Exercise Benefits the Brain – But How?

If you’ve been following any of my outreach, whether books, blogs, PBS specials or YouTube videos, it’s obvious that I have been hammering home the idea that physical exercise benefits the brain. This notion has been validated for many years with studies showing strong correlations between exercise and preservation of brain function as well as reduced risk for Alzheimer’s disease.

But I would suspect that many people have wondered why this happens? What is actually going on that connects exercise to these downstream effects?

In a recent study appearing in the journal, Neuropharmacology, Brazilian researchers explored this question in a paper entitled, How does the skeletal muscle communicate with the brain in health and disease?

They revealed that, when challenged by exercise, skeletal muscle releases a variety of chemicals called “myokines” that actively and positively influence brain health and function. And since muscle tissue secretes chemicals that circulate and influence another organ, the authors, rightly, now classify muscle as an endocrine organ, right along with other organs behave like this including the thyroid gland and the pancreas. Now that’s certainly a new consideration as it relates to muscle.

Further, the effects of these chemicals are not limited to the brain, as they influence the function of the liver, pancreas, bone, and even adipose tissue.

We’ve known that various products of muscle metabolism like lactate and ketone bodies are involved in muscle-to-brain communication. And research now reveals an entire suite of chemicals that muscle cells release that affect the health and functionality of the brain, like interleukin-6, cathepsin-B and BDNF. Their positive effects on the brain include increased growth of blood vessels, nerves and synapses, as well as improved executive function, memory and mood.

The authors of this fascinating report conclude by describing not only how their discovery may explain how lack of muscular activity (sedentary lifestyle) may predispose to brain decline, but, on a more positive note, how exercise may represent an important approach for brain disease treatment and prevention, stating:

In summary, several candidate molecules have now been proposed to mediate muscle-brain communication thereby representing powerful alternatives for the prevention or treatment of neurological disorders. Most of these candidates have emerged from studies investigating the endocrine mechanisms of physical exercise. Nonetheless, it is conceivable that proper muscle-to-brain signaling is an essential physiological mechanism that, once disrupted, may contribute to defective endocrine communication, and predispose individuals for brain disease.

Yes, exercise benefits the brain – your brain. And now we have a much better understanding as to how this happens. So next time you are walking or on your bike or lifting weights, imagine how your muscles are sending powerful chemical signals to nurture and protect your brain. It just may be the impetus you need to ramp things up a notch.