After dealing with COVID-19 for over 18 months, folks are asking more questions about the impact that exercise has on your immune system.  We know that reports show, those with reduced immune systems are more susceptible to the virus and damage to the body if you get COVID.  

Multiple studies in humans and animals have demonstrated the profound impact that exercise can have on the immune system. There is a general consensus that regular bouts of short-lasting (i.e. up to 45 minutes) moderate-intensity exercise is beneficial for host immune defense, particularly in older adults and people with chronic diseases.

As well, numerous epidemiological studies have examined the effects of exercise on individuals with illness who are either moderately active or sedentary. These studies consistently show people who are active or physically fit get, significantly fewer upper respiratory tract infections (URTI) per year than less active people.

How does exercise boost the immune system?

The human immune system is a well-coordinated network of cells that recognize and destroy viruses, bacteria, and fungi. A healthy immune system requires the teamwork of two layers of immune protection: the innate immune system and the acquired (adaptive) immune system.  The innate immune system is what you are born with, and exercise stimulates it.  The adaptive immune system is what your body creates to fight off disease and what you build when you get the vaccine.

We have learned that each session of moderate aerobic exercise instantaneously mobilizes millions of immune cells. The mobilized cells first enter the blood circulation from the spleen and the bone marrow before traveling into the lungs and other organs. These cells, mobilized by exercise, are primed and ready for a fight as they patrol between circulation and tissues.

Depending on the exercise intensity and duration, the number of circulating immune cells can increase by 50% to 400%.  The most abundant type of white blood cells called neutrophils, protect us from infection and are the first cells to arrive to fight bacteria in the body.  Macrophages are types of white blood cells that engulf and digest anything that doesn’t have proteins specific to healthy body cells.  These cells make up the largest percentage of that increase. Regular moderate exercise is key to improving the immune system’s response to pathogens and reducing the risk of infection long-term.

Many health benefits can be achieved with many types of aerobic activity (e.g. walking, jogging, cycling, swimming, sports play, and Jazzercise/aerobic dance). Research shows that 20–40 minutes of moderate-intensity exercise per day is adequate to provide a positive boost to the immune system. We have all made adjustments to our life dealing with COVID and you’ll be healthier if you figure out how to add exercise back into your lifestyle. 

Those concerned with in-person activities can try exercise programs online.  Lutz Jazzercise continues to offer 45 classes in person or on Zoom in the privacy of your home.