I would suggest doing crunches throughout the day and cardio, and maybe some running, too. When I go to the gym, I do the elliptical and do always a mile on the tread mil, if i really want to push myself i will do 2 miles. I try not to do so much because I do a good 3 miles on the elliptical. Altogether, I burn a almost over 400 calories. Crunches is your best bet though, you have to do them religiously. Also, running doesnt burn as many calories as you think....just thought i would add that because i noticed someone say run.