"Old age comes on suddenly, and not gradually as is thought." Emily Dickinson
I've posted quite a bit about walking lately, and this essay by Ferris Jabr at The New Yorker got my attention not just for explaining the benefits of walking so clearly but also for its appreciation of Mrs. Dalloway, which I'm only about 40 pages from finishing.
What is it about walking, in particular, that makes it so amenable to thinking and writing? The answer begins with changes to our chemistry. When we go for a walk, the heart pumps faster, circulating more blood and oxygen not just to the muscles but to all the organs—including the brain. Many experiments have shown that after or during exercise, even very mild exertion, people perform better on tests of memory and attention. Walking on a regular basis also promotes new connections between brain cells, staves off the usual withering of brain tissue that comes with age, increases the volume of the hippocampus (a brain region crucial for memory), and elevates levels of molecules that both stimulate the growth of new neurons and transmit messages between them.