How does exercise heal the brain? Scientists seek answers
BY Karen Robock
13th Dec 2023 Wellbeing
3 min read
Scientists are digging into precisely why exercise holds so many benefits for our mental health and memory. The answer, studies say, lies in our brain chemistry
I’ve jogged through postpartum depression (twice), relied on Pilates classes to help me stretch during stressful times in life and I often go for a walk after a particularly bad day.
So it’s no surprise to me that there’s a link between exercise and mental health. But scientists have now made it official: research has found a direct connection between movement and mood.
Each time you work up a sweat, your body releases feel-good neurotransmitters, or “happy hormones,” including endorphins, dopamine and endocannabinoids, the latter being responsible for the so-called runner’s high.
Now researchers are also pointing to myokines—dubbed “hope molecules”—as an important contributor to the mental health benefits of exercise.
Myokines and your mood
When our muscles contract, chains of amino acids called myokines are released into the bloodstream; they help your muscles and organs communicate.
Researchers are looking into the effect of myokines on the brain. They think this communication increases resilience to stress, reduces symptoms of trauma and anxiety and have a direct effect on depression.
"Myokines reduce systemic inflammation, which is especially beneficial for people with drug-resistant depression"
A 2021 review published in Neuropharmacology showed evidence that myokines boost brain function (eg, improving memory and mood).
“Myokines reduce systemic inflammation, which is especially beneficial for people with drug-resistant depression whose low mood is linked to high inflammation,” explains Dr Jennifer Heisz, an expert in brain health and associate professor in the department of kinesiology at McMaster University in Canada.
Benefits of exercise on mental health and memory
Group exercise is an effective way to reduce loneliness
There’s also a growing body of research proving that exercise helps build key connections between the networks within the brain, too, improving overall cognitive performance.
Studies have shown that physical activity stimulates creativity, sharpens judgement skills and improves mental energy.
It can also help to slow age-related cognitive decline, possibly even stalling the onset of Alzheimer’s disease.
A new study published in the Journal for Alzheimer’s Disease Reports found that walking regularly (30 minutes a day four times a week) was enough to measurably improve memory, even in people who have already been diagnosed with mild cognitive impairment.
"Physical activity stimulates creativity, sharpens judgement skills and improves mental energy"
A recent study published in the British Journal of Sports Medicine showed that treatment for depression can be much more effective when physical activity is added to the usual care. Participants found benefits after 12 weeks of exercising for 30 to 60 minutes a day.
“While exercise is not a substitute for professional mental health treatment, physical activity can complement and enhance the effects of the treatment,” says lead researcher Ben Singh, a research fellow at the University of South Australia.
He says regular exercise in a group setting can boost self-esteem and decrease feelings of isolation and loneliness.
How much should you exercise for mental health?
Gentle laps of the pool are enough to reduce symptoms of depression
Whether you’re cycling, swimming, walking around your neighbourhood or doing yoga, getting sweaty is good for your body and mind. But how much activity is enough to maintain brain health?
Experts suggest that you aim for a minimum of ten to 30 minutes, three to five days each week.
“For reducing depression, research suggests that aerobic exercise is less about intensity and more about duration,” says Heisz.
Just ten minutes of light movement, like gentle laps in the pool or walking your dog, are enough to boost your mood, and the effects increase for every ten extra minutes that you move, for up to an hour.
"For reducing depression, research suggests that aerobic exercise is less about intensity and more about duration"
Exercising beyond 60 minutes didn’t provide extra mental health benefits, according to Singh’s study.
Strength-training, such as Pilates and lifting weights, does count toward your daily exercise goals (and is essential for strong bones). And research shows that increasing the intensity of resistance workouts by just ten per cent will yield a greater antidepressant effect.
“It is amazing to consider how moving our bodies can heal our minds,” says Heisz. To get the biggest overall health boost, the key is to zero in on sports and activities you enjoy, so you’ll keep going back to them.
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