I have been biking with a group of people a few days a week. I ride a modest 25 miles a week just yet. I have a Townie cruiser bike as i cant ride a rode or mountain bike its hurts my bike. I have been doing 75 situps a night as well. I am 5'2 and weigh approx 118. Recently i noticed my jeans are tighter around my thighs and butt! and its making me frustrated, as i think fat. But people around me have saidi look fit. Now is this because im building muscle under fat? Or because I am just building muscle so my body now does not squish into tight jeans anymore. Im feeling a little confused, I thought I would slim down.