What type of fitness training will be the best?

[T-oddity]

I knew of some one in the military who had a saying, he did not want greyhounds, he wanted mountain goats, in other words the the fittest and fastest didnt survive, he wanted sloggers who were physically and mental strong enough to just keep going who would keep going regardless of the load or the conditions.
As far as I'm concerned keeping fit has to be part of your life style something that you do everyday and not something that you have to plan to do, i.e. cycle to work, hand sawing logs instead of using a chain saw, walk to the shops rather than use the car.
My main tip would be always walk briskly, I was a house husband for awhile and daily took the kids to school, the unfit and overweight walk slowly the fit and thin walk quickly,... just my little obsevation.