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With all the noise about the importance of diet and sleep, meditation and stress management for better brain health, have you ever wondered whether there is ONE best thing to keep your brain and thinking smart and sharp?

Yes. It’s called exercise.

And here’s the problem. It appears a significant proportion of the population are either allergic or intolerant to this activity. For some, the mere thought of donning activewear to wear to the gym can bring them out in hives.

I understand. Not everyone loves the idea of all that hot sweaty work, and of course it’s not something you can get away with doing occasionally, because the expectation is that this is a daily activity.

Exercise matters big time. It’s up to each and every one of us to find a way to incorporate more physical activity into our lives to be healthier, happier and smarter thinkers.

But, don’t just take my word for it.

The new WHO Guidelines recommend specific interventions for reducing cognitive decline and dementia and guess what is listed first.

You guessed it. Regular exercise.

What this looks like is:

Age 5-17 years 60 minutes of moderate to vigorous activity EVERY day

Age 18-64 years Minimum of 150 minutes of moderate intensity aerobic activity PER WEEK PLUS two sessions of strength or resistance exercise/week

Age 65 and beyond. As above depending on physical health and capability and including activities to improve balance.

Why exercise

Escaping from our predators by running away fast has been a distinct evolutionary advantage. Little wonder our brain development has been closely tied to our ability to move quickly.

Historically the ancient Greeks trained in open-air “gymnasiums” to improve their military skills and body aesthetics. Yes, building the body beautiful started a long time ago.  But this was for men. It wasn’t until Jane Fonda and others introduced aerobics and jazzercize in the ’70s and ’80s that women became more involved in the fitness revolution.

Today exercise matters to combat our increasingly sedentary lifestyle which is contributing to a number of problems and costing us dearly.

1. The health cost to our physical and mental wellbeing.

Lack of exercise is associated with an increased risk of obesity and heart disease.

It compromises our mental wellbeing from higher stress levels, lower emotional regulation and reduced mood enhancing hormones.

Being sufficiently physically active boosts cerebral blood flow bringing additional oxygen and nutrients to our ever energy-hungry neurons and stimulates the production of intracellular mitochondria important for energy production in the muscles and brain.

In addition, it promotes the release of neurotransmitters including BDNF and growth factors needed to maintain our neurons in a state of good health and repair, and boost our capacity to think well, learn more and remember what’s important.

When we undertake regular activity higher levels of BDNF (Brain Derived Neurotrophic Factor) also stimulates the process of neurogenesis – the production of new neurons. BDNF along with the hormone Irisin (produced during endurance exercise) have a neuroprotective effect.

As Professor Ken Nosaka reminds us

“Exercise is Medicine”

2. The happiness cost.

In times of severe stress, anxiety or depression, high levels of the stress hormone cortisol become neurotoxic, damaging existing synaptic connections between neurons, and reducing neuroplasticity leading to loss of neurons in the hippocampus – the part of the brain associated with learning and memory.

This is where we can use physical activity to burn off some of our stress and boost our natural mood enhancing hormones including Dopamine (part of the brain’s reward circuitry), Serotonin ( important to self-esteem and confidence), GABA (that helps induce calm and reduce anxiety) and Endorphins (produced under intense exercise to boosting endurance).

3. The cognitive cost to smarter, sharper thinking.

We think better on our feet.

Exercise matters because your level of physical activity at every age will have an impact on your future cognitive ability. Kids who exercise regularly do better in the classroom and young adults with a higher level of cardio fitness have been shown to have better cognitive function with faster speed of mental processing and verbal memory when they reach midlife (age 43- 55).

How this works is that exercise modulates our genes leading to structural and functional changes in the brain, protecting us from neurodegeneration or cognitive decline.

4. The economic cost.

The first study to examine the global economic cost of physical inactivity in 2013 put this at around US$67 billion. The bill to the Australian economy then was over $805 million.

Can any of us afford NOT to be more physically active?

The new exercise prescription: MOVE MORE, SIT LESS

Managing exercise intolerance.

If the thought of exercise is as appealing as choosing to sleep naked on a bed of nails, fear not help is at hand.

1. Stand up.

If your job requires you to be on your feet for a number of hours during the day you’re already working with an advantage. If you’re mostly desk-bound, look for discretionary opportunities to move more. This might take the form of a stand -up or variable height desk, making meetings a time for standing or walking or choosing to get up, stretch your legs and go for a brief walk for five minutes at least once an hour. Aim to stand for around two hours of your working day working towards four hours if you can manage it.

2. Sit less.

Walking for an hour every day can cancel out the negative impact of sitting at a desk all day. The average Briton sits for 8.9 hours per day. How long do YOU sit for?

Prolonged sitting (>8 hours/day) is associated with a 60% higher risk of premature death. (Help!) Now, is the time to get off your bottom, find your trainers and start pounding the pavement, the park or the beach. What nicer way to start or finish your day with time out (preferably in nature) with a walk that’s doing your body, mind and brain a power of good?

3. Just Move.

If the gym doesn’t do it for you, do something else. Dancing, walking, skipping, whatever takes your fancy. Household and gardening activities count as well. If the grass needs cutting, now is a good time to get the lawnmower out.

4. Get a little bit eccentric.

Conventional exercise gets us to exercise our muscles in a concentric fashion shortening the muscle under load. An example here would be a biceps curl. The eccentric version is the opposite. Here you start with your arm flexed then slowly extend the arm to full extension against resistance.

This has been shown to be beneficial for a number of health benefits including increased muscle mass, improved balance and flexibility, improved blood lipid profile and insulin sensitivity and better still it’s believed to improve cognitive functioning. For one thing, you have to focus harder when doing eccentric exercise. Getting eccentric is as easy as choosing to sit down slowly in a controlled manner or walking down the stairs.

5. Use a fitness tracker.

You might have a love-hate relationship with fitness trackers, but they are very good at raising awareness of how truly active we are. The suggested number of steps/days for good health is 10,000. If you’re only managing 2500-3000 steps a day, you know there’s room for improvement. Remember there’s nothing magic about that number and it’s important to note the 10,000 steps is the MINIMUM.

When it comes to brain power, ALL physical activity counts.

While 30 minutes of aerobic exercise remains the gold standard to aspire to, it’s the amount of additional discretionary activity that helps keep us on our toes when we’re thinking, learning and making those important decisions.

That’s smarter, sharper thinking at work.

Dr Jenny Brockis

Dr Jenny Brockis is a medical practitioner and internationally board-certified lifestyle medicine physician, workplace health and wellbeing consultant, podcaster, keynote speaker and best-selling author. Her new book 'Thriving Mind: How to Cultivate a Good Life' (Wiley) is available online and at all good bookstores.


  • julienne says:

    Thankyou very much for your email and information I have just been for a walk with Toto my jack Russell and I feel a lot better for it I have a very active dog that keeps me walking morning and evening and sometimes in between
    He is well known in the neighbourhood and is a very social dog so that benefit s me as well

    • Dr Jenny Brockis says:

      Dog walking is not just good for the dog it’s great for us too for the very reasons you’ve suggested.

  • Julie says:

    Hi Jenny I have fibromyalgia and chronic pain and keeping active physically and socially and mentally keeping me going.
    I’m also active in my church in mount hawthorn community and in my local area in Maylands
    With a grant from connect groups for a support group that I named true blue support group voted most popular name I have a scholarship as well from connect groups in group work facilitator training

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