Leg day for your brain: The surprising link between muscle power and brain power
Muscle strength and fitness are key to brain health and cognitive function, especially as we age. Credit: Dr O O'Neill, Wikicommons.
Muscle strength a key to brain health?
Forget sudoku – your next brain training session might be at the gym. Recent research suggests that the key to maintaining cognitive sharpness as we age could be hiding in our leg muscles.
In one groundbreaking study that followed 324 healthy female twins with average age of 55 years over a decade, researchers at King's College London found that those with more powerful legs at the start of the study showed significantly less brain ageing 10 years later.
The results held true even when controlling for factors like genetics and lifestyle, suggesting a direct link between muscle power and brain health.
Of course, despite the study being longitudinal in design - following the twins for a decade - it cannot be ruled out that it was the retention of cognitive function that then helped to keep the women healthy and therefore to maintain their leg strength.
But it is well known that exercise interventions strongly affect the brain, as shown directly using MRI imaging. So, the most likely scenario is that any interventions (exercise, diet, etc.) that improve, or at least maintain, leg muscle power also improve cognitive function in older adults.
Training the legs, or any other body part, might just be a key to training the brain.
Strengthening the legs might be a key to maintaining brain health and cognitive function into older age.
Credit: Alora Griffiths on Unsplash.
The Power of the Pump
So, what's going on here? How can leg muscles influence our grey matter? The answer, it seems, lies in the way exercise affects our brains at multiple levels.
First, there's the oxygen factor. Recent research using a novel imaging technique called Green enhanced Nano-lantern (GeNL) has revealed that exercise significantly reduces the occurrence of "hypoxic pockets" – transient, localised areas of low oxygen – in the brain.
These hypoxic pockets could potentially be harmful to brain cells, so by reducing their frequency, exercise may be protecting our neurones from damage.
But it's not just about oxygen. Physical activity also promotes neuroplasticity – the brain's ability to form new connections and adapt to new experiences. Exercise has been shown to:
Boost production of new neurones in the hippocampus, our memory centre
Improve the strength of connections between existing neurones
Modulate important neurotransmitter (signalling) systems involved in learning and memory
Increase overall brain volume and improve white matter (nerve cell) integrity
It's like a full-body workout for your brain. Exercise doesn't just affect one aspect of brain health – it seems to benefit the entire system.
Exercise can trigger the growth of new neurones in the hippocampus - shown in green - the brain's memory centre. This may be one reason exercise helps maintain memory and stave off dementias with ageing. Credit: Danielsabinasz, Wikicommons.
More Than Just a Mood Boost
The benefits of exercise extend beyond just cognitive function. A recent expert review of 97 systematic reviews with meta-analysis (that is, a synthesis of the largest statistical reviews of the area), encompassing over 128,000 participants, found that physical activity consistently improved symptoms of depression, anxiety, and psychological distress across various populations.
The robustness of the effect was quite surprising, and the results clearly suggest that whether you're a healthy adult, someone with a chronic illness, or dealing with a mental health disorder, exercise may offer significant psychological benefits.
The mechanisms behind these mood-boosting effects are complex, and potentially involve:
Improved cardiovascular health
Changes in the immune system
Alterations in hormone levels
Increased production of neurotrophic factors (proteins that support neurone growth and survival)
Regardless of the mechanism, exercise is now a well-accepted, first-line treatment for mood disorders and should be a primary intervention for anyone who is able to participate in physical activities, in addition to any other medical treatments that might be suggested by your physician.
Physical activity is a great way to boost your mood.
Tailoring Your Brain-Boosting Workout
Before you dust off your trainers, it's worth noting that not all exercise is created equal when it comes to brain health. The current evidence suggests:
1. Intensity matters: Higher-intensity workouts seem to offer greater cognitive and mood benefits, although lower-intensity exercise, especially when performed outdoors, also has a great effect.
2. Mix it up: A combination of aerobic exercise, strength training, and balance exercises provides the most comprehensive brain boost.
3. Consistency is key: While even short-term exercise interventions show benefits, long-term, regular physical activity is likely necessary for sustained cognitive health.
4. It's never too late: Studies have shown cognitive benefits of exercise in older adults, even those with existing cognitive impairments.
The great thing about these findings is that they're actionable. You don't need expensive equipment or a gym membership to get started. Simple changes like taking the stairs instead of the lift or walking to the shops can make a real difference.
Higher intensities of exercise seem to offer the greatest cognitive and mood benefits for most people. But this might just mean taking the stairs when you get the chance. Credit: vecteezy.
A Step Towards Better Brain Health Policy?
The growing evidence linking physical activity to brain health has caught the attention of public health experts. Some are calling for a shift in how we approach cognitive health in ageing populations.
There is a clear need to move beyond just treating cognitive decline once it occurs. The current evidence strongly suggests we can delay, or possibly prevent, cognitive ageing through targeted exercise programs.
Some proposed initiatives include:
Integrating structured exercise programs into daily routines for older adults
Educating communities about the brain health benefits of physical activity
Designing urban environments that encourage regular physical activity
Looking to the Future
While the current evidence is promising, it should be stressed that there's still much to learn. Future studies are needed to explore:
The optimal types and intensities of exercise for cognitive health at different life stages
The effects of exercise on brain oxygenation in various disease models, such as dementia or stroke
The integration of new brain imaging techniques for a more comprehensive understanding of how exercise affects the brain
As research continues, one thing is clear: when it comes to keeping our brains sharp as we age, we might need to focus less on mental gymnastics and more on actual gymnastics – or at least a good leg workout.
So, the next time you're debating whether to take the lift or the stairs, remember: your future self's brain might thank you for choosing the climb.
It turns out that leg day isn't just for bodybuilders – it might just be the key to a healthier, happier brain for all of us.