"A typical London commuter takes 3,400 steps, walks more than two miles and uses up 246 calories each day on the journey to and from work". Over a five day week that's apparently the equivalent of an hour's jogging or burning off two Big Mac meals.
The survey looked at three typical rail commutes but also added short Tube journeys at the end of them. This meant three sets of steps, at least one escalator (did they count walking up the escalator though?) and an eight minute walk from the Underground to work.
They got in a a fitness expert to try to verify their theory, who rather obviously said "Commuters tend to walk at a much faster pace, have stairs and escalators to overcome and often have to run to catch trains so the heart rate increases and calories are burned." Peter Hood continued "Depending on body weight, commuters could be shifting up to half a pound of body fat in oune week on the journey to or from work".
I suppose if you add sweating like a pig in over crowded carriages in the summer time, dealing with the numerous escalator closures so that you have to hike up the stairs and calories lost by the chocolate machines having a melt down, which should be thanking the London Underground for providing such a health conscious service!