Exercise, Movement, and The Brain
New research reveals the health benefits of dancing
Posted November 30, 2015
Last month, I began a series of posts focusing on recent scientific research that supports the philosophical claims in my latest book, Why We Dance: A Philosophy of Bodily Becoming. In turn, I am interested in how the notion of "bodily becoming" illuminates the significance of these research findings, and suggest directions for further projects.
My last post took on the claim at the core of bodily becoming—I am the movement that is making me—teasing out examples from studies involving taxi drivers, ballet dancers, and robots. Today I look more closely at the relationship between bodily movement and the brain that this claim entails.
Studies of bodily movement and human health generally fall into two categories that reinforce one another: exercise studies and sitting studies. In general, exercise studies prove that exercise is good; sitting studies prove that sitting is bad. Even exceptions to these outcomes prove the rule. According to one recent study of women in England, for example, sitting for long stretches is not detrimental to your health if you fidget moderately or vigorously. On the other hand, other studies claim that exercising intensely for a short time does not counteract the detrimental effects of sitting for the rest of the time.
What emerges in the crossfire is a sense that bodily movement is the determining ingredient of health.
Let’s look further.
Health or fitness is often measured in terms of a body’s ability to metabolize oxygen. Oxygen, pulled into the lungs, pumped through the blood stream, enters every cell. Once there, it fuels the mitochondria within each cell that produce the energy that allows the cell to do its work. Exercise, studies show, increases the presence of oxygen within the body, the bloodstream, and the cell.
Exercise engages muscles. As muscle cells contract along the length of a muscle, the skeleton of a bodily self moves. These contractions not only help in pumping oxygenated blood through the circulatory system, they trigger a need for more oxygen, deeper breathing, a stronger pulse. They prime the respiratory and circulatory systems. By oxygenating the body in these ways, exercise—in addition to improving balance, strength, and coordination—lowers blood pressure, reduces cholesterol, decreases risk of obesity and diabetes, and generally improves cardiovascular health.
Until as recently as 1995, researchers believed that the health benefits of exercise were limited to “the body” as opposed to “the brain.” Now, however, the field has shifted. Not only is it clear that exercise primes brain cells with work-enabling oxygen, it is also evident that exercise actually catalyzes the growth of new brain cells (called neurogenesis) as well as the production of factors that aid in the creation of new synapses (called synaptic plasticity).
What is going on?
First a word about brains. In common parlance (thanks to Donald Hebb's 1949 coinage), brain cells that "fire together wire together," thereby creating new “synapses” or connections between one neuron and another.
In the moment of “firing,” an electrical impulse runs along the axon or branch of a brain cell to its tip. There it morphs into a neurotransmitter that leaps across the gap between one neuron’s axon and another’s receiving dendrite. These synapses represent something learned that may be remembered.
In this "wiring," then, the neuron branches don’t touch. They don’t “wire" in the sense of fusing. What connects the neurons is a trace of a movement made—a trace that exists as an “affinity” between neurons, a potential for an impulse from one cell to jump to the other again in the future.
In other words, anything humans learn exists as what I call a kinetic image. It does not exist as a physical structure, it “exists” only in the movement it enables, regardless of whether that movement results in a thought, an emotion, or an action.
From the perspective of bodily becoming, the brain is movement. It exists as a template for movement potentials between neurons. Each neuron is a capacity for sensing and responding to a nudge from another neuron. That is what it is.
Rather than fire and wire, it might be more accurate to say that the neurons pop and neurotransmitters hop.
What effect does exercise have on this kinetic process that underlies all of our learning and remembering, our highest abstractions and most concrete sensory awareness?
New findings and new qualifications on older findings appear every week. For example, scientists have found that exercise increases glutamate, a neurotransmitter responsible in 80% of brain signaling for stirring up the activity that enables the signaling leap.
Exercise also appears to increase the release of growth factors—especially BDNF (brain-derived neurotrophic factor)—that works by thickening axons and dendrites and spurring neurons to sprout new ones. In other words, the BDNF works by boosting the potential of neurons to pop and hop—not by building an actual “circuit” or “net.”
Exercise works within cells throughout a bodily self as well to produce proteins that travel into the brain to support the activity of both neurotransmitters and growth factors.
