The Joy of Movement: How Exercise Helps Us Find Happiness, Hope, Connection, and Courage

by Kelly McGonigal

For one thing, it suggests that the key to unlocking the runner’s high is not the physical action of running itself, but its continuous moderate intensity.

You just have to do something that is moderately difficult for you and stick with it for at least twenty minutes. That’s because the runner’s high isn’t a running high. It’s a persistence high. —