Sometimes I'm going to do 30 minutes on the elliptical and at about the 20 minute mark I start wanting to quit. At that point I start thinking to myself how I'm not going to feel good if I quit early or that I've already gone more than 1/2 way and if I can go that far, I can definitely finish. Just think about the calories you are burning and how its going to help you get to your goal. Good luck!