Further, a study just published on November 19 suggests that exercise boosts cell production of an enzyme (SIRT3) located within the mitochondria that protects the mitochondria’s all-important energy production from the kinds of stresses caused by neurotoxins and other factors.
In these ways, then, exercise creates conditions that enable brain cells to learn—where that learning, from the perspective of bodily becoming, is a rhythm of creating and becoming patterns of movement that find expression in thoughts, feelings, and ideas. Exercise serves as an engine, outlet, and enabling condition for the rhythms of bodily becoming.
Often these findings are summed up using the metaphor of “plasticity,” affirming that exercise spurs synaptic plasticity. This metaphor implies that the brain is a substance that is malleable, changing shape in response to external forces. However, once we adopt a perspective of bodily becoming the metaphor of plasticity falls short. Our brains are not passively being shaped; they are actively participating in the shaping. Our neurons are themselves reaching, grabbing, triggering, tossing, and in so doing, creating the very organism whose ongoing health they exist to serve—as the condition of their own survival!
It might be more helpful to think of the brain as an ongoing, reflexive rhythm of kinetic image creation.
Why, then, does exercise have such a profound effect on a human brain? The perspective of bodily becoming suggests a reason. Bodily movement is a cue for a brain to wake up. Bodily movement signals to the brain that there are decisions to make; opportunities to take; dangers to avoid, and pleasures to pursue. Bodily movement signals to the brain that it is time to come fully on line and do the job it exists to do: guiding conscious participation in the rhythms of bodily becoming.
What kind of bodily movement is best for boosting brain action? When asked the question, John Ratey, Associate Professor at Harvard Medical School points to activities that are aerobic and involve learning movement patterns. “The more complex the movements, the more complex the synaptic connections. And even though these circuits are created through movement, they can be recruited by other areas and used for thinking… The prefrontal cortex will co-opt the mental power of the physical skills and apply it to other situations” (56).
His analysis points to dance, and the perspective of bodily becoming illuminates the significance of doing so. Dance is not simply exercise. It is not simply bodily movement. Dance is the kind of exercise that requires the brain to do what it does when it is involved in any activity at all. It does not simply oxygenate the brain and enable the creation of connections; it challenges neurons to make new connections. It does not just spur the grown of new and better brain cells, it puts them to use, creating patterns of sensation and response that form the basis of all of our patterns of attention and action. Dancing exercises the self-creating rhythms that are who we are as brain cells, full bodily movements, and at every scale in between.
The practice of any dance form can do something else as well: it can serve to cultivate a sensory awareness of oneself as movement. It can encourage the creation of neural affinities that express the patterns of attention to bodily movement that the action of learning those movements requires. It thus can serve to help a bodily self learn to move in ways that unfold its potential to do so.
Exercise enhances the ability of a brain to make new connections, and dancing requires it. Dancing we create ourselves.
Cheng, A. "Mitochondrial SIRT3 mediates adaptive responses of neurons to exercise, and metabolic and excitatory challenges." November 19, 2015. Cell Metabolism. E-published Nov. 19, 2015.
Gareth Hagger-Johnson, Victoria Burley, Darren Greenwood, Janet E. Cade. 2015. “Sitting Time, Fidgeting, and All-Cause Mortality in the UK Women’s Cohort Study.” American Journal of Preventive Medicine.
Hannah, Judith Lynne. 2015. Dancing to Learn: The Brain's Cognition, Emotion, and Movement. Rowman & Littlefield.
LaMothe, Kimerer L. 2015. Why We Dance: A Philosophy of Bodily Becoming. Columbia University Press.
Ratey, John with Eric Hagerman. 2008. Spark: The Revolutionary New Science of Exercise and the Brain. New York: Little, Brown & Company.
Shaw, Jonathan. 2004. “The Deadliest Sin: From the survival of the fittest to staying fit to survive: scientist probe the benefits of exercise—and the dangers of sloth.” Harvard Magazine. 36-43, 98-9.
“The Health Hazards of Sitting,” Jan 20, 2014. Washington Post, https://www.washingtonpost.com/apps/g/page/national/the-health-hazards-…
First in the series: Recent Science Supporting "Why We Dance"