There was an interesting article in the London Evening Standard yesterday entitled "Walk the the tube with a step-by-step map". It reported the findings of a study organised by the health insurer PruHealth to establish how far apart in terms of steps are central London tube stations. Volunteers armed with pedometers recorded the number of steps they took and averages have been recorded on a tube map.
The message of course was that walking instead of taking the tube - or getting off a stop early - is an excellent way to help meet the recommended 10,000 steps a day target. And if you don't have a pedometer, forget it or don't want to wear it one day, you can still know how many steps you have taken.
Standard readers posted many supportive comments, although one or two wags noted that walking the tube was potentially hazardous as there might be trains on the lines.
The original map is on PruHealth's website (in the press releases section).