Posted: 16/01/2015 at 15:31
I had pneumonia just under two years ago. I actually tried to run Brighton marathon with it (didn't know I had it at that stage.)
It took me approx 5 weeks until I felt up to running again and probably a couple of months before I felt I was back to where I was before. It wasn't the easy runs that were the issue it was the faster stuff that took a while to come back.
As RicF says take it very easy for a few weeks and build up slowly.