I don't know if you have use of an elliptical, but no matter how in shape I think I am, all I have to do is hop on an elliptical and get a rude awakening about how awful my cardiovascular becomes over the winter months.

There is also a little plastic gadget you can get that helps to strengthen your lungs. I'm not talking about the sports kind they sell, not sure about those, but my husband has one his oncologist gave him when he was in the hospital and it actually helped my husband. It has a plastic tube hooked to a container that has a plastic ball in it. You gauge how well you do by the rise of the ball.