walk (one) off (one's) feet
To exhaust one by making them walk very fast or for a very long distance. The kids have been stuck inside all day, so I think I'll take them out and walk them off their feet. I'm so out of shape that my mother walked me off my feet!
walk someone off their feet (or legs)
exhaust a person with walking.walk somebody off their ˈfeet
(informal) make somebody walk so far or so fast that they are very tired: She may be over seventy, but I’m sure she could walk some of you younger ones off your feet.