PCS Mikey,

It sounds like you are in the same boat as me, its already frustrating as I used to go the gym two or three times a week. I can walk a fair distance now, about a mile, but I may or may not get symptoms. I couldn't have managed this three weeks ago. As soon as I feel pressure I stop, as I now know the consequences. Its all about doing the things that suit you best, I might try 3 mins on a stationary bike, I did five minutes on a crosstrainer and that made me ill. Take it steady and good luck to you!