Double duty here working out and Pokémon Go.
& incidentally I really need to evolve my feebas into rare, meta milotic
Pokemon go works by GPS, not like a step counter. If you stand in one place while walking the gps doesnt register any distance.
There was a "Poke'Walker" before Pokemon Go came along, but you could just shake it in your hand for steps too.
I'd mostly used riding my bike to grind experience.
I got an Ice Age step counter out of a cereal box when I was a kid and I wanted to see how high of a number it would register so I tried doing this. Shaking it to fast would make it rest though so eventually I gave up. I dont think I ever got past 500 but the screen was wide enough for at least another digit or 2