So for awhile I was doing a lot of spin classes, because I figured it would be a quick and efficient way to get my aerobic workout in. THEN, my thighs started to get bigger, even though when I took spin, I put the bike on virtually NO RESISTANCE. I started working out for a trainer, and he told me that women with curves, or 'hourglass' shapes, should stay away from spinning, because it will just beef up your thighs. The best thing? Elliptical with little or no resistance.
Also to stay away from for curvy girls: Kick boxing, walking or jogging on an incline. Having that info has made all the difference!
How frustrating that must have been! I remember when I was lifting weights to try and burn off the fat on my arms. Whoops. It resulted in me building muscle that, when I stopped, turned right into fat. FRUSTRATING!