What is the role of physical exercise in Alzheimer's disease review?

Oct 18, 2025 2 min read •

Geriatrics Healthy Aging neurology

According to a meta-analysis involving over 160,000 participants, regular physical activity may reduce the risk of developing Alzheimer's disease (AD) by as much as 45%. This review explores the multifaceted protective mechanisms behind physical exercise, highlighting its crucial role in managing and potentially preventing Alzheimer's disease.

Quick Summary

Regular physical exercise, especially aerobic and multi-component training, acts as a powerful non-pharmacological strategy for delaying the onset and slowing the progression of Alzheimer's disease (AD) by improving cerebral blood flow, reducing inflammation, promoting neurogenesis, and bolstering cognitive function. These benefits are observed through a range of neuroprotective mechanisms, although effectiveness varies with disease stage and exercise specifics.

Key Points

Reduces Risk and Slows Progression: Regular exercise, particularly aerobic activity, has been shown to significantly lower the risk of developing Alzheimer's and can slow the rate of cognitive decline once it begins.
Enhances Brain Structure and Function: Physical activity increases the size of the hippocampus, a brain region crucial for memory that is often affected by AD, and promotes the growth of new neurons (neurogenesis) and blood vessels (angiogenesis).
Modulates AD Pathological Hallmarks: Exercise may help to reduce amyloid-beta plaque accumulation and tau phosphorylation in the brain, two key neuropathological features of Alzheimer's disease.
Combats Inflammation and Oxidative Stress: Regular moderate-intensity exercise has powerful anti-inflammatory effects, helping to regulate the brain's immune response and reduce oxidative stress that can damage neurons.
Optimizes Neurotrophic Factors: Exercise boosts the production of beneficial brain chemicals, notably Brain-Derived Neurotrophic Factor (BDNF), which supports neuronal survival and synaptic plasticity critical for memory and learning.
Integrates into Multimodal Strategies: For the best results, exercise is most effective when combined with other lifestyle interventions, including proper nutrition, cognitive training, and management of vascular risk factors.
Beneficial Across Disease Stages: Although more impactful in early stages or in those with Mild Cognitive Impairment (MCI), exercise still offers cognitive benefits and can improve daily functional activities for those already diagnosed with AD.

The Neuroprotective Mechanisms of Exercise

Physical exercise influences the brain through a cascade of biological and physiological processes that counteract the pathology of Alzheimer's disease (AD). Regular activity provides significant neuroprotective and anti-inflammatory adaptations.

Improved Cerebral Blood Flow (CBF) and Neurogenesis

Exercise supports brain health by enhancing cerebral blood flow, which is often reduced in AD. It promotes the growth of new blood vessels and enhances neurogenesis, particularly in areas like the hippocampus, vital for memory and learning.

Modulating Amyloid-Beta (Aβ) and Tau Pathology

Exercise may help modulate the accumulation of amyloid-beta plaques and tau protein tangles, hallmarks of AD. Research suggests it can reduce Aβ plaque burden and promote clearance, while also reducing tau phosphorylation.

Anti-Inflammatory and Antioxidant Effects

Chronic inflammation is a key factor in AD progression. Exercise offers anti-inflammatory benefits by reducing pro-inflammatory markers and modulating immune cell activity in the brain. It also combats oxidative stress, which contributes to neurodegeneration.

Enhancing Neurotrophic Factors and Brain Volume

Exercise boosts crucial neurotrophic factors like Brain-Derived Neurotrophic Factor (BDNF), supporting neuronal health and plasticity. Long-term exercise can also increase hippocampal volume, countering age-related brain atrophy.

Comparison of Exercise Types and Benefits

While aerobic exercise is well-studied, a balanced approach is beneficial.


Feature	Aerobic Exercise	Resistance Training	Multi-component Training
Key Benefits	Improved cardiovascular fitness, enhanced cerebral blood flow, neurogenesis, reduced risk of dementia.	Increased muscle mass and strength, improved motor function, reduced fall risk.	Combined cognitive and physical benefits, potentially addressing multiple AD risk factors simultaneously.
Cognitive Effects	Positive effects on memory, executive function, and overall cognitive scores, particularly in individuals with Mild Cognitive Impairment (MCI).	Some studies suggest positive effects on executive functions and memory, though evidence is less extensive than for aerobic training.	Potentially superior for overall brain health, leveraging both physical and cognitive components.
Frequency/Intensity	Moderate intensity (e.g., brisk walking, cycling) for at least 150 minutes per week is generally recommended.	At least two days per week, focusing on major muscle groups.	Can vary, often includes 2–3 sessions per week combining aerobic, strength, and balance exercises.
Research Consensus	Strong evidence supporting protective and disease-slowing effects, especially when initiated early.	Promising but requires more consistent research protocols to draw firm conclusions.	Recommended multimodal approaches have shown robust benefits in randomized controlled trials.

Optimal Intervention Timing and Considerations

Exercise is most effective when started early, before significant damage. Consistency is key, as benefits like improved brain perfusion are activity-dependent. Tailoring regimens to individual capabilities is important.

Exercise: A Promising Non-Pharmacological Strategy

Regular physical exercise is a promising strategy for delaying and slowing AD progression, influencing multiple pathways. While effective protocols are still being refined, moderate-intensity aerobic and strength training form a solid foundation.

To learn more about the latest research findings, visit the National Institute on Aging website.

Frequently Asked Questions

Regular physical exercise protects the brain through multiple mechanisms: it increases cerebral blood flow, reduces harmful inflammation, stimulates the production of neurotrophic factors like BDNF, and helps prevent age-related brain shrinkage, particularly in the hippocampus.

While a combination of exercises is best, aerobic exercise is widely studied and highly recommended. Multi-component training that includes aerobic, resistance, and balance exercises offers the most comprehensive benefits for older adults, addressing various aspects of cognitive and physical health.

Yes, reviews show that exercise can improve certain cognitive domains, such as executive function, even in people with existing dementia. While it may not reverse memory loss in advanced stages, it can enhance functional abilities and overall quality of life.

Research suggests that consistent moderate-intensity aerobic exercise, such as 150 minutes per week, can yield significant brain health benefits. Even smaller amounts of moderate-to-vigorous activity can reduce dementia risk, according to a recent study.

The optimal intensity is still a subject of research, but most studies indicate that regular moderate-intensity exercise offers robust benefits with lower risk of injury. For some, high-intensity training may offer slightly different cognitive benefits, but a personalized approach based on individual health is crucial.

Animal studies show that exercise can prevent the accumulation of Aβ protein and may help clear existing plaques, particularly when started early. This modulation contributes to the neuroprotective effects of physical activity against AD.

Exercise is generally safe and beneficial. However, for individuals with AD, supervision may be necessary to ensure safety and proper form, especially with balance exercises. A doctor should be consulted before beginning a new routine, especially if other health issues exist.

References

Medical Disclaimer

This content is for informational purposes only and should not replace professional medical advice. Always consult a qualified healthcare provider regarding personal health decisions.