When I was in college, I found that some of the smartest guys and gals were the varsity athletes. It seemed that at least a couple times a season, the play-by-play guys broadcasting our football games pointed out the GPA of the offensive linemen on our team and how high it was - and not in easy majors, either. No, we're talking engineering, the sciences, etc. Hard stuff. Some people like to play that off to lessons learned from having to manage their time better, and that certainly will play a role, but perhaps there's an additional reason.
Along comes The Primal Blueprint author Mark Sisson, pulling together a group of studies on both rats and humans that indicate the importance and effectiveness of strength training. Not only does he show that rats and humans that perform regular strength training in short bursts of full-body exercise increase brain function, he also shows the effects of unhealthy exercise on brain function (due to higher cortisol release).
Also, the body as a system instead of a bunch of component parts is clearly on display here, as Sisson points out:
"you’re not “just” training your muscles as most people imagine (physical restructuring of the muscle). You’re training the muscle, the energy pathways, the brain, the CNS, and anything else that’s involved in moving your body against a resisting force. And as we know, training something improves it, or, rather, it motivates something to improve itself. This is true for both brain and brawn."And another benefit of such exercise is improved sleep. Studies of weight training (combined with walking) in nursing home patients have shown improved sleep to be a result, and the stress-reducing factors in such exercise (as well as your increased sleep effectiveness) will also improve brain function by reducing the negative effects of stress on learning.
So pick up some weights. Or do some push-ups and free squats till you're huffing and puffing a bit. And hit the road for a good long hike/walk today. Your body and your mind will both thank you!