I have the feeling that "yomping" is a very Brit sort of word - a portmanteau signifying youth and stomping (?) The action, though, I'm sure is fairly universal - it's what fit people do when they are in a hurry - like when you are twenty miles away from your destination 2½ hours before supper is about to be served, when you know they'll neither wait for you nor keep anything!

The other reason for yomping is to show off - to prove that you are fitter than the others, or whatever. You sure as [whistle] don't get to see to enjoy the countryside that way, but you can boast about your prowess!

What names (other than approbrious ones!) do you-all have for this sort of activity?