Physical Activity & Mental Health: How Exercise Treats the Mind

Regular exercise does more than build muscle and improve cardiovascular health. It also transforms your brain chemistry in ways that can rival psychiatric medications—without the side effects.

Harvard psychiatrist John Ratey makes a compelling case for exercise as a treatment for mental health conditions. Drawing on neuroscience research, he shows how physical activity balances the brain chemicals that regulate mood, attention, and motivation. Keep reading to learn how this simple intervention can help manage stress, anxiety, depression, addiction, and ADHD.

The Link Between Physical Activity & Mental Health

John Ratey (Spark) contends that, for mental health, physical activity can be prescribed as a form of treatment. This diverges with another approach that has been dominant in the field of psychiatry since the 1980s—prescribing medications. This practice emerged with the idea that common mental disorders were due to chemical imbalances in the brain.

Reliance on medications was merely the latest in a series of ideas that prompted treatment strategies: In the era of eugenics (the belief that humans could be improved by selective breeding), poor mental health was seen as a product of genetically inferior brain anatomy. Lobotomies (removing parts of the brain) and forced sterilization (to weed out “bad genes” from the human gene pool) were preferred treatments. Later, in the Freudian era, psychologists believed that thoughts and behaviors came from the subconscious mind, and psychoanalysis became the preferred treatment.

The more recent pharmaceutical approach to treatment seeks to restore chemical balance in the brain, but even that approach has proven to be an incomplete treatment for most mental health issues. Some experts are even convinced that the rise of psychiatric medications has contributed to the prevalence of mental health illness today. They cite evidence indicating that the use of psychiatric drugs leads to chronic psychiatric disorders with more severe symptoms for many patients.

How It Works: Exercise Balances Neurotransmitters 

Using exercise as a treatment in the way Ratey describes seems to have none of these adverse effects, and, increasingly other clinicians also advocate using it this way. But what makes exercise so effective where other treatments have fallen short? Brad Stulberg (The Practice of Groundedness) writes that exercise affects mental health because your mind and body are connected. By staying physically active, you can boost your mood, increase your energy levels, and think more clearly and creatively.

Ratey, an Associate Clinical Professor of Psychiatry at Harvard Medical School, explains how this mind-body connection works. Neurotransmitters are chemicals that regulate the signals passing along the brain’s neural network. When there’s an imbalance of neurotransmitters we can experience difficulties such as anxiety, depression, scattered focus, memory loss, and more. Too much glutamate, for instance, leads to a signal overload that can cause excitotoxic stress. Too little gamma-aminobutyric acid (GABA) undercuts your brain’s ability to stop the signals. 

The functioning of these two neurotransmitters is further regulated by three other neurotransmitters you may have heard of: serotonin, norepinephrine, and dopamine. The messages that end up getting transmitted throughout the brain are largely regulated by these three chemicals. There’s overlap between their functions, but: 

• Serotonin is largely responsible for signals having to do with mood. 
• Norepinephrine influences attention and arousal. 
• Dopamine works in the realm of motivation.

These are the three chemicals targeted by most psychiatric medications. Selective serotonin reuptake inhibitors (SSRIs) such as Lexapro, for example, are used to regulate the disruptive mood states associated with depression by increasing serotonin levels in the brain. 

Ratey supports the use of such medications and is careful not to suggest that exercise should be relied on to the exclusion of drugs in particular cases. Such decisions are best made under the guidance of physicians familiar with the case. Nevertheless, Ratey argues that exercise helps to bring all these chemicals into balance by stimulating the release of each of these neurotransmitters in optimal amounts for mental health.

(Shortform note: Neuroscience research shows that regular exercise improves your mental health by releasing a host of brain chemicals including endorphins, endocannabinoids, and dopamine—all of which boost your mood.)

How Physical Activity Impacts 5 Mental Health Conditions

The neurotransmitter balance that exercise promotes isn’t just theoretical; it has practical implications for treating specific mental health conditions. Ratey demonstrates how the same mechanisms that regulate serotonin, dopamine, and norepinephrine can address a range of psychiatric challenges. Let’s examine how exercise works as a treatment for five common conditions: stress, anxiety, depression, addiction, and ADHD.

#1: Stress

To understand the benefits of exercise for stress relief, it’s important to understand what stress is in the first place. Ratey defines stress as anything that initiates activity at the level of our cells. By this definition, our environments present countless stressors. For example, when we move, we stress both our muscles and the brain cells involved in controlling that movement. When we eat vegetables such as eggplant, our cells activate as they work to process toxins the plant has created to protect itself. When we hear an unexpected noise, our brains initiate a stress response as they work to assess the source of the noise and whatever threat it might pose. 

(Shortform note: Another biological understanding of stress is that it’s anything that threatens homeostasis. Homeostasis is a state in which the body’s physical systems are in balance. So anything that disrupts that maintenance is a stressor.) 

