Exercise May Be 'The Most Important Medicine' for COVID-19: Study

New evidence suggests that exercise should be a first-line strategy in the prevention and treatment of COVID-19 and long COVID.
Exercise May Be 'The Most Important Medicine' for COVID-19: Study
Allison DeMajistre

"Exercise is the most important medicine for COVID-19," according to a recent review published in Current Sports Medicine Reports.

More than 6.4 million deaths globally have been attributed to COVID-19 as of September 2022. Vaccinations, boosters, handwashing, social distancing, and masking have proven ineffective for many, with fully vaccinated individuals becoming infected and experiencing anywhere from mild symptoms to adverse outcomes, including extended hospital stays and even death.
As new mutations continue to arrive, some researchers believe that it's time to focus on using exercise as a first-line strategy in preventing and treating COVID-19 and long COVID. According to a recent American Journal of Preventative Medicine study, "public health leaders should add physical activity to pandemic control strategies."

Clinical Evidence

According to the review in Current Sports Medicine Reports, by consistently meeting exercise guidelines, people can reduce hospitalization for COVID-19 by up to 42 percent, ICU admission by up to 38 percent, and death by up to 83 percent across major demographic subgroups and those with and without chronic conditions.
There are now more than 25 studies and a meta-analysis reporting that those who were consistently inactive had more detrimental effects from COVID-19 than those who were regularly physically active.
A 2022 review published in the Journal of Sport and Health Science found that severe COVID-19 risk reduction in physically active groups can be attributed to exercise-induced immunoprotective effects, including reduced chronic inflammation. Researchers wrote, “Scientific consensus groups, including those who submitted the Physical Activity Guidelines for Americans, have not yet given this area of research the respect that is due.”

The Current Sports Medicine Reports study found that regular physical activity with at least 150 minutes of moderate-intensity weekly exercise, or 75 minutes of high-intensity weekly exercise, gained the most significant benefit, with an 11 to 22 percent lower risk of contracting the infection.

Stuart Hoover, a naturopathic practitioner, told The Epoch Times, “Most of our population is inactive and obese, and in that situation, the body’s immune system is not up to par.”

Effect of Exercise on Organ Systems

It’s important first to understand the effect of exercise at the cellular level, starting with exerkines and their effect on all body systems. Exerkines are signaling molecules released from skeletal muscle, brown adipose tissue, white adipose tissue, neurons, the heart, and the liver in response to exercise. They come in many forms, such as hormones, proteins, metabolites, and nucleic acids. These exerkines play a potential role in improving cardiovascular, metabolic, immune, and neurological health.
Even in the absence of COVID-19, exerkines have the potential to treat cardiovascular disease, Type 2 diabetes, and obesity. However, through molecular signals and pathways, exercise releases exerkines that can lessen the effects of COVID-19 and long COVID on organ systems.

Cardiovascular System

COVID-19 causes several paths of dysfunction in the cardiovascular system, including increased incidence of blood clots and high blood pressure. Additionally, COVID-19 causes inflammation in coronary arteries, which can speed up plaque formation and cause blockages in the heart. In long COVID, inflammation leads to increased problems with blood vessels that result in deep vein thrombosis, pulmonary embolism, and bleeding events.

Exercise has an anti-inflammatory effect, which may help alleviate systemic heart tissue inflammation from COVID-19.

“We know that COVID is a disease that affects the circulatory system, and people who exercise have healthier circulatory systems, so they are better prepared to weather a COVID storm,” Andrew Noymer, an epidemiologist and associate professor of population health and disease prevention at the University of California–Irvine, told The Epoch Times.

Multiple exerkines are released during exercise, promoting blood vessel growth, production, and function while repairing cardiac tissue, improving blood pressure, and preventing chronic diseases such as diabetes and cardiovascular disease.

Respiratory System

The virus that causes COVID-19 enters the body through the respiratory tract. Once infected, the virus replicates and spreads throughout the upper and lower respiratory tract.
Defending against COVID-19 requires healthy immune and respiratory systems. Increasing aerobic capacity can immediately affect the immune system through three mechanisms:
  • It increases the amount and function of immune cells, including T lymphocytes, neutrophils, macrophages, and monocytes.
  • It increases immunoglobulin IgA, which, alongside immune cells, can fight lung infections.
  • It regulates inflammatory proteins with a short-term increase to fight lung infections and a long-term decrease to inhibit a reduction in lung function.
“The more we can move blood, the more we circulate robust immune cells. They’re hitting more areas of the body and finding more bacteria and viruses to attack,” Mr. Hoover said.
Exercise can even produce antioxidative effects by releasing myokines, proteins that can protect against oxidative stress-related disease and benefit the respiratory system when battling COVID-19.

