“Never hurry; take plenty of exercise; always be cheerful, and take all the sleep you need, and you may expect to 
be well. ”
— J.F. Clarke
In Parts 1 and 2 of this series I discussed how exercise enhances cognitive function and how exercise helps you look and feel younger. In this final article of the series, I review the book Spark, and examine how exercise impacts memory and the ability to focus.
In his fascinating, easy-to-read, impeccably-researched book Spark, John J. Ratey, MD, discusses how to “supercharge your mental circuits to beat stress, sharpen your thinking, lift your mood, boost your memory, and much more.” Sounds like a tall order, but it’s not hyperbolic: in addition to everything it does for your body, exercise really does strengthen your brain.
Exercise is critical for those with attention issues, whether they’ve got ADHD, or just have a hard time sitting still and concentrating sometimes. We already know that ADHD affects learning in that being scattered and unfocused make it hard to absorb new ideas or materials, and even harder to do the lengthy and focused practice required of many new skills. It turns out that even a single, ten-minute exercise session in an academic setting increases attention and problem-solving skills of children. And with exercise, more (up to a point) is generally better: if ten minutes is good, thirty is great. Cardiovascular exercise is key for reaping these benefits; though studies have shown that yoga, stretching, and weight training can improve mood and provide a host of health benefits, you need to get your heart rate up, and keep it up, to see the benefits of improved cognitive function.
So how much exercise do you need to really see changes in your brain? Dr. Ratey suggests what I’ve long advocated; first, get fit, then continue to challenge yourself. “The research consistently shows that the more fit you are, the more resilient your brain becomes, and the better it functions both cognitively and psychologically. If you get your body in shape, the mind will follow[1] .”
And I’m in complete agreement with him that you don’t have to climb mountains or take kickboxing to see results (though these are fine activities for those who are so inclined). Some of the most impressive research has been done on subjects who walked briskly each day, and did no other additional exercise. My advice for making your brain healthier through exercise is the exactly the same as it is for getting the rest of your body to perform optimally: start slowly, especially if you are overweight. If kids are scoring higher on tests, solving problems more quickly, and are better able to focus attention on their schoolwork on the days that they exercise vigorously in the morning, shouldn’t they, and we, be exercising every morning?
The answer is yes, and it has huge implications for how children, and even aging adults, learn. Imagine if decreased cognition wasn’t an inevitable part of aging, and if you could not only maintain your working memory, but also become a better problem-solver, as you got older.
The reasons that exercise makes us smarter are varied. The first and most obvious is that the increased blood circulation to the brain leads to sharper thinking. But there’s more to it than that. “Exercise influences learning directly, at the cellular level, improving the brain’s potential to log in and process new information[2] .” For several hours after exercise, your ability to focus increases substantially. Dr. Ratey calls it Miracle-gro for the brain, and it’s the result of the increased blood flow and elevated levels of the protein BDNF that allow the brain to function better. And the brain actually remembers more when it is active. All of these exercise-related factors, and a host of others, serve to enhance learning (not to mention mood and fitness).
As someone who lost my mother to Alzheimer’s, I desperately want to see dementia eradicated, not just for my kids and me, but for everyone. I wish that fifteen years ago I’d known what we know now about the new science of exercise and the brain. We’ve known for decades that exercise helps with depression, but we are now beginning to understand that the very best thing you can do to increase brain function, at any age, is to exercise.