Re: Exercise and breast feeding. Also pain in breasts
Excersize is fine while breastfeeding. The one thing to be cautious about is your bra, since poorly fitted bras can cause plugged ducts or reductions in supply. So make sure you have one that is properly sized, and avoid bras that hold you in place by compression.
I don't know about Zumba, but lots of moms here do or have done the 30 Day Shred, and there are even some threads going about it.
Sharp, quick, twinges of pain are probably nothing to be concerned about. It could just be the sensation you get as your breasts refill. However, if the pain increases or starts to turn into a burning pain, it's time to start thinking about nasty things like plugged ducts, mastitis, or thrush.
Coolest thing my big girl said recently: "How can you tell the world is moving when you are standing on it?"
Coolest thing my little girl sang recently: "I love dat one-two pupples!"