I know I have the CS shelf too! Good luck! If it makes you feel better I was the lightest I have been in 5 years when Jake turned 1 - so it does move - and didn't go near a gym bcos I had a reflux baby and was in hell. Walking was my therapy and the hills were great - if you wear the baby in a pouch it also adds weight so you have more resistance. Oh and see if you have a friend who will help you do a big cook up to freeze for those lazy nights - they can baby wrangle or do the cooking.