This is why I think trail running is so valuable. You must be aware of your changing environment and how to adjust your body's movement to accommodate. You are exercising your mind to calculate your current momentum, intended placement of your next step, and it's potential impact to the rest of your body. You are running your own mental physics simulation as you work the trail, nothing like running on regular roads.

This sounds a lot like why I find BMX racing less interesting than I thought I would.

It’s also why I make the kids ride elsewhere. Snow provides good physics lessons on traction and centre of gravity.