ourparks.org.uk/couch-to-fitness
I just wanted to recommend this free fitness programme. I am highly unfit and obese but want to change that so signed up and have now finished week 2. It works like couch 25K in that you start slow and build up and they give easier versions for those of us who need to break in a bit slower.
Anyone looking for a guided exercise programme this one is worth a try. They do free outdoor group sessions too from what I can see but they seem to all be around the London area.