EXERCISE: Small Steps, Big Impact on Cognitive Health

For many older adults, the idea of hitting the gym for high-intensity workouts can feel overwhelming or out of reach. But research offers reassuring news: even light exercise can make a meaningful difference in brain health — especially for those at risk of dementia.

Why This Matters

Mild cognitive impairment (MCI) is a condition that affects memory and thinking skills and is considered an early warning sign for Alzheimer’s disease and other forms of dementia. While not everyone with MCI will go on to develop dementia, around 10–15% do. That makes early intervention essential — and exercise may be one of the most accessible and impactful tools we have.

What the Research Found

Two recent studies from the EXERT trial, published in Alzheimer’s and Dementia: The Journal of the Alzheimer’s Association, offer compelling evidence that both low and moderate-to-high-intensity exercise can slow cognitive decline in older adults with amnestic MCI (aMCI), the subtype of MCI most closely linked to memory loss.

• Study 1: 296 older adults with aMCI were randomly assigned to either:

  
  

  • Moderate-high intensity aerobic training, or

  • Low-intensity stretching, balance, and mobility exercises.

    
    

    Both groups exercised 3–4 times a week for 30–45 minutes.

  • 
    

• Results: After 12 months, both groups showed less cognitive decline than peers who remained sedentary.

• 
  

• Brain Imaging: Participants in both exercise groups also showed reduced brain volume loss — particularly in the prefrontal cortex, a region responsible for attention, planning, and organizing.

What Makes Light Exercise So Effective?

Light exercise — like stretching, slow walking, or balance work — might not leave you breathless, but it still gets the blood moving. That matters because brain health is closely tied to blood flow.

Dr. Laura Baker, lead author of the EXERT study, explained that these kinds of gentle movements help sustain brain tissue and may protect against the loss of neurons, especially in brain areas linked to executive function.

A Crucial Window for Action

One of the most important findings wasn’t just what kind of exercise helps — but when it helps. People with aMCI are often still functioning well day to day, but their memory issues are real. Unfortunately, because the symptoms are subtle, these individuals may not be referred for help until dementia has already begun to set in.

That’s why these findings are so vital. They show that regular exercise — even low-intensity — during this early phase can preserve cognitive function and potentially delay the onset of dementia.

What Does This Mean for You?

If you or someone you care about is experiencing mild memory issues, these studies underscore a hopeful message: you don’t have to run marathons to protect your brain.

Here’s what researchers and neurologists recommend:

• Move regularly: Aim for 30–45 minutes of activity, 3–4 times per week.

• Keep it simple: Walking, stretching, or light balance exercises are enough.

• Be consistent: Long-term, regular activity matters more than intensity.

• Start early: If memory concerns arise, don’t wait — begin an exercise routine now.

• Combine strategies: A healthy diet, social connection, and ongoing learning further protect the brain.

How Aging Affects the Brain

Aging naturally involves some loss of brain volume, but the rate of loss can vary widely. People with memory problems that worsen over time tend to lose brain volume more quickly. Exercise appears to slow this shrinkage, preserving cognitive functions for longer.

Dr. Aladdin Shadyab, another lead researcher, explained that preventing volume loss in the prefrontal cortex may help people maintain the ability to focus, plan, and organize — crucial skills for independence in older age.

Supporting a Brain-Healthy Lifestyle

According to Dr. Lycia Neumann from the Alzheimer’s Association, these studies strengthen the case for treating physical activity as a pillar of brain health. While no single solution exists to prevent Alzheimer’s disease, lifestyle changes — especially regular movement — offer a low-risk, high-reward approach.

Even if you carry genetic risk factors for dementia, making small, regular changes to your lifestyle can have a powerful impact on your long-term brain function.

Final Thoughts

Exercise doesn’t need to be intense to be effective. What matters most is doing it often — and starting before dementia has taken hold. By adding light movement to your week, you’re not just supporting your body. You’re investing in your brain.

---

Evidence List

1. Baker LD et al. (2024). Effects of Aerobic and Stretching Exercise on Cognition in Older Adults with Amnestic Mild Cognitive Impairment: Primary Results of the EXERT Trial. Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.

   
   

   → This primary study from the EXERT trial followed 296 sedentary older adults with aMCI for 12 months. It found that both moderate-high intensity aerobic exercise and low-intensity stretching helped stabilize cognitive function compared to no exercise. The findings suggest that even light physical activity, done consistently, can slow cognitive decline.

1. Shadyab AH et al. (2024). Brain Volume Changes and Physical Activity in Older Adults with Amnestic Mild Cognitive Impairment: Imaging Results from the EXERT-ADNI Substudy. Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.

   
   

   → This imaging-focused substudy of EXERT (called EXERT-ADNI) analyzed MRI data from participants and showed that those in both exercise groups experienced less brain volume loss over 12 months — particularly in the prefrontal cortex, a key region for attention, planning, and executive function.

1. Alzheimer’s Association (2023). 10 Healthy Habits for Your Brain.

   
   

   → Offers practical, evidence-informed lifestyle strategies to protect brain health. Recommends regular physical activity as one of the key modifiable factors for reducing the risk of cognitive decline.

1. Medical News Today (2024). Light Exercise May Slow Brain Decline in At-Risk Adults.

   
   

   → A summary and expert commentary on the EXERT findings, including insights from study authors Laura Baker, PhD, and Aladdin Shadyab, PhD, on how exercise supports brain health in older adults with MCI.