Pilates does more than kick your butt - it also tones the abs. People who do Pilates really do have abs of steel but it's REALLY hard work.

There are so many different kinds of yoga from Bikram (the hot sweaty kind) to Hatha or Baptiste (the quiet, meditative, slow and gentle kind) to Ashtanga or "power flow" (very aerobic). Try several different styles to see which one you feel most comfortable with.