ST, my folks used to be into
Power Walking when I was a kid. And boy-oh-boy was it embarrassing.
As best as I can remember it,
Power Walking is a lot like walking except that you also pump your arms enthusiastically and twist your hips with each step. The idea is to get the maximum benefit from each motion. By getting your arms and hips into the mix, you end up working-out more muscle-groups (and burning more calories).
But try telling that to a ten-year old kid.
I remember having to go to a public park with my folks (and their
Power Walking buddies) and having to (power) walk passed a bunch of bikers who were hanging out there (and probably getting high). It's hard to imagine why but they found our motion to be rather amusing ...