The idea that exercise can grow your brain sounds like a bold claim. Two decades of research on exercise and brain health have produced compelling evidence. The hippocampus, a small region deep in the brain involved in memory and navigation, can respond to regular movement even in older adulthood.
The direct answer is yes, with important caveats. Regular aerobic and movement-based exercise may help preserve or modestly increase hippocampal volume in healthy older adults. This is not a treatment for dementia, Alzheimer’s disease, or diagnosed cognitive decline, and it should not be framed as one.
This article unpacks two landmark studies, explains brain-derived neurotrophic factor (BDNF) in plain language, and outlines a PT-built movement plan for adults over 60. At Primal Physical Therapy, movement specialists translate this research into safe starting points matched to your current ability.
What Is the Hippocampus, and Does It Shrink With Age?
The hippocampus is a seahorse-shaped structure seated deep in the temporal lobe. It helps form new memories, supports learning, and aids spatial navigation. Think of it as part of the brain’s filing and mapping system.
Even without a dementia diagnosis, healthy older adults experience natural volume loss in this region. Hippocampal volume shrinks roughly 1 to 2 percent annually in sedentary older adults. That volume loss does not guarantee memory problems, but research suggests it may relate to gradual changes in memory and spatial orientation over time.
This is precisely why exercise and brain health research has focused so closely on the hippocampus. If consistent movement can offset that shrinkage, even partially, the implications for healthy aging are significant.
Can Exercise Increase Hippocampus Size? The 120-Person Walking Trial
The clearest evidence comes from Erickson and colleagues (2011), published in the Proceedings of the National Academy of Sciences. This randomized controlled trial enrolled 120 sedentary, dementia-free older adults with a mean age of approximately 66.
Participants were divided into two groups. One group completed progressive walking three times per week, building toward 40 minutes per session at 50 to 75 percent of heart-rate reserve. The other group performed stretching and toning as a control. The trial lasted one year.
After 12 months, the walking group increased anterior hippocampal volume by approximately 2.12 percent on the left side and 1.97 percent on the right. The stretching-and-toning group declined by approximately 1.40 percent on the left and 1.43 percent on the right. The researchers noted that this difference offset roughly 1 to 2 years of typical age-related hippocampal volume loss.
These are MRI measurements of brain volume, not direct observations of new neurons. The study captured structural size changes. It did not observe new brain cells growing in individual participants.
Did Walking Improve Memory? What the Study Actually Found
The hippocampal volume gains are striking. The memory results require a more careful reading.
Both the walking and stretching-and-toning groups improved on the spatial memory task over the year. The walking group’s improvement was not significantly greater than the stretching group’s. There was no significant Time x Group interaction for the memory outcome. Volume gains occurred in the walking group; memory gains occurred in both.
Researchers did find meaningful associations within the data. Better aerobic fitness and larger hippocampal volume were associated with better spatial memory performance across participants. However, associations are not cause and effect. The study cannot establish that hippocampal volume growth directly caused the memory improvement.
Walking supports fitness, hippocampal volume trends, and general well-being. The evidence does not show it delivers a memory benefit that structured stretching and toning cannot also produce. Both forms of organized physical activity appear to support spatial memory in healthy older adults.
What Is BDNF and How Does Exercise Raise It?
BDNF stands for brain-derived neurotrophic factor. It is a protein linked to the growth of new neurons and to the survival and adaptability of existing ones. Among the walking group in the Erickson study, increases in serum BDNF (BDNF measured in blood) correlated with gains in hippocampal volume.
This finding points toward a possible biological pathway: aerobic exercise may raise circulating BDNF, and higher BDNF may support the structural changes observed in the hippocampus. BDNF was measured in blood serum, not in brain tissue. The study did not observe new neurons growing in participants. A rise in serum BDNF is not the same as confirmed neurogenesis in the human brain.
The practical implication is simpler than the biology. A consistent aerobic routine that improves cardiovascular fitness appears to support the environment in which hippocampal health can be maintained. That is a compelling reason to move regularly, even while the exact mechanisms continue to be studied.
Is Dancing Better for the Brain Than Regular Exercise?
