Meditation, like exercise, can be a lot of things.

Choosing a brief walk can be exercise, or a brisk walk that's a little longer - maybe doing some forms of housework can be exercise. But exercise can also be running marathons, swimming laps, playing street hockey, dancing in your kitchen, skateboarding or messing around on the monkey bars. Those would all make you feel your body in various ways, both during and after the fact.

I do think your empty mind train rides can be meditation. The fact that much more intense or demanding forms of practice exists does not invalidate that.

(To belabour the metaphor a bit, regarding potential dangers - if somebody has a knee injury, some forms of exercise will be safer for them than others. Take care of yourself!)