Neuroendocrine and Nervous System

Neurological consequences of COVID-19 can be mild to severe, ranging from headaches and loss of smell to hemorrhagic stroke and Guillain-Barré syndrome. There have also been autopsy reports showing widespread brain lesions in the COVID-19 deceased.

Long COVID can cause devastating neurological symptoms in the brain, including tinnitus, hearing loss, vertigo, brain inflammation, chronic fatigue syndrome, and anxiety and depression. Neurological symptoms can result from either the neuropathic effect of the virus or an indirect effect of neuroinflammation.

Specific exerkines released during exercise can enhance the growth and development of brain tissue and improve mood and cognition, making them a helpful medicine in negating the detrimental effects of COVID-19 and long COVID.

Additionally, some of the neuro-specific exerkines that are released with exercise also affect the neuroendocrine system by increasing insulin uptake and mitigating the adverse effects of COVID-19 on glucose control, further evidence that exercise is a necessary medical intervention to alleviate the effect that COVID-19 has on the neuroendocrine system.

Immune System

A robust immune defense is essential in fighting the COVID-19 virus. Many people with a delayed immune response can experience both pronounced COVID-19 symptoms and long COVID.

The T cell-mediated adaptive immune response is a major determinant of the clinical outcome of SARS-CoV-2 infection.

The thymus gland produces T cells; however, the highest T-cell production happens in childhood, and eventually, the gland is almost entirely replaced with fat tissue. T cells go on to survive, stored in the lymph nodes, and become active when an antigen is introduced into the body, like a virus.

Older people often have ineffective and nonfunctional T cells, making them more at risk of severe infection. “The most severe outcomes of COVID are associated with age, so we’re seeing most mortality in older people, and at any age, people who exercise may fare better,” Mr. Noymer told The Epoch Times.

People with exhausted T cells experience a delayed protective immune response during the initial infection, which causes an increase in viral load. As the virus load gets higher, T cells compensate by sending out cytokines that signal other immune cells to assist in fighting the virus. Unfortunately, this can result in a cytokine storm, an intense inflammatory response that can lead to immune cells attacking healthy areas of the body.
Exercise increases and mobilizes immune cells into the bloodstream and may directly stimulate the immune system. Exercise also releases different myokines that specifically target the thymus gland to increase T-cell output, ultimately protecting T cells from the effects of COVID-19.

Mechanisms for Repair of COVID-19 Organ Damage

A hallmark of debilitating and deadly cases of COVID-19 has been multi-organ damage, including of the heart, lungs, liver, kidneys, pancreas, and spleen. Exercise releases stem cells to repair damaged heart and skeletal muscle tissue. Exercise also stimulates bone marrow to generate immune cells and release cells that help grow and heal blood vessels.
Another vital mechanism to heal damaged organs is autophagy, the cellular recycling process. COVID-19 infection damages mitochondria, a cell's powerhouse and the body’s primary source of energy production. With every exercise session, the damaged cells of all body systems go through autophagy, cleaning up nonfunctioning, damaged mitochondria and other cells to optimize energy production and maintain skeletal muscle health.

Additional Recommendations

“I don’t know any doctor who would say exercise will hurt you,” Mr. Hoover said. “People with adrenal issues or prone to cardiovascular events need to approach exercise more slowly, but we all have to start somewhere.”

He suggests increasing intensity as the body adjusts.

Research continues to show the cellular and molecular pathways and mechanisms that exercise affects and the effects of exerkines on all body systems. Such findings reinforce the assertion that physical activity can help mitigate COVID-19 infection and address currently “untreatable” symptoms of long COVID.

Mr. Noymer cautions: “It’s important for your readers to keep in mind that exercise will not prevent COVID infection entirely. Age is the most significant factor in severe COVID, and Father Time comes for us all, regardless of how much we exercise.”

Allison DeMajistre, BSN, RN, CCRN is a freelance medical writer for The Epoch Times. She is a registered nurse who previously worked in critical care. She specializes in cardiology-related topics.