Having worked with older adults since the late 2000s, I strongly believe that one of the most feared diagnoses amongst this demographic is the onset of dementia. Whilst every health condition and disease has risk factors (both modifiable and non-modifiable), there is a sense amongst the community that dementia strikes at random, meaning there is little that can be done to avoid receiving this dreaded news. Many of us have been personally touched by this condition – my maternal Grandad, the legendary Keith Hill, experienced stark cognitive decline in his 70s before sadly passing at the age of 77 back in 2006.

Of course, Grandad Keith is one of many when it comes to dementia diagnosis (and associated death related to dementia). In 2025, it is estimated there are 433,300 Australians living with dementia. Without significant intervention, this number is projected to rise to about 812,500 by 2054. Dementia has recently become the leading cause of death in Australia – in 2023 it accounted for approximately 17,400 deaths, about 9.5% of all deaths.

Global deaths related to dementia have sharply increased over recent decades. In 1990, there were about 0.56 million deaths due to dementia globally; by 2019 that had increased to around 1.62 million (a x3 increase in under 30 years). Projections suggest that by 2050, dementia‑related deaths could reach 4.91 million annually globally. This is particularly shocking to learn, knowing that we have an ageing population, and I will personally celebrate my 65th birthday in 2050 😳

It all sounds quite doom and gloom’y doesn’t it.

However, as our understanding of dementia and its different types improves (incl. Alzheimer’s Disease, which is the most common type of dementia responsible for 60-70% of cases), our ability to integrate risk-reducing strategies into our daily lives at any age will pay dividends, both on a personal and societal level.

Today I will discuss the role exercise plays in maintaining your cognitive health as we age. Take the power back today, and learn the three reasons why aerobic exercise is a must to combat your dementia risk.

Quick definition of aerobic exercise:

• Increases your heart rate and breathing over a sustained period (minimum of 10 minutes);

• Uses large muscle groups in a rhythmic and continuous manner eg cycling, brisk walking, rowing, swimming;

• Primarily depends on oxygen to generate energy during the activity (primarily from glucose and fat).

Benefit #1 – Boosts Brain Blood Flow and Oxygenation

As bipedal creatures, movement is life. Without the ability to move, our prospect of survival diminishes almost entirely. Without the tendency or willingness to move, a state of dis-ease will establish itself, and can represent in a vast number of ways based on your epigenetic profile (epi = environment, genetic = related to genes, DNA, heredity).

Regular movement improves all facets of our health, including brain health. A 2020 study by Thomas and colleagues discovered that twelve months of aerobic exercise increased cerebral blood flow in key memory regions (hippocampus and anterior cingulate cortex) and thus improved memory outcomes in older adults with mild cognitive impairment (average age 66.4 years). The same results were not seen in the same aged group that performed stretching only.

Another randomised study in 2021 by Tomoto et al followed a similar protocol, splitting older adults with mild cognitive impairment into an aerobic exercise and stretching only group for twelve months. It was discovered that aerobic training reduced arterial stiffness and consequently improved cerebral blood flow. Again, no such changes were measured in the stretching only group.

Whilst both of these studies investigated changes in older adults with already identified cognitive decline, the evidence points to the brain benefits of regular aerobic exercise. This is why exercise is such a great prophylactic, as its regular and recommended practice prevents or protects against disease, infection, and unwanted outcome.

 

Benefit #2 – Supports Neuroplasticity and Memory Function

Understanding how physical exercise influences brain function and cognition through the modulatory effects of brain-derived neurotrophic factor (BDNF) has been extensively studied over the past few decades.

BDNF is a protein that supports the survival, growth and function of neurons, acting as a key regulator in the brain. It’s a crucial player in neuroplasticity (the brain’s ability to change and adapt), which underlies learning and memory. Consequently, a reduction in BDNF levels is closely linked to deteriorating brain health (3). Side note: studies show reduced BDNF levels in depressive individuals. 

There is evidence-abounds that exercise improves cognition through developing BDNF levels in the brain. A significant increase in BDNF levels after exercise training has been reported for several weeks to one year, suggesting the potent effect of physical activity. This increase is more profound after aerobic exercise compared to other types of motor activity (4).

