Did leave this as a comment on my original post yesterday but thought I'd just repost here as a new entry.
Hi All - a small update. After only completing week 1, run 1, my back has been TERRIBLE! For the first time in ages, I've had to resort to taking 2 co-codymol painkillers. I don't think even gentle jogging is going to do me any good. Most of my friends have shouted at me for being so silly for even thinking that I could jog with a bulging disc in my lumbar spine. The power walking has been good and my back even felt better! Hopefully, a few days rest is all I'll need to get back to where I started. I'm waiting to see a neuro-surgeon about my back, so until I've had my appointment, I think I'll stick to power walking. Good luck to you all on your own special journeys!