I was looking for a fitness short that I could fit my cell phone in comfortably, too, while on long bike rides and hikes. I am 5' 3", 125 pounds 30" waist, 35" hips, and am an ex-gymnast, muscular build. The medium fits well and the waistband is comfortable and doesn't leave elastic marks on the skin. I decided to try the large and the difference is that while it still rides up in the inner thigh, it is not to the degree which the medium do so. I would probably be best between a medium and largeSee full review