordered an XS. The armholes are pretty large but I wear jog bras so the tops work out fine. An XXS might have fit better though. BTW, I was a runner but as I aged, I walk daily
