I've never heard not to do push-ups, but many people with COPD can't do crunches because bending at the waist constricts the lungs too much and they really can't breathe. If you can do them comfortably at the time you do them, go right ahead. The only reason not to do them is that you may find it's too hard to breathe at all.

I don't think your being breathless one or two days after doing them has anything to do with push-ups or crunches. If you were going to have trouble because of them, you'd have it right then, not 24 - 48 hours later. That's something else entirely.

Thanks for the reply Jean. My heart is ok so it must b muscoskeletal thankfully. I have haemochromatosis as well and maybe its something to do with that also