COVID-19, Stress, and the Understated Benefits of Physical Activity
While public health experts and some state governors advocate for individuals to stay inside and self-isolate, the current COVID-19 epidemic is highlighting the effects that isolation has on an individual. Individualized separation, combined with a reified perception of COVID-19’s danger and the anxiety of processing new information every day, causes chronic stress and is associated with a burden on mental health, which increases risk factors for anxiety and depression . Further, it is well-established that stress is a powerful modulator of immunity, so stress directly influences the probability of infection .
Also, chronic stress causes structural and functional changes in the brain, resulting in modified social behaviors, which further limit an individual’s ability to cope with his or her stressful conditions through the epidemic . A 2015 study published in Nature, perhaps the world’s most acclaimed science journal, titled “Stress and the social brain: behavioral effects and neurobiological mechanisms” investigated stress’ effects on brain neurology . The researchers noted that “the effects of stress on social behavior depend on the timing, the duration, and the type of stress exposure.” In humans, stress promotes prosocial behaviors [behaviors that benefit others rather than oneself] towards ingroup members [members of one’s social group], and these positive social interactions can help protect someone from adverse effects of stress . However, isolation hinders this natural stress coping mechanism and instead causes an adverse positive feedback loop that progressively impairs the immune system.
Consider the following example: Sally is concerned about getting COVID-19, and being the diligent citizen she believes she is, listens to her governor and self-isolates in her apartment, only goes out once a week to shop for groceries, wears a mask when she is out and limits her social interaction with her friends. Months go by, and Sally keeps this up. In the meantime, she is slowly engulfed in stressful media discussing the “killer” virus and shattered political landscape. Sally begins to feel stressed, but because she is fearful about the illness, she continues to be a good citizen and limits her social interaction. Additional factors that increase Sally’s stress are her financial health (she lost her job), educational uncertainty (she doesn’t know if the school will be online or in-person), lack of a religious circle (since churches are closed but funerals and protests can happen), and a possible substance abuse problem. This heightened stress impairs Sally’s immune system, which puts her at a higher risk for COVID-19. Still, Sally is human, and humans need social interaction to naturally help lower stress, but she can’t. Sally will be a good citizen.
What I have presented is a not-to-far-off hypothetical that is strikingly similar to the lives of many Americans today. Plus, these adverse effects may explain why 40% of American adults reported struggling with mental health or substance abuse or why 10% of American adults considered suicide during the late-June study period .
Isolation strategies also restrict one’s access to physical activity, especially if done indoors or in groups. Mobility changes in cell phone location data highlight this effect. Per August 11, 2020, United States statistics, movement in retail and recreation (-13%), grocery and pharmacy (-3%), transit stations (-31%), and workplaces (-38%) have all decreased since January 2020 . (-13% notes a 13% decrease from January’s average.) Still, the mobility trend for parks, places like national parks, public beaches, dog parks, and public gardens, has increased by 57% nationally. But, the specific state strongly regulates this, e.g., +134% in Alaska, +543% in South Dakota, and +142% in Oregon, but -16% in Arizona, -12% in Nevada, and +20% in California .
Yet, many Americans do not have access to wide-open national parks and beaches or have had their access to these areas limited by local authorities  , which has put petty and inconsistent restraints between two citizens' ability to exercise. Physical activity restraint is particularly concerning because general physical activity is typically widely accessible and free, especially since research shows that physical activity can have robust and beneficial effects on anxiety and depression. In a 2015 paper titled "The Effects of Stress on Physical Activity and Exercise," the authors noted that physical activity is known to have robust beneficial effects on anxiety and depression, which is likely more increased when done outdoor or in groups . But, chronic stress can reduce one's readiness to engage in physical activity . Say, however, that public health experts and state officials encouraged physical activity to the same degree that they have encouraged self-isolating or wearing a mask. One could reasonably extrapolate that Sally would be a good citizen and follow recommendations to engage in physical activity, even if she participates in physical activity while social distancing.
I argue that these officials have not placed enough emphasis on physical activity during this period.
In addition to the well-researched and -established beneficial effects of regular physical exercise on all-cause mortality, especially physical activity's beneficial impact on COVID-19 risk factors for a severe COVID-19 disease outcome  and its immunological benefits  (finding that exercise promotes immunoglobin circulation and anti-inflammatory cytokines; finding that with hear daily exercise, the body undergoes cellular and biological changes that enhance immune defense activity and metabolic health), physical activity's mood-enhancing, stress-alleviating, and long-term mental health-improving effects  are highly relevant for today's social situation. Therefore, physical activity must be a crucial part of one's response to COVID-19.
This recommendation should also be more strongly encouraged by mental health practitioners to those who began to suffer from mental illness during this epidemic or those who generally suffer. Based on recent reports, the use of psychiatric medicines and antidepressants increased 34% from mid-February to mid-March, and 78% of all antidepressant and anti-insomnia prescriptions filled during the week ending March 15th were for new prescriptions  . These medications have equivocal data supporting their effects because they tend to cause more harm than they prevent, with a broad spectrum of adverse side effects such as the psychiatric prescribing cascade . However, physical activity is relatively safe and free.
Merely engaging in physical activity three to five days a week for 30 minutes can significantly improve depression or anxiety symptoms and relieve chronic stress . A great way to begin is searching for a local state or county park near your home and setting aside 30 minutes a day to go on a walk. The type of physical activity is not necessarily crucial because any physical activity is better than none. Still, research shows that cycling, jogging, and walking are more effective than household exercise when improving mental health . So, go outside, and enjoy some fresh air and sunshine. Nevertheless, I would be hard-pressed to believe that public health experts and governors do not know the benefits of physical activity on mental health, making the lack of a clear and straightforward recommendation dubious at best.
If you are interested in reading more about stress and its effects on the body, check out “Cortisol’s Effects and How to Reduce it Naturally.” And if you have questions about any products, call our office at 800.726.1834.