A 2017 trial by Rehfeld and colleagues, published in Frontiers in Human Neuroscience, approached exercise and brain health from a different angle. What happens when movement requires constant learning?
The study enrolled 62 older adults with a mean age of approximately 68. The dance program used constantly changing choreography, new rhythms, and unfamiliar movement sequences. The fitness group repeated more familiar endurance and flexibility routines. After 18 months, 26 participants (of 62 enrolled) finished the full protocol: 14 in the dance group and 12 in the fitness group.
Both groups showed changes in hippocampal subregions, including the left CA1, CA2, and subiculum. Dancers additionally showed growth in the left dentate gyrus and right subiculum beyond the shared regions. Critically, only the dance group significantly improved the study’s balance composite score.
| Exercise Type | Hippocampal Volume Change | Memory Effect | Balance Benefit | Best For |
|---|---|---|---|---|
| Aerobic Walking | +2.12% left / +1.97% right anterior hippocampus (Erickson 2011) | Both groups improved equally; no significant group difference | Not the primary measure in this trial | Aerobic foundation; most accessible starting point |
| Dance/Choreography | Left dentate gyrus + right subiculum gains beyond shared regions (Rehfeld 2017) | Both dance and fitness groups showed hippocampal subregion changes | Significant improvement in dance group only | Combining aerobic work with novelty and balance challenges |
| Strength Training | Limited specific hippocampal data from reviewed trials | Supports overall physical function and fitness foundation | Indirect benefit through fall prevention and muscle strength | Rebuilding baseline strength; managing joint conditions |
| Stretching/Toning (control) | -1.40% left / -1.43% right anterior hippocampus (Erickson 2011) | Both groups improved equally; no significant group difference | Not the primary measure in this trial | Low-intensity option for those with significant mobility limits |
Why Learning New Movements Matters for Brain Health
The Rehfeld study does not prove that dance is universally superior to walking for memory. Both groups showed hippocampal changes. The sample was small, and the absence of a true inactive control limits interpretation.
What it does suggest is that novelty and coordination may complement steady aerobic work. A familiar walk challenges your cardiovascular system. Learning a new sequence of steps also requires attention, timing, direction changes, and recall. These demands may engage different aspects of brain function that repetitive exercise does not.
You do not need formal dance training to apply this principle. Try a beginner dance video, patterned side-steps, a short four-step sequence changed weekly, or a different walking route with turns and direction changes. Movement analysis can help identify safe coordination challenges based on your current mobility and strength.
How Much Exercise Do You Need for Brain Health?
The Physical Activity Guidelines for Americans, 2nd edition (HHS 2018), provide the clearest framework. For meaningful exercise and brain health benefits, older adults should work toward:
- 150 to 300 minutes of moderate aerobic activity per week
- Muscle-strengthening activities on two or more days per week
- Balance training incorporated into the weekly routine
- Coordination challenges that require learning and adaptation
The Erickson study used progressive walking three times per week, building toward 40 minutes per session at moderate intensity. A 2021 meta-analysis by Wilckens and colleagues reviewed 23 exercise interventions and found significant positive effects on total hippocampal volume in adults aged 65 and older and in programs lasting more than 24 weeks. Duration and consistency appear to matter more than brief intense efforts.
| Day/Frequency | Activity | Duration | Intensity Note |
|---|---|---|---|
| 3 days per week | Aerobic walking | 20 to 40 minutes | Talk test: speak in phrases, not sing; build toward 40 min over weeks |
| 1 to 2 days per week | Coordination or dance | 10 to 20 minutes | Moderate; change choreography or step pattern every 1 to 2 weeks |
| 2 days per week | Strength training | 30 to 45 minutes | Challenging but controlled; slow deliberate movement throughout |
| Most days (brief) | Balance practice | 5 to 10 minutes | Start with support; progress to unsupported only when stable |
Starting below these targets still counts. Consistent moderate effort repeated over months produced the hippocampal changes in the Erickson trial. A 10-minute walk is a legitimate starting point.
