After having a night out on Thursday I came to a situation where I couldn't walk home and my wife had to go and get the car. My legs felt totally exhausted, slight knee pains. It's never happened to me before, usually I walk very slowly with plenty of rests but this time I totally conked out. Has anyone else experienced this? I'll try to see my GP asap. Just wondering if it's part of the course. I suffer with heart failure and emphysema .