In the age of coronavirus, education is our best chance at keeping our communities healthy and safe. We understand hand hygiene, social distancing and proper mask use. We know that exercise has countless benefits: It improves cardiovascular health, reduces depression, relieves symptoms of anxiety and aids in weight management.
However, different types and durations of exercise may actually do more harm than good to the immune system. In the world we currently know, optimizing health and immunity has become a priority.
When we consider the impact on the immune system, not all exercise is created equal. For cardiovascular health, American Heart Association (AHA) recommends that adults engage in 150 minutes of moderate activity or 75 minutes of vigorous activity per week. For children over 6 years old, 60 minutes of physical activity per day is recommended. It is recommended that adults do muscle-strengthening exercises twice a week and children over 6 years old do it three times a week.
Still, it’s known that too much exercise may actually turn a strong immune system into one that’s more susceptible to infection.
But why are some elite athletes more susceptible to infection than the average athlete? It all comes down to the body’s response to physical activity.
How the body responds to exercise
Antibodies (also called immunoglobulins) and white blood cells (WBCs) form an important part of the body’s defenses. They protect the body from foreign invaders such as bacteria and viruses. With mild to moderate physical activity, the immune system’s circulating white blood cells (especially neutrophils and lymphocytes) are increased, as are immunoglobulins. After prolonged periods of heavy, high-intensity exercise, immunoglobulins and white blood cells actually decrease. There may also be an increase in certain hormones, such as epinephrine and cortisol, which suppress the immune system through different pathways. This may explain why studies have observed increased rates of upper respiratory tract infections (URIs) in elite athletes in the days to weeks following a surge in exercise. This is particularly true for endurance athletes who average more than 90 minutes of vigorous physical activity per day.
In sports medicine, we have adopted a concept we affectionately call the “neck check,” which is applied to any athlete who is sick before being allowed to participate in a practice or game.To summarize this principle, any athlete with symptoms above the neck (usually stuffy nose, earache, sore throat) possible Still allowed to participate in exercise. Meanwhile, those who experience symptoms from the neck down — systemic symptoms such as fever, body aches, diarrhea and vomiting — are often banned from activity until symptoms resolve.
Why stop someone from exercising?
What prevents people who fail the “neck check” from engaging in physical activity is the fear of spreading disease. Certain infectious agents may also cause poor oxygenation of tissues, subsequent dehydration, and physiological damage to organs.
People who exercise while suffering from systemic illness also often begin exercising without proper hydration. Fever depletes the body’s fluid reserves more quickly, predisposing a person to complications from dehydration. The effects may be more severe in people who not only have a fever but also gastrointestinal problems such as diarrhea and vomiting. This may lead to faster dehydration.
Lack of oxygen to muscles can lead to poor performance and cell breakdown.Certain infectious agents have been shown to predispose individuals to heart disease, e.g. pericarditis or dilated cardiomyopathy (DCM), in addition to causing inflammation of other organs such as the liver and spleen.
How to exercise safely
Precautions to take when exercising include:
- keep a safe distance
- Maintain adequate hand and surface hygiene
- Note the “Neck Examination” Guidelines
- Breathe through your nose, not through your mouth. This gives the body more of its natural defenses to filter potential pathogens from the air.
Most importantly – keep moving to fuel those good, protective, immunity-boosting cells!
