The brain is cognitively efficient for physical movements and situations you experience regularly. We experience this subjectively as opportunities to “zone out

The brain is cognitively efficient for physical movements and situations you experience regularly. We experience this subjectively as opportunities to “zone out” or let our thoughts wander as we do the activity. If you run the same route regularly, after a few dozen times you’re probably not thinking much about the running itself anymore. People learning new activities experience it as the activity “slowing down” subjectively as they learn, giving them more comfort and greater opportunity to think about further improvements. For example learning to ride a bike requires intense thought. But once you know how to ride a bike, it just happens and you can think about where you’re going, or whether you’re in the right aerobic zone, or how fast to take the next jump, etc. So I would bet that to optimize the cognitive benefit of physical activity, it needs to be somewhat novel. Running on a treadmill or swimming in the same pool or lifting weights in the same gym over and over probably would not do it. You’d need some sort of sport (where other players are constantly creating novel situations) or an outdoor sport where natural conditions are always changing. Or frequently trying new sports or activities.