Running for me comes with two physical feelings. The first is that burning of the legs. I am learning to move past that and eventually it does lessen. The next feeling is horrific. Remember that scene in Alien when the creature burts out of the chest. You know the one I am talking about. That is the exact feeling I get. I know that despite the pain it means that my heart and lungs are getting stronger.
I have been working at walking for 5 minutes, run for 90 seconds, walk for 2 minutes and repeat 6 times. I decided to go for endurance instead of speed. I know this means less of the alien feeling meaning less cardio work-out but I needed to boost to my self-esteem. I ran longer than the 90 seconds and for the last rep I ran for all my might. That familiar, horrific alien bursting feeling came back. It had not left me. But, I will take comfort in the fact that it means my heart and lungs are getting stronger. I will not die from the alien feeling. I can actually do this.