Exercising to Grow Your Brain

by Amylee Amos PhD, RDN, IFMCPLifestyle
Person running up stairs in athletic shoes

You know that exercise is important. We’re told that we need to exercise about as often as we’re told we need to eat more vegetables (by the way, you really should eat more vegetables). And yet most of us underestimate just how impactful exercise can be, specifically for brain health. Normally talk of exercise revolves around weight management, maintenance of lean body mass, mood elevation, and chronic disease prevention, just to name a few. All of these are great reasons to exercise. But if you’re concerned about your cognitive health, here’s some major inspiration to get your exercise regimen on point. In the last several years, research has shown that exercise can physically increase brain volume. I’ll say that again, just in case it didn't fully sink in: research shows that exercise can physically increase brain volume!

To put it more specifically, in Alzheimer’s patients we often see dramatic shrinkage in the hippocampal region of the brain, the part of the brain that stores memories. Average brain shrinkage in this region is about 1-2% annually in dementia patients (1). This loss of brain matter is significant, and it perpetuates the memory loss and progressive decline of the disease. Even in cognitively healthy individuals, the brain modestly shrinks as we age. This may account for the general forgetfulness associated with older adults who do not present with dementia or Alzheimer’s disease. I’m sure I don’t need to tell you that maintaining our brain volume is desirable, regardless of our age. The exciting news is that physical activity, specifically aerobic exercise over the course of a year, was shown in a clinical trial to increase hippocampal volume by 2% in dementia patients. Control subjects who did not exercise in this study lost nearly 1.5% of their brain volume throughout the year (2). So rather than the hippocampal shrinkage we know to expect in dementia, the individuals in this study who exercised had their brain matter literally grow back.

What that means is that exercise alone is far more powerful than anything available pharmaceutically. There is no pill on the market that can physically increase brain volume, yet regular aerobic exercise can. Exercise training, something that anyone and everyone can do, increases the physical size of the hippocampus and improves memory. It is the low cost interventions such as this that are the most powerful. You don’t need to have a personal trainer to exercise, you don’t need to go to the fanciest gym, or have the smartest doctor, or most innovative healthcare team. You don’t need to be an elite athlete or look great in yoga pants. You just need to exercise. Specifically, you need to engage in moderate intensity aerobic activity at least three times per week (2), although you may as well give your brain and body a boost and engage in aerobic activity and resistance training at least five times per week.

Research like this indicates that the brain is plastic, able to change and grow, well into older adulthood. In other words, it’s never too late to change your brain, and that can either work for us or against us. We need to care for our brain health throughout life. Exercise is a powerful epigenetic event than can enhance creation of new brain cells. And anyone can do it, including you. Get out there are start growing brain matter today!


  1. Raz N, et al. (2005). Regional brain changes in aging healthy adults: General trends, individual differences and modifiers. Cereb Cortex, 15:1676–1689.
  2. Erickson, K. et al. (2011). Exercise training increases size of hippocampus and improves memory. Proceedings of the National Academy of Sciences of the United States of America, 108(7), 3017–3022.