A little exercise goes a long way to making your immune system strong
During COVID-19 and now coming into flu season there’s been a lot of talk about ‘boosting or strengthening one’s immune system by doing…….’ Like your immune system can be that easily manipulated.
Hint, it’s not.
This gives some false hopes because of slick marketing and paid endorsements claiming otherwise.
Supplements can help your immune system but the big rocks of diet, exercise, and reduced stress work best. Let’s dive into the ins and outs of the immune system and how exercise helps strengthen your immune system.
What Is The Immune System And How Does It Work?
There is a lot of talk about the immune system but what is it?
It’s a complex network of cells, tissues, and organs and together they help the body fight infections and other diseases.
This network includes:
- Your skin, which helps prevent germs from getting into your body.
- Mucous membranes, the moist, inner linings of organs of the mouth, nose, eyelids, windpipe and lungs, stomach and intestines, and the ureters, urethra, and urinary bladder. They produce mucus and other substances which can trap and fight germs.
- White blood cells, which fight germs.
- Organs and tissues of the lymph system, which produce, store, and carry white blood cells.
When germs such as bacteria or viruses (antigens) come into your body, they attack and multiply causing an infection. Then your immune system kicks in to protect you from infection by fighting off these antigens. (1)
Plus, your immune system has a good memory even if you don’t.
After an infection, your immune system remembers the antigen and if it sees this again, it recognizes it and sends out the right antibodies, to fight it. This protection against certain diseases is called immunity.
And this is where a lot of people get confused. You cannot boost your immune system with just supplementation. You literally boost it by getting sick.
There’s More Than One Type Of Immunity
There are three different types of immunity which are:
Innate immunity is the protection you’re born with and it’s the first line of defense against antigens. This immunity includes barriers such as the skin and mucous membranes, which help keep harmful substances from entering the body.
Active immunity is developed when you’re infected with or vaccinated against a foreign substance, like the flu shot. Active immunity can be long-lasting and for many diseases, it lasts your whole life.
Passive immunity happens when you receive antibodies to a disease instead of your own immune system making them. For example, newborn babies get antibodies from their moms. This immunity gives you immediate protection but only lasts for a few weeks or months.
How Exercise Helps The Immune System
Note- For now, there are no scientifically proven direct links between lifestyle and enhanced immune function. The following are theories not fact.
Exercise increases blood circulation and has an anti-inflammatory effect on the body which can improve immunity.
Although the immune system is a complex network, people have only a few immune cells circulating around the body at any given time.
Plus, these immune cells like to ‘hang out’ in organs like the spleen, where your body can easily kill viruses, bacteria, and other microorganisms that cause infections and disease.
Because exercise increases blood and lymph flow circulation as your muscles contract and relax, this increases the circulation of immune cells, making them roam the body at a higher rate and at higher numbers.
Then exercise recruits specialized immune cells—like natural killer cells and T cells to find antigens and kill them.
While this happens straight away (while exercising), this uptick in immune cells doesn’t stick around, unless you exercise consistently (2)
So, it pays to keep active.
What Types Of Exercise Strengthen The Immune System?
Methods of exercise, ones that get the blood circulating will improve the workings of your immune system. But here I’ll concentrate on what the research says about aerobic, anaerobic and strength training.
A 2015 study by Stanford University linked 90-minute bouts of walking outdoors to decreased activity in the part of the brain that’s associated with depression. Less stress means a better functioning immune system.
In a 2019 review ‘The compelling link between physical activity and the body’s defense system’, people who took a 45-minute brisk walk experienced an increase of immune cells floating around the body for up to three hours afterwards.
The British Journal Of Sports Medicine found people who participated in aerobic exercise five or more days a week lowered the number of upper respiratory tract infections (like the common cold) over a 12-week period by more than 40%. (3)
They’re is more to cardio than burning calories and reducing stress. It prevents you from getting sick too. But you need to be consistent to fully reap the immune system benefits.
High Intensity Interval Training
Here we’re talking about sprint and other timed interval methods of cardio that have you going all out for 10-30 seconds followed by a easy rest period.
There was a suggestion HIIT workouts were damaging to the immune system because they suppressed the body’s immune response for a time after you finished.
However, Frontiers in Immunology challenged this idea of HIIT of suppressing the immune system in a 2020 paper in Exercise Immunology Reviews. They confirmed that increasing exercise intensity does not suppress immunity or increase the risk of infection. (4)
So, if you like going hard, your immune system can handle it and get stronger because of it
They found this suppression is multifactorial and it is usually weakened due to anxiety, sleep disruption, travel, nutritional deficits, and environmental extremes.
Taking your cardio outdoors may strengthen the immune system even further by engaging the body’s parasympathetic “rest and digest” system, according to 2015 research published in Frontiers in Psychology.
The parasympathetic system works against your sympathetic “fight or flight” system to reduce physiological stress levels and lower excess inflammation that can inhibit healthy immunity. (5)
Beyond looking great in the mirror and for you and your partner, strength training leads to improved coordination, better cognitive function, higher bone density, and reduced back pain. (6)
And big biceps. Don’t forget those.
Strength training and cardio increase the circulation of immune cells, making them roam the body at a higher rate and at higher numbers.
The difference is strength training can increase the number of white blood cells circulating during exercise and two hours post exercise. Further strengthening the immune system, particularly innate immunity, your first line of defense. (7)
And to ensure proper recovery after intense strength training make sure to eat carbohydrates to replace glycogen (sugar) in your muscles and get some sleep.
Because while you’re sleeping, the body produces 1-GF, a hormone that helps repair and build muscle. (8)
We associate exercise for what it does for the outside of our bodies but forget what it does for the inside. Regular exercise will ensure a better functioning immune system, one that jumps into action when necessary.
Because your immune system loves to flex too.
- What are the organs of the immune system? InformedHealth.org.
- David C Nieman,, Laurel M Wentz. The compelling link between physical activity and the body’s defense system. J Sport Health Sci. 2019 May;8(3):201-217.
- David C Nieman et al. Upper respiratory tract infection is reduced in physically fit and active adults. Br J Sports Med. 2011 Sep;45(12):987-92.
- Richard J Simpson et al. Can exercise affect immune function to increase susceptibility to infection? Exerc Immunol Rev. 2020; 26:8-22.
- Ming Kuo. How might contact with nature promote human health? Promising mechanisms and a possible central pathway. Front Psychol. 2015 Aug 25; 6:1093.
- Wayne L Westcott. Resistance training is medicine: effects of strength training on health. Curr Sports Med Rep. Jul-Aug 2012;11(4):209-16.
- Ayla Karine Fortunato et al. Strength Training Session Induces Important Changes on Physiological, Immunological, and Inflammatory Biomarkers. J Immunol Res. 2018; 2018: 9675216.
- Jonathan M Peak et al Recovery of the immune system after exercise. J Appl Physiol (1985) 2017 May 1;122(5):1077-1087.