Why Are Myokines Called ‘Hope Molecules’?

Previously, endorphins have been the star of the show for the connection between exercise and mood: A great sweat session will cause a release of endorphins, that are neurochemicals produced within the pituitary gland that react with opiate receptors, meaning they make you are feeling really good. Figuring out also stimulates the production of serotonin and norphenylephrine, that are other happiness, wellbeing, and pleasure-inducing neurotransmitters.

These mood-boosting stimulations would probably be enough to offer you that post-yoga glow. But there’s something much more happening.

Researchers have come to know that when our muscles contract, they produce substances that get dispersed throughout the body. A few of these are chains of amino acids called myokines, and they can cross the blood-brain barrier—which implies they’ll act in your brain. And after they get there, they improve brain function.

“Several myokines—irisin, hydroxybutyrate, etc.—have been shown to stimulate neuronal function and facilitate synapses, that are the way in which neurons communicate with one another,” Mychael Vinicius Lourenco, PhD, an assistant professor of neuroscience on the Federal University of Rio de Janeiro, who co-authored a recent review of research around myokines and brain function, previously told Well+Good.

That features potentially “mediating the useful actions of physical exertion within the brain,” Lourenco and his co-authors write within the review. As a possible example, assisting with neuron communication could mean that myokines are helping those feel-good messages being sent by endorphins, serotonin, and norphenylephrine be heard.

Beyond just helping your brain do its job higher, researchers also think that myokines could actually be a bulwark against depression. This has led to the substances garnering the name “hope molecules.”

In 2016, physical therapy and psychiatry researchers writing within the journal Physical Therapy were reviewing research on the connection between exercise and depression. They referenced a 2014 study on mice during which mice with lower levels of a certain sort of myokine exhibit less resilience under stress than those mice with higher levels of the myokine.

“After a big amount of stress, the mice appeared to ‘lose hope,’ as evidenced by their decreased survival efforts during forced swimming (an indicator of depression),” the authors write. “Altogether, these results suggest that the discharge of ‘hope molecules’ from the skeletal muscles of rodents influence mood disorder symptoms.”

While we won’t necessarily extrapolate the findings from studies on mice to humans, each species share some underlying biology that may cause myokines to work in an identical way. Namely, these myokines could inhibit a neurotransmitter pathway that, when it’s overactive, is linked with depression.

This was compelling enough for Stanford University psychologist Kelly McGonigal, the writer of The Joy of Movement, to take notice of the study, and popularize the term. “Hope molecules,” McGonigal previously said on the Wealthy Roll podcast, may very well be like “an intravenous dose of hope.”

“It is not just an endorphin rush,” McGonigal says on the podcast. “You go for a walk or a run otherwise you lift weights and your muscles contract they usually secrete these proteins into your bloodstream. They travel to your brain, they cross the blood-brain barrier. And in your brain, they’ll act as an antidepressant. Like irisin [a myokine] could make your brain more resilient to emphasize. They increase motivation. They assist you learn from experience. And the one way you get these chemicals is by utilizing your muscles.”

Even when research continues to be developing for the way exactly exercise boosts mood and mental health, the link between exercise and wellbeing has never been clearer. Two recent meta-analyses on the results of exercise in adults and exercise in kids have found it to be an efficient bulwark against depression.

What with our emerging understanding of myokines, and the undeniable advantages of exercise, there’s never been a more compelling reason to take your medicine: A dose of movement.