KEY POINTS

  • Muscle tissue communicates directly with the brain and other organs through chemicals called myokines.
  • Through these chemical interactions between muscles and the mind, exercise improves cognitive function and mental health.
  • The brain is designed for movement. This is why inactivity breeds depression and cognitive decline while exercise fuels well-being.
If you somehow possess a superhuman imagination capable of conceiving of this cellular cacophony, you may entertain a question: what powers all this? Remarkably, the enormous energy required to run your cells ultimately comes from the oxygen you breathe and the food you consume. The latter seems important to remember the next time you don't feel like eating your vegetables. Digested to the smallest denominator, nutrients are converted by mitochondria—arguably the VIP citizens of your cells—into billions of adenosine triphosphate (ATP) molecules per minute. Although even an ordinary cell may house thousands of these energy-producing mitochondria, muscle cells are mitochondrial beehives, possessing tens or even hundreds of thousands to power their operations. Once made, ATP is feasted upon by your cells like exhausted runners devouring PowerBars at the finish line of the Boston Marathon.
Emerging almost impossibly from this molecular mayhem is you. Every thought, feeling, and action results from and depends on this unceasing cycle of energy demand and energy production. And if it isn't apparent from this description, the better your cells function at the level of the little, the better you feel and function at the level of the large.
This brings us back to resistance training. Given the vital roles your muscles play in energy production and brain function, perhaps it is time to begin appreciating resistance training and muscle building as being useful for more than athletes and magazine models. Using your muscles against resistance, for example, is far more effective for strengthening your bones than any calcium supplement (4). Regular muscle activity also improves insulin resistance (the cause of diabetes and many other metabolic conditions) better than any prescription medicine.
And now we know that stimulating muscle tissue with resistance training has emotional effects rivaling those of conventional antidepressants and psychotherapies (3). Recent neuroscience suggests that we evolved brains for one primary reason: to move (5). Counterintuitive to our traditional preoccupation with thinking, the primary function of the human brain is to coordinate complex movement (this is probably why we have brains while giant but stationary redwood trees do not).
Recognizing this intimate connection between the brain and movement, the biological basis of the mind-muscle relationship becomes clear, and the importance of resistance training for optimal physical and emotional health becomes indisputable.
Thomas Rutledge
Source: Thomas Rutledge
LinkedIn image: Dragon Images/Shutterstock. Facebook image: Robert Przybysz/Shutterstock

References

1. Pedersen, B. K., Steensberg, A., Fischer, C., Keller, C., Keller, P., Plomgaard, P., et al. (2003). Searching for the exercise factor: is IL-6 a candidate? J. Muscle Res. Cell Motil. 24, 113–119. doi: 10.1023/A:1026070911202
2. Severinsen MCK, Pedersen BK. Muscle-Organ Crosstalk: The Emerging Roles of Myokines. Endocr Rev. 2020 Aug 1;41(4):594–609. doi: 10.1210/endrev/bnaa016. Erratum in: Endocr Rev. 2021 Jan 28;42(1):97-99. PMID: 32393961; PMCID: PMC7288608.
3. Gordon BR, McDowell CP, Hallgren M, Meyer JD, Lyons M, Herring MP. Association of Efficacy of Resistance Exercise Training With Depressive Symptoms: Meta-analysis and Meta-regression Analysis of Randomized Clinical Trials. JAMA Psychiatry. 2018 Jun 1;75(6):566-576. doi: 10.1001/jamapsychiatry.2018.0572. PMID: 29800984; PMCID: PMC6137526.

About the Author

Thomas Rutledge, Ph.D., is a Professor-in-Residence in the Department of Psychiatry at UC San Diego and a staff psychologist at the VA San Diego Healthcare System.