I have recently come off of a upper respiratory infection, so I have been off of running. I was told when I would be cleared to run, and I have tried to resume training. However, I still have a somewhat runny nose, so I haven t been running. However, I went for a run today, and after just around a minute, my chest started hurting, and I suddenly became out of breath. I had to stop and catch my breath before I could keep on, but I decided to walk back home instead of pushing something that might need healing. What is wrong?