And here's another benefit of walking: It improves your memory. That's according to a study by Sabine Schäfer, a psychologist at the Max Planck Institute.
Schaefer's team had 32 nine-year-olds and 32 adults (average age 25) complete the N-back working memory task in three conditions: walking on a treadmill at their own chosen speed; walking on a treadmill at a set speed chosen by the researchers; or sitting down. The N-back task requires that participants listen to a stream of numbers and indicate, in the easiest version, whenever the current number was the same as the number one back. For more difficult versions, it's a repeat of a number further back in the stream that must be spotted.
The headline finding was that the working memory performance of both age groups improved when walking at their chosen speed compared with when sitting or walking at a fixed speed set by the researchers.
The hypothesis is that walking increases general "arousal and activation," which musters resources that can be used for cognitive tasks. When I was studying for tests in high school and college I'd often pace around in circles, and while I didn't have any data to back it up at the time, I think I did it because it kept me from sliding into resting mode.
At any rate, this interesting for a few reasons. First, it's just another good reason to do more walking in your life.
But it also has implications for education. People often think an "inability to sit still" gets in the way of academic achievement when, in fact, physical activity and cognition are often complementary. We've done a very bad job of incorporating that reality into our schools. In fact, Schäfer thinks this research might help people design better education programs for kids with ADHD.