Spark

They don’t know that toxic levels of stress erode the connections between the billions of nerve cells in the brain or that chronic depression shrinks certain areas of the brain. And they don’t know that, conversely, exercise unleashes a cascade of neurochemicals and growth factors that can reverse this process, physically bolstering the brain’s infrastructure.

The neurons in the brain connect to one another through “leaves” on treelike branches, and exercise causes those branches to grow and bloom with new buds, thus enhancing brain function at a fundamental level.

Exercise serves as the social lubricant, and it’s crucial to this kind of learning because it reduces anxiousness.

Even adults can make a major shift and recognize how physical activity influences the brain.

The way you choose to cope with stress can change not only how you feel, but also how it transforms the brain. If you react passively or if there is simply no way out, stress can become damaging.

Stress seems to have an effect on the brain similar to that of vaccines on the immune system. In limited doses, it causes brain cells to overcompensate and thus gird themselves against future demands. Neuroscientists call this phenomenon stress inoculation.

Physical activity is the natural way to prevent the negative consequences of stress. When we exercise in response to stress, we’re doing what human beings have evolved to do over the past several million years.

Exercise is particularly important for women because it tones down the negative consequences of hormonal changes that some experience, and for others, it enhances the positive. Overall, exercise balances the system, on a monthly basis as well as during each stage of life, including pregnancy and menopause.

When women are younger, one of the big motivations to exercise is to stay trim, and that’s fine. Use whatever gets you going. But the message I want to leave you with is that even as your body changes, exercise will keep your mind firm and taught. And in this state of mental fitness, you’ll be well equipped to handle the hormonal fluctuations that every woman experiences throughout her life. Not to mention the fluctuations of life itself.

I have faith that when people come to recognize how their lifestyle can improve their health span—living better, not simply longer—they will, at the very least, be more inclined to stay active. And when they come to accept that exercise is as important for the brain as it is for the heart, they’ll commit to it.