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How to Strengthen Your Immune System? Just Exercise for 20 Minutes A Day, Science Says

Kaisa Kapanen
How to Strengthen Your Immune System? Just Exercise for 20 Minutes A Day, Science Says

There’s no question at all that exercise is good for us. A regular exercise regimen improves our cardiovascular health, lowers our blood pressure, and controls our weight. When it comes to specifics, however, we seem to think that more is better; as in, the more intense the workout, the better it is for our health.

Well, it turns out that quite the opposite is actually true! If you’re looking for info on how to strengthen immune system health, you’ll be happy to know that there’s plenty of scientific evidence that proves we just need 20 minutes of exercise a day to do exactly that.

This is good news, since integrating a complex exercise schedule into your life can feel like a workout in itself. In the past, the common belief was you needed a minimum of 3 to 5 times a week of rigorous gym sessions to even reap any benefits from exercise. Luckily, we now know better.

What happens to your immune system when you exercise?

The main benefits of exercise are clear, but what are the deeper scientific processes that go on in the body during and after exercise?

Per Harvard Medical School, exercise jumpstarts your blood circulation, allowing both the cells and substances of your immune system to move through the body more freely. This increases your immune cells' ability to perform their duties optimally.

The tricky part, however, is that these immune cells retreat to the tissue approximately three hours after the exercise. This behavior is why it’s vital to have regular, daily practice, rather than bursts of intense exercise sessions every now and then. 

Another great benefit of regular exercise is that it regulates local and systemic inflammation, which is what happens when the body tries to heal itself after an injury, or after foreign objects like viruses or bacteria, have entered the body. Inflammation is a normal reaction and is not dangerous in itself.

Chronic inflammation, on the other hand, happens when your body is constantly fighting off potentially harmful objects entering the body. This constant cellular turmoil can lead to other, more serious conditions, such as celiac disease, diabetes, and obesity.

How does 20 minutes of exercise strengthen your immune system?

So how did we arrive at this magic number of 20 minutes a day to strengthen the immune system?

Researchers at the University of California San Diego School of Medicine discovered that a 20-minute exercise session can give an anti-inflammatory boost for your body.  According to the study, within these 20 minutes, the immune system is stimulated to produce an anti-inflammatory cellular response.

In the study, 47 participants walked on a treadmill at an intensity level adjusted to their fitness level. Blood samples were collected before and after the exercise, and this is what the results showed: exercise doesn’t have to be intensive, or sustained for longer than 20 minutes, to produce anti-inflammatory effects in the body.

Let’s face it—HIIT-level, give-all-you-can exercise, doesn’t always feel so inviting. So the fact that 20 minutes of exercise, at a difficulty level of 55-75% of your maximum capacity, is enough to produce these yummy health benefits is beyond fantastic.

Is there such a thing as too much exercise?

It appears that yes, there IS such a thing! Exercise and immunity follow what physiologists call a “J curve.” In this model, moderate activity is the most beneficial, while both sedentariness and excessive exercising can have the opposite effect. In fact, exercising too much appears to be even more damaging than being sedentary. 

A study published in “Brain, Behaviour and Immunity” tested this with mice. In this experiment, the group most at risk for the flu were the mice that did strenuous exercise for a longer period of time. Best prepared against the virus were the mice that did moderate exercise.

This is because prolonged workouts (anything longer than 1.5 to 2 hours) suppress the body’s immune response temporarily until after the exercise is completed. The longer and the more intense you work out, the longer your immune system is down.

Because the body interprets strenuous exercise as stress, it raises your cortisol levels, thereby suppressing your immune system. Naturally, this will only make you more prone to viruses and infections. 

Tips to Boost Your Immune System

Knowing this, should we never try to run marathons or test our limits in exercise? Not exactly, but it’s a good reminder that for strengthening the immune system, less is sometimes more.

The key to a superior immune system? Make sure to tune into your body and to adopt healthy habits that will help you hit your daily goals. 

Walk that extra block with your dog and ride your bike to town instead of driving your car. Mow the lawn, eat high-nutrient foods, get enough sleep, and of course, enjoy your daily dose of yoga! Your body (and mind) will thank you.

Kaisa Kapanen
Sensitive introvert entrepreneur, writer, scubadiver, wellness enthusiast and Yin yoga lover (+teacher).