In the current climate, with ways to fight coronavirus in mind, many people are wondering can exercise improve your immune system? There has been an unprecedented surge in people trying to identify what can weaken the immune system along with how to naturally “boost” the immune system. So, is it possible, and if so, what is the best exercise for the immune system?
With many sports facilities and gyms closed down, people may be wondering how to avoid the Covid 19 virus, and consequently avoid exercising altogether. But could that be one of the things that weakens your immune system response? Of course, to every coin, there are two sides, so it would be remiss not to discuss does exercising lower your immune system. Finally, are all those articles about how to naturally boost your immune system misleading or can you really boost your immune system? Let’s see what the evidence-based facts have to say!
Is boosting your immune system a myth?
In short, the simple answer is yes! The term ‘boost’ is somewhat misleading and the concept of being able to boost your immune system is unfortunately elusive so far! The primary reason being that the immune system is an intricate delicate system, with emphasis on the word ‘system’ – it’s not just one single entity, it’s a compilation of multifaceted components, which all work interdependently to safeguard your body from harm. However, there are ways to support the immune system, all of which can be accomplished by one simple act: a healthy lifestyle! In this article, the focus will be on if exercising helps immune system functionality.
Does exercise strengthen your immune system?
Adopting a healthy lifestyle is paramount to maintaining overall health and to get a healthy immune system. One of the pillars to a healthy lifestyle is regular moderate exercise. Fortunately, there are early studies which indicate that people who exercise recreationally were likely to develop fewer colds once they began running routinely.
A study examined people who exercised 5 times a week for 30-40 minutes at moderate levels of exertion and achieved 70-75% of their VO2 max. It found that these people experienced 50% less sick days due to sore throats and colds when compared with sedentary people who didn’t exercise.
Moderate levels of exercise is linked to increased macrophage production which are responsible for fighting bacteria. Other studies have shown that moderate exercise leads to temporary physiological changes in the body; immune cells are thought to move more rapidly throughout the body during exercise, making them more capable of eliciting an attack on bacteria. These immune cells then return to normal over a few hours once exercise ceases.
In addition, transient bouts of exercise have been shown to promote anti-inflammatory and anti-oxidant responses, which can contribute to enhanced immunosurveillance (process whereby immune system cells seek and recognise foreign pathogens). Evidence points to reduced anti-inflammatory biomarkers present in individuals who exercise moderate pace and regularly. This could be particularly advantageous for people with high levels of physical activity and fitness who are suffering from acute and chronic inflammatory diseases, such as arthritis, obesity, cardiovascular disease and even cancer.
You may be wondering does stress weaken your immune system? The short answer is yes. Fortunately, research points towards the positive effects of exercise on stress reduction as an indirect aid to strengthening the immune system naturally. Additionally, stress hormones released by the body during short, moderate bouts of physical exertion do not reach elevated levels sufficient to suppress immune cells. Over time, immunosurveillance is enhanced by transient periods of exercise-induced increases in lymphocyte subsets. Ultimately, it is widely accepted that the long-term effects of regular moderate exercise on immune system effectiveness can be significantly positive.
Are you wasting money on expensive supplements or curious about their effectiveness? Then check out the best supplements to fight coronavirus – do they even exist?
Does exercise weaken your immune system?
We’re all familiar with the saying, ‘everything in moderation’, and the same principle applies to exercise. When researching to determine if exercise lowers immune system responses, a particular study succinctly answered the question. The study involved 32 elite athletes, 31 recreationally competitive cyclists and triathletes and 20 sedentary people (control group) who were surveyed over a 5-month training and competition period. Subjects who presented with 2 or more upper respiratory symptoms were swabbed to determine the type of illness. This limited study observed the following rates of upper respiratory illness amongst the 3 categories of participants:
- Elite athletes: 66% developed upper respiratory illness
- Recreational athletes: 22% developed upper respiratory illness
- Sedentary people: 45% developed upper respiratory illness
The study concluded that immune suppression was highest in elite athletes, while sedentary people who performed little to no exercise were the next most susceptible cohort for developing upper respiratory symptoms. As such, moderate exercise strengthens immune system response. To put this into context, the exercise that lowers immune system response can include but are not limited to:
- Lengthy workouts extending 1.5 hours or more where there is no refuelling throughout the workout
- Exercises with inadequate recovery periods
- Workouts of relatively high intensity performed over a moderate duration of time
In fact, research has shown that 90 minutes of intense exercise can make athletes susceptible to developing illnesses for up to 3 day later.
So how does exercise weaken the immune system? Many theories pertain to the possible reasons why exercise could alter immune responses. Exercising releases elevated levels of the hormones, norepinephrine and cortisol, which are both hormones with response mechanisms towards stress. These hormone releases are associated with reduced immune cell availability. Some of the potential factors which could be attributed to increased susceptibility for upper respiratory infections include:
- Athletes having an increased exposure to the outdoors during exercise where airborne pathogens persist
- Physical stressors associated with running (breathing harder) which can cause the airways to dry out
- Inadequate nutrition and refuelling during periods of excess exercise – foods strengthen immune system response
- The psychological impact of exercise on the body can lead to brain fatigue and feelings of susceptibility towards illness
All that being said, while the theories seem rational, limited conclusive evidence exists to date which substantiates that exercise lowers immune system response.
What is the best exercise for the immune system?
There is a general consensus that advocates moderate exercise on immune system response for optimal performance. An article posted in the International Journal of Physical Education, Sports and Health endorses aerobic exercise for the immune system to function at peak levels. Examples of exercises recommended include:
The article elaborated further to specify that optimal aerobic exercise would consist of 30-40 minutes of moderate exercise 5 times a week, for instance – a brisk walk where the output ranges between 70-75% of your VO2 max. Of course, care needs to be taken when a person is sick, tired or fatigued; the best way to gauge this is by listening to your body. Overexerting yourself could be doing more damage than good!
- Exercise is one of the essential pillars to a healthy body and immune system
- The best exercise for the immune system is moderate aerobic exercise
- Exercising moderately 5 times a week for 30-40 minutes can strengthen the immune system naturally
- Elite athletes followed by sedentary people are more susceptible to illness than recreational athletes
- Exercise can also reduce stress which indirectly can adversely affect the immune system
- Don’t forget to adequate fuel your body with protein, fat and carbohydrates
I’d love to hear you feedback and experiences in the comments section below. Have you found that exercise strengthens your immune system and that you’re less sick or do you still think exercise lowers immune system response? Do you take any supplements or foods that help boost your immune system (or so we are led to believe)?
Harvard Health., 2020. How To Boost Your Immune System – Harvard Health. [online] Harvard Health. Available at:
Nieman, D. and Wentz, L., 2019. The compelling link between physical activity and the body’s defense system. Journal of Sport and Health Science, 8(3), pp.201-217.
Paleo Leap | Paleo diet Recipes & Tips. 2020. How Much Exercise Is Too Much? Ask Your Immune System | Paleo Leap. [online] Available at:
Quinn, E., 2019. Intense Exercise May Actually Make You Sick. [online] Verywell Fit. Available at:
Spence, L., Brown, W., Pyne, D., Nissen, M., Sloots, T., McCormack, J., Locke, A. and Fricker, P., 2007. Incidence, Etiology, and Symptomatology of Upper Respiratory Illness in Elite Athletes. Medicine & Science in Sports & Exercise, 39(4), pp.577-586.
Sreenath S. Exercise and immune system. International Journal of Physical Education, Sports and Health. 2017; 4(1): 200-202.