Move Your Body, Protect Your Brain

Why exercise may be one of the most powerful tools we have against neurological disease

The relationship between physical activity and brain health is one of the most compelling areas in neuroscience today – and the evidence is growing stronger.

The 2024 Lancet Commission on Dementia Prevention identified 14 modifiable risk factors that together account for approximately 45 per cent of dementia cases worldwide. Physical inactivity is among them. What we do with our bodies today shapes the health of our brains tomorrow. 

How exercise protects the brain

At a biological level, exercise increases blood flow to the brain, helping deliver oxygen and nutrients to brain tissue. Physical activity also stimulates the release of brain-derived neurotrophic factor (BDNF), a protein that supports the growth and survival of brain cells and helps strengthen neural connections involved in learning and memory.

Exercise also benefits brain health indirectly by improving cardiovascular function, reducing inflammation, supporting healthy sleep, and helping regulate stress hormones such as cortisol. Together, these effects may help preserve cognitive function as we age.

Importantly, the threshold for benefit may be lower than many people assume. For those unable to meet moderate-to-vigorous activity targets, simply increasing low-intensity movement, such as walking or reducing long periods of sitting, has also been associated with a lower risk of cognitive decline and dementia. Some movement is far better than none.

Key research insights

Exercise and long-term brain protection

Groundbreaking research from the University of Queensland found that in adults aged 65 to 85, just six months of high-intensity interval training (HIIT) improved cognitive function – with benefits still measurable up to five years later. Exercise doesn’t just deliver short-term gains; it may build lasting resilience in the brain. 

Can exercise actually change brain structure?

After age 40, the brain naturally shrinks by around five per cent per decade. But research suggests this isn’t entirely inevitable. A landmark randomised controlled trial of 120 older adults found that aerobic exercise increased the size of the anterior hippocampus (a region critical for memory) by five per cent, effectively reversing one to two years of age-related brain volume loss. 

Reducing the risk of falls

For older adults, exercise offers another underappreciated benefit: fall prevention. Falls are the leading cause of traumatic brain injury in older adults, which is detrimental to brain health. Balance and strength training improves postural control, gait stability, and neuromuscular coordination. Activities like Tai Chi enhance muscle control and reaction times, while aerobic exercise supports the spatial awareness and decision-making needed to navigate everyday environments safely.

The mental health connection

Regular physical activity also has meaningful antidepressant effects. Long-term studies suggest that meeting recommended activity levels may reduce the risk of developing depression by up to 23 per cent – significant, because depression itself is a known risk factor for dementia. It also promotes the release of endorphins (specifically beta-endorphin), improving mood and reducing pain.

How much physical activity should you do?

Australian Government guidelines recommend that adults aged 18–64 aim for:

• At least 150 to 300 minutes of moderate-intensity physical activity each week, or
• 75 to 150 minutes of vigorous-intensity activity, or
• A combination of both

Adults are also encouraged to include muscle-strengthening activities on at least two days each week, and to minimise prolonged sitting where possible.

That works out to around 30 minutes of movement on most days – and it all counts. 

The best exercise is the one you’ll actually do

While experts recommend a mix of aerobic, strength, balance, and coordination exercises for optimal benefit, the most important principle is consistency. Whether it’s swimming, dancing, gardening, or simply going for a daily walk, the best exercise is the one you enjoy enough to keep doing.

For those living with or caring for someone with neurological disease, this is an area where small, sustained changes can make a meaningful difference – not just to physical health, but to quality of life, independence, and cognitive resilience.

References:

1. G Livingston et al, 2024, Dementia prevention, intervention, and care: 2024 report of the Lancet standing Commission, The Lancet.
2. D Blackmore et al, 2024. Long-Term Improvement in Hippocampal-Dependent Learning Ability in Healthy, Aged Individuals Following High Intensity Interval Training, Aging and Disease.
3. Mikel Izquierdo, 2025. Exercise for dementia prevention: Evidence for a flexible prescription, The Journal of Prevention of Alzheimer’s Disease.
4. K Erikson, 2011. Effects of aerobic exercise on hippocampal volume in humans: a systematic review and meta-analysis, Neuroscience.
5. J Firth et al, 2018. Effects of aerobic exercise on hippocampal volume in humans: a systematic review and meta-analysis, NeuroImage.
6. Y Zhong et all, Nov 2024. Mechanism-Driven Strategies for Reducing Fall Risk in the Elderly: A Multidisciplinary Review of Exercise Interventions, Healthcare.