I would like to raise money to remember a dear friend who died of cancer by joining a one day 26 mile walk along hadrians wall.im told it will be a tough steep walk. I'm a fattish 56 year old who averages 10,000 steps a day and am in reasonably good health. Am I taking on too much? Is there time to train to build up to this and what would you suggest I do to get fitter between now and then?