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

by Kelly McGonigal

When adults are randomly assigned to reduce their daily step count, 88 percent become more depressed. Within one week of becoming more sedentary, they report a 31 percent decline in life satisfaction. The average daily step count required to induce feelings of anxiety and depression and decrease satisfaction with life is 5,649. The typical American takes 4,774 steps per day. Across the globe, the average is 4,961.

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

Persistence is key to experiencing a high while exercising, but maybe that’s not the best way to think about it. We don’t persist so we can get some neurochemical reward; the high is built into our biology so that we can persist.

I am not a morning person, but I have learned to drag myself out from under the covers, stumble to the kitchen for coffee, and exercise before I do anything else. For me, it’s a survival strategy. I want to face the day as the version of myself who takes over by the time I’m done with my workout: braver, more optimistic, and ready to face whatever challenges await me.

extreme spike in dopamine, endorphins, and other feel-good chemicals. Drugs like cocaine or heroin wallop the system, but exercise merely stimulates it, leading to very different long-term adaptations.

Our brains change as we age, and adults lose up to 13 percent of the dopamine receptors in the reward system with each passing decade. This loss leads to less enjoyment of everyday pleasures, but physical activity can prevent the decline. Compared to their inactive peers, active older adults have reward systems that more closely resemble those of individuals who are decades younger.

After lactate is released by muscles, it travels through the bloodstream to the brain, where it alters your neurochemistry in a way that can reduce anxiety and protect against depression.