What exercise can, and can’t, do for our mental health

Physical activity also pumps up more than our muscles.

It increases the size of the hippocampus, which relates to memory, and the insular cortex, which relates to emotional regulation.

The hypothesis is that if the structure is changing, the function is improving, Brinsley says.

Then there is the stimulation of neurotransmitters. Along with a boost in the mood-stabilising chemical, serotonin, exercise primes our motivation circuits via dopamine, which are depleted in people suffering depression.

The release of brain derived neurotrophic factor (BDNF) helps with neurogenesis, which is the creation and maintenance of cells in your brain, while higher levels of GABA, which has a calming effect, helps to decrease anxiety. “So your brain as an organ is healthier from exercise,” Brinsley explains.

What exercise cannot do for our mental health

Professor Anthony Hannan from the Florey Institute of Neuroscience and Mental Health in Melbourne says mental illness is complex and caused by a range of factors from genetic predisposition to environmental and lifestyle factors, factors, and their interactions throughout life.

“The beneficial effects of increased physical exercise have been shown in brain disorders such as depression and anxiety disorders,” Hannan says. “However, exercise is not a ‘cure all’.”

There is “substantial evidence” to support medication and psychotherapy, which should be continued according to a clinician’s advice. “However, the beauty of physical activity is that it can be combined with medical treatment or other lifestyle interventions,” Hannan says.

“Exercise is not going to help you in a crisis,” Brinsley adds. “It’s not the be-all and end-all and going to solve all your problems. It’s one ingredient in this recipe that is going to promote better mental health.”

How much do you need to do?

While the physical activity guidelines recommend 30 to 60 minutes of moderate intensity exercise at least five days a week, this can be unrealistic for anyone suffering depression and consequently lacks motivation and finds it hard to even get out of bed. When that is the case, Brinsley reminds that everything we do makes a difference:

“Something is better than nothing and 10 minutes a day gives you good mental health benefits.”

What kind of exercise is best for mental health?

To obtain the benefits of exercise, we have to do it regularly. For this reason, Hannan says the best kind of physical activity for our mental health is anything we enjoy, and can do safely. And there is evidence to support various kinds of activity.

“Walking is a very healthy activity, and when done in natural settings (e.g., ‘forest bathing’) can have added beneficial impacts on mental health,” Hannan says.

Research suggests aerobic exercise, like walking, running, cycling, has a similar effect as antidepressants, and it can help ward off depression too. A review, published in April, found that two and a half hours a week of brisk walking was related to 25 per cent lower risk for depression.

The researchers suggested this was because of inflammatory responses to activity and long-term changes to the brain. Additionally, improvements to self-esteem and body image can help social interactions and coping skills. Exercising, while having social interactions, can also enhance the positive effects, Hannan says:

“Social interaction is also good for the brain, so forms of physical activity that also involve social interaction can have added benefits.”

And while there is less research into resistance training, an increasing number of studies suggest that our mind grows stronger alongside our body. One 2018 study found resistance exercise “significantly reduced depressive symptoms” among research participants. Separate research, published in 2021, found preliminary evidence of improvements in prefrontal cortex white matter volume and executive functioning following resistance training. This is significant given white matter dysfunction is common in psychiatric conditions, including depression, stress- and anxiety-related disorders.

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Finally, mindful exercise like yoga or tai chi have benefits of their own.

“You’re typically taught to pay attention without judgement and have compassion towards yourself, whilst exercising,” Brinsley says. “You change the way you perceive a situation, yourself and your thoughts, and therefore you’ve allowed your nervous system to calm down, and you’ve allowed your body to change its state based on how you’re mentally thinking and feeling.”

Then there is the effect of our body doing movement which creates physiological changes that influence our brain and mental health. It makes exercise, especially when we apply mindfulness to it, a way to feel better both from the top-down and the bottom-up.

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