True, there's no home-gym equipment designed to build up your brain muscle. But a simple walk just might increase your brain size.
Studies show that regular cardiovascular exercise, like walking, is good for your brain because it can enlarge the hippocampus—a small, curved, seahorse-shaped structure in your brain that is vital to memory function. Damage or deterioration of the hippocampus can lead to memory problems, and may even prevent new memories from being formed. In fact, Alzheimer’s disease heavily affects the hippocampus. The rapid loss of tissue during the early stages of the illness may be a reason people with Alzheimer’s experience memory loss.
The good news is that your habits can improve the health of your hippocampus,.
Exercise and hippocampus size
A 2021 meta-analysis published in Hippocampus looked at 22 studies and found that aerobic exercise had significant positive effects on left-hippocampus volume by preventing decreases in size over time. In other words, aerobic exercise prevented deterioration of the area of the brain that is typically associated with aging and memory.
Another study, published in 2019 in Brain Imaging and Behavior, examined 39 mostly sedentary people who either had 16 weeks of progressive aerobic exercise or no change in physical activity. People who exercised saw hippocampus-specific brain volume increases, while those in the group who didn’t exercise experienced no improvement. In fact, older adults in the control group actually showed a decrease in hippocampus size.
That’s not all. Exercise also led to a better mood. People who were active boosted their “vigor”—defined as being lively, active, energetic, cheerful, alert, full of pep, carefree, and vigorous. Over the course of the study, vigor notably decreased in the control group.
Exercise and memory
The hippocampus tends to decrease in size as we age. When this area of the brain shrinks, our memory can wane, as well. But according to the evidence, exercise is a proven, non-pharmaceutical way to improve your ability to remember.
A 2017 study published in Neuroimage looked at the relationship between aerobic fitness and hippocampal “viscoelasticity”—a measure of tissue health. Higher viscoelasticity signals better performance in relational memory tasks, such as remembering names and faces. Researchers found that a higher fitness level was linked to better hippocampal viscoelasticity, which in turn predicted better memory recall.
Studies have also been conducted that look directly at the effects of aerobic exercise on memory. A meta-analysis of 36 studies, published in 2022 in Communications Medicines, found that aerobic exercise positively influenced episodic memory—the type of memory consisting of past personal events and experiences.
While we can’t avoid all the effects of aging, we can work to keep our brains big and strong with aerobic exercise, potentially slowing or staving off cognitive decline. And we can start by taking one step at a time.
Aerobic exercise: How to get started
An easy and efficient way to increase aerobic fitness is to go for a walk. The federal government recommends that adults get at least 150 minutes of moderate-intensity aerobic exercise per week. The guidelines note that any activity that gets your heart rate beating faster than normal counts, including walking.
If walking is not for you, try biking, swimming, dancing, playing a sport, pushing a lawnmower, doing some gardening, or any other enjoyable activity that gets you moving. Be sure to start slowly and ease your way into more exercise.
If you find it difficult to do longer exercise sessions, break it up into smaller chunks throughout the day. A 10-minute walk, done two or three times a day, still counts towards your weekly total, and every minute of extra activity helps. Even five minutes of aerobic activity each day is better than none at all.
The brain is a complex organ. But activities that get the heart pumping are a good way to help keep it healthy—and perhaps, increase its size.
Sources: Wilckens KA, Stillman CM, Waiwood AM, et... + 10
- Wilckens KA, Stillman CM, Waiwood AM, et al. Exercise interventions preserve hippocampal volume: A meta‐analysis. Hippocampus. 2020;31(3):335-347.
- Frodl T, Strehl K, Carballedo A, et al. Aerobic exercise increases hippocampal subfield volumes in younger adults and prevents volume decline in the elderly. Brain Imaging and Behavior. 2019;14(5):1577-1587.
- Johns Hopkins Medicine. Brain Anatomy and How the Brain Works. Published 2019.
- Fogwe LA, Mesfin FB. Neuroanatomy, Hippocampus. In: StatPearls. Published February 28, 2019.
- Rao YL, Ganaraja B, Murlimanju BV, et al. Hippocampus and its involvement in Alzheimer’s disease: a review. 3 Biotech. 2022;12(2).
- Nobis L, Manohar SG, Smith SM, et al. Hippocampal volume across age: Nomograms derived from over 19,700 people in UK Biobank. NeuroImage: Clinical. 2019;23:101904.
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- U.S Department of Health and Human Services. Physical Activity Guidelines for Americans. 2018.
- National Science Foundation. How sleep builds relational memory. June 14, 2022.
- Harvard Health Publishing. Exercise can boost your memory and thinking skills. February 15, 2021.
- Aghjayan SL, Bournias T, et al. Aerobic exercise improves episodic memory in late adulthood: a systematic review and meta-analysis. Communications Medicine. 2022;2(15).
