I've mentioned in previous posts that I'm syncing my arm movement with my legs. When my left foot goes forward, my right arm goes forward. And likewise with the other leg and arm. I was thinking about this during a recent run, and I realized there is an important benefit from moving my legs and arms this way.
In explaining this, I'm going to refer to a theory of brain activity that was popular a decade or so ago. I don't know if this theory is still in vogue, but I like the theory because it is easy to understand. So, here goes.
When I move my left arm or left leg, that movement is controlled by the right side of my brain. When I move my right arm or right leg that movement is controlled by the left side of my brain. This means that when I run, because I'm syncing my arms and legs together both sides of my brain are active at the same time, rather than alternating being active as would be the case if my left arm and left leg went forward at the same time.
The conclusion that I draw about this is that I'm getting twice the brain activity because I'm syncing my left foot and my right arm.