 

Benefit #3 – Reduces Inflammation & Lowers Chronic Disease Risk

One of exercises greatest claims to fame (and there are many) is the anti-inflammatory effect it has throughout our body. Chronic, systemic (something that affects the whole system) inflammation is a known risk factor for many diseases, including cardiovascular disease, type 2 diabetes, depression, and you guessed it…dementia.

When we engage in regular, consistent and age-appropriate physical activity, our body shifts from a pro-inflammatory state to an anti-inflammatory one. Exercise down-regulates inflammatory markers, reduces visceral fat (the fat surrounding our internal organs, which itself produces inflammatory substances), improves mitochondrial and metabolic health (click here to see my previous blog titled How to Improve Health & Longevity via Zone 2 Aerobic Training), and reduces psychological stress.

As we improve our insulin sensitivity and glucose regulation via regular movement, oxidative stress and inflammation (including neuroinflammation) is drawn down. A guaranteed way to achieve this is by elevating your heart rate for an extended period of time, aka aerobic exercise.

Conclusion

Recent studies reveal the effectiveness of long-term exercise in delaying the onset of physiological memory loss, which supports the positive effect of exercise as a non-invasive strategy against age-related memory deficits and neurodegeneration. The same evidence shows that sedentary and unhealthy lifestyles accelerate brain ageing, while regular physical activity, high cardiorespiratory fitness via aerobic exercise, or a combination of both, can mitigate cognitive impairment and reduce dementia risk (5).

At Restart, our organisational cause is to equip and empower our patients with the knowledge, tools and confidence to extend both their health-span (to improve quality of life now and into the future) and lifespan (to live a long and health-prosperous life). Developing consistent exercise strategies, whether you the reader are 35 years old or 85 years old, will have both immediate and long-term benefits!

If dementia onset is a concern for you, or you’ve noticed recent cognitive decline in a loved one, the best time to incorporate aerobic exercise into your daily routine is today. If this sounds too hard, or you’re not sure where to start, this is where we as a team of Exercise Physiologists can help.

Call 1300 899 757 to develop a personalised routine to combat your dementia risk.

Yours in exercise,

Luke

References

1. Thomas, B. P., Tarumi, T., Sheng, M., Tseng, B., Womack, K. B., Cullum, C. M., Rypma, B., Zhang, R., & Lu, H. (2020). Brain Perfusion Change in Patients with Mild Cognitive Impairment After 12 Months of Aerobic Exercise Training. Journal of Alzheimer’s Disease, 75(2), 617‑631. https://doi.org/10.3233/JAD‑190977

2. Tomoto, T., Liu, J., Tseng, B. Y., Pasha, E. P., Cardim, D., Tarumi, T., Hynan, L. S., Cullum, C. M., & Zhang, R. (2021). One‐Year Aerobic Exercise Reduced Carotid Arterial Stiffness and Increased Cerebral Blood Flow in Amnestic Mild Cognitive Impairment. Journal of Alzheimer’s Disease, 80(2), 841‑853. https://doi.org/10.3233/JAD‑201456

3. Romero Garavito A, Díaz Martínez V, Juárez Cortés E, Negrete Díaz JV, Montilla Rodríguez LM. Impact of physical exercise on the regulation of brain‑derived neurotrophic factor in people with neurodegenerative diseases. Frontiers in Neurology. 2024;15:1505879. doi:10.3389/fneur.2024.1505879

4. Experimental and clinical evidence of physical exercise on BDNF and cognitive function: A comprehensive review from molecular basis to therapy. Brain Behavior and Immunity Integrative, 3, 100017. Elsevier. 2023. https://doi.org/10.1016/j.bbii.2023.100017 ScienceDirect

5. Tari, A.R., Walker, T.L., Huuha, A.M., Sando, S.B., Wisløff, U., et al. (2025). Neuroprotective mechanisms of exercise and the importance of fitness for healthy brain ageing. The Lancet, 405(10325), pp.987–1002.