Under this narrow, biological definition, stress is neither inherently good or bad; it’s a fundamental biological process. If the body can handle the effects of the stress—for example, if cells can clean up the waste produced by oxidative stress—then the stress won’t have negative effects at the cellular level. It’s when the body can’t keep up with the cellular effects of stress that it starts to feel negative effects. When that happens, we end up feeling stressed, which Ratey explains is a psychological and emotional reaction to cellular stress events. 

(Shortform note: Some experts take a different view of just how stress is neither good nor bad. Defining it as a psychological challenge, they observe that people who seem to handle stress well are motivated by it—seeing it as an opportunity to rise to a challenge. By contrast, those who don’t handle stress well are demotivated by such a challenge. These experts suggest that cognitive reframing (thinking of the stressor differently) can help to make stress work for you.) 

Given the risks associated with chronic stress, it’s important to understand how exercise can be used to limit our exposure to its negative effects. 

Exercise Calms Our Mind & Body

Exercise stimulates the release of proteins that grow and strengthen the neural network: BDNF, VEGF, and FGF-2. This reduces the likelihood that our brains will misperceive threats or lose control of the body’s stress-response system. Beyond this, Ratey argues, exercise counteracts the disempowering effect stress and fear has on your mind. As an activity you voluntarily pursue, it’s empowering, which reinforces a positive feedback loop that bolsters your resistance to the stressors of life. 

Exercise Is a Mild Stress

Ratey contends that exercise, as a form of mild acute stress, is like an inoculant that builds resilience, toning all the machinery of the brain and body and tamping down our trigger-happy stress response system. He points out that this effect is largely a consequence of the way our cells recover after exercise-induced stress—this is part of the activity and recovery process of the body’s stress response. In addition to this recovery mechanism, the broader effects of exercise on the brain condition us to handle stress better. 

#2: Anxiety

As mentioned in the galanin study above, stress-related disorders include anxiety and depression. Anxiety is a component of your brain’s stress-response system; it’s a natural response to legitimate threats. When it becomes overly heightened, turning into an undue fear response to misperceived threats, it becomes a disorder. According to Ratey, exercise alleviates both the symptoms and the state of anxiety by calming our bodies, increasing our sense of autonomy, and retraining our brains to better regulate and reduce fear signals. 

#3: Depression

While anxiety represents an overactive threat response, depression manifests as the opposite problem—a shutdown of the brain’s communication systems. Ratey argues that depression should be thought of as a breakdown in neural communication. In the depressed brain, the neural network breaks down, disconnecting brain regions from one another. This causes critical parts of the brain to atrophy. A lack of neurotransmitters compounds this state leaving the brain unable to kickstart its attention and motivation tools. The effects of exercise can break this vicious circle by rebuilding neural connections, restoring healthy brain chemistry, powering neurogenesis, and nurturing a sense of hope.

#4: Addiction

Both anxiety and depression entail disruptions to neurotransmitter balance, but addiction represents a more extreme hijacking of the brain’s reward system. Ratey explains that addiction co-opts our attention resources by making the brain focus exclusively on the object of addiction. For the drug addict, for instance, an overload of dopamine in the brain—triggered by the drug of choice—tricks the brain into attending only to that trigger as if it’s a matter of life or death. Exercise breaks this fixation by retraining the brain’s motivation system—weaning it off an unnatural dopamine fix in favor of a balance of healthy neurochemicals.

(Shortform note: Substance abuse and addiction are common markers of trauma. Bessel van der Kolk discusses the unique nature of traumatic memories in The Body Keeps the Score. Such memories alter the makeup of the brain itself and often leave the victim feeling fearful and powerless. A key aspect of Ratey’s insights on exercise and addiction is that exercise can give us a sense of accomplishment that helps to overcome this powerless feeling.)

#5: ADHD

Like addiction, ADHD involves dysregulation of dopamine—but in the opposite direction. Rather than dopamine overload fixating attention, ADHD involves insufficient dopamine that scatters it. Ratey argues that people with ADHD have functional but poorly regulated attention systems in the brain. This is caused by low levels of dopamine and norepinephrine in the ADHD brain, which undermine its ability to prioritize among distractions, sustain motivation, and combat impulses. Exercise causes brain cells to secrete these key neurotransmitters, builds coordination between the brain’s attention resources, and conditions the systems that support continued attention regulation. In particular, exercises requiring some structure, risk, or coordination (for example, martial arts) seem to be especially effective in harnessing the attention resources of the ADHD brain.

Explore Further

To better understand the connection between physical activity and mental health, read Shortform’s comprehensive guide to Ratey’s book Spark. You’ll learn more about the mind-body connection and how exercise optimizes brain function in support of mental wellness.