Why is walking so good for the brain?

Blame it on the "spontaneous fluctuations". What can you learn from a daily stroll? Contrary to popular belief, research suggests that walking decreases rational thinking and promotes mind-wandering. Thomas Nail, a professor of philosophy, explores why going on a walk makes your mind wander in ways that neuroscience is only just coming to terms with. Here, he reflects on the power of this irrationality and encourages us all to partake.