Back in 2023, researchers pumped the brakes on one of my most cherished beliefs about exercise: the idea that aerobic fitness makes your brain healthier and more resistant to age-related cognitive decline. Exercise, the thinking goes, spurs the production of growth-promoting brain chemicals, or enhances blood flow to the brain, or simply promotes better sleeping habits and healthier social interactions. The idea has been around for decades and is a staple of health journalism. But a major review published in Nature Human Behaviour found that the actual scientific evidence was too weak to conclude that exercise makes you smarter.
So I’m pleased to report a couple of new studies that support the brain benefits of fitness. Both of them rely on VO2 max as a gold-standard objective measure of aerobic fitness, rather than trying to estimate fitness or exercise habits. One finds that higher VO2 max is associated with better cognitive function in older adults; the other finds that it preserves the size of a key brain region as you age. Lately VO2 max has been getting a lot of attention for its ability to…
