Exercise releases “hope molecules” into the bloodstream
BY Karen Robock
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.
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. 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.
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.
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 1
