My third pregnancy was twins. They slept, but at different times. They had a 25-minute overlap, and I would use something like Karen Voight's Yoga Stretch or one of my "parts" tapes. My babies needed to be held- all the time
so it wasn't an option to let them watch me while I worked out.
I walked my kindergartener to school when it wasn't snowing, but what really took the weight off was nursing. I was under my pre-pregnancy weight by the time they were 10 months old.
I agree that you should enjoy the special bonding time with your little one, but it's also important to do "strategic" exercises, especially for your abs and back. Those people get bigger, and yet they still demand to be picked up
Deb