A Brain-Friendly Movement Plan for Adults Over 60
Walking
Walk three days per week at a pace where you can speak in short phrases but not sing. A 20- to 30-minute session is a practical starting point. Build toward 30 to 40 minutes as fitness improves over weeks.
If joint pain, a noticeable limp, or uncertainty about mechanics makes walking feel unsafe, a gait analysis can identify modifications before you add more mileage.
Coordination and Dance
Add one to two coordination-focused sessions per week, 10 to 20 minutes each. Choose a beginner dance video, a simple patterned side-step sequence, or a movement routine with direction changes. Change the sequence or choreography every one to two weeks to keep the learning element active.
Movement analysis can help match coordination challenges to your current ability and flag balance or strength concerns before you progress.
Strength Training
Train for strength twice per week. Prioritize sit-to-stands, supported squats, step-ups when appropriate, rows, presses, and calf raises. Work at a resistance level that feels challenging while maintaining slow, controlled movement throughout. Primal’s strength and conditioning program provides structured progression for older adults with varying fitness starting points.
Balance
Practice balance in brief doses most days. Most people don’t realize how important visual eye-tracking exercises are for preserving balance as we age. These exercises help coordinate the eyes, brain, and body and can be practiced even from a seated position. As balance improves, progress to more challenging positions such as half-kneeling, supported tandem standing, weight shifts, and heel-to-toe walking beside a stable counter. Short, frequent sessions can help build balance confidence and reinforce these skills over time.
When to See a Physical Therapist Before You Start
Many healthy adults can begin a walking and movement routine without a clinical assessment. Start with 10 minutes, finish feeling steady, and progress gradually. That modest start was the foundation of the Erickson trial’s walking protocol.
Seek medical evaluation before exercising if you experience new or worsening chest pain, severe shortness of breath, fainting, or other urgent symptoms.
Consider a physical therapy assessment before advancing if you have had recent surgery, a significant injury, repeated falls, persistent joint pain, a noticeable limp, or fear of movement. Arthritis, old injuries, and deconditioning do not automatically rule out exercise, but they often change your starting dose, footwear, surface choices, or exercise selection.
Physical therapy can address pain, strength, and movement limitations, but it does not diagnose or treat dementia. Discuss new, progressive, or concerning memory symptoms with your physician or a qualified medical clinician.
For a structured return after injury, read our guide on how to return to exercise safely after injury. For a personalized progression plan, explore Primal’s strength and conditioning program.
Exercise and Brain Health FAQ
Can exercise really grow your brain?
Yes, within specific research parameters. A 2011 randomized trial found that healthy older adults who completed one year of progressive walking increased anterior hippocampal volume by approximately 2 percent. The stretching-and-toning group declined instead. MRI captures brain volume, not individual new neurons. Results vary by individual health, fitness baseline, and consistency. (Study DOI: 10.1073/pnas.1015950108)
Does walking help with memory?
Walking supports overall brain health and appears to benefit hippocampal structure in healthy older adults. In the Erickson 2011 trial, both walkers and stretchers improved on spatial memory, with no significant difference between groups. Consistent walking improves fitness and may support the conditions for healthy brain structure over months of sustained effort.
Is dancing better than walking for brain health?
Not conclusively. Both groups in the Rehfeld 2017 study showed hippocampal changes. Dance produced additional subregion growth and was the only group to significantly improve balance scores. The trial had only 26 participants (of 62 enrolled), so results are preliminary. Dance may add value through novelty and coordination demands rather than replacing aerobic walking as the foundation.
How long does it take for exercise to affect the brain?
The Erickson trial ran for one year at three sessions per week. The Wilckens 2021 meta-analysis found significant hippocampal effects in programs lasting more than 24 weeks. Short-term benefits for mood and cognitive sharpness may appear sooner, but structural brain changes appear to require sustained, consistent effort over several months.
Is it too late to start exercising for brain health at 70?
No. The Erickson 2011 trial enrolled sedentary adults with a mean age of approximately 66, and the Wilckens 2021 meta-analysis found significant effects specifically in adults aged 65 and older. Beginning with modest, consistent movement is supported by evidence within older adulthood. Consult your physician if you have significant health concerns before starting a new exercise program.
