I recently hit 120 lbs, but it doesn't seem like I should weigh this much. I'm a runner and have an athletic build (smaller boobs/butt and larger thighs) I wear a size 0 or 25 in pants and I'm 5'4. I was wondering if it seems strange to anyone else that I would weigh this much. I'm not incredibly muscular and I have very little fat on my body.
Muscle weighs more than fat hun. Like you said, you have a muscular body so that makes you in better shape than a strictly skinny girl your height. A girl your same size but with no muscle definition would weigh less, that's true but they'd also be in worse shape.