I purchased these pants for running. Buying shoes and clothes online is always a risk as you never really know if they will work out unless you already own the item. I got very lucky this time. I am 5'3" tall and weigh in at about 106. I got the small. They fit snug but not tight. After I washed them I had to shorten them two inches. This is typical for me but I would rather shorten a pair of pants then buy a 'short' or petite and have them too short. They are comfortable, smooth fitting - no bunching, and they look nice. The fabric is mid-weight 88% cotton, 12% spandex according to the label. I intend to purchase another pair.