NuroseneNov 24

How Exercise Affects Your Immune System

It’s the dependable workhorse of your body.

A man in a jacket and beanie jogs during the morning hours while listening to music

We’ve got cold and flu season, seasonal allergies, and a long list of viruses, bacteria, and parasites knocking on our door 24/7/365, to say nothing of the ongoing pandemic.

Despite this, our immune system does a remarkable job of keeping most of us safe and healthy.

Sure, we may get the sniffles from time to time, and we might need a couple of days away from work or school to recover from a bad bout of influenza, but our immune response to foreign invaders is successful more often than not.

And we are under near-constant attack.

There’s always another virus, bacteria, fungi, or parasite — collectively known as pathogens — trying to sneak past our defenses. If they do, it can lead to disease, infection, or other harmful changes within the meticulously balanced environment that is our body.

The Immune System: A Quick Refresher

Various organs — including the brain — proteins, chemicals, and white blood cells work together to identify and eliminate foreign pathogens.

The skin acts as the first line of defense, while mucous membranes and other secretions, like tears, protect us at any opening in the skin (mouth, nose, eyes, and so on). A cut or scratch makes us vulnerable to an invading pathogen.

White blood cells called phagocytes attack any pathogen that gets inside the body. Phago comes from the Greek word for “eat or devour”, and that’s exactly what these cells attempt to do.

Next, B-cells and T-cells — two types of white blood cells called lymphocytes — go into search and destroy mode. A pathogen carries an identifying antigen on its surface, and B-cells will produce an antibody that attaches to it like a lock and key. B-cells can also “remember” certain antigens from a previous encounter (which is why you can’t get chicken pox a second time, for example).

The antibodies then send a signal to the T-cells to attack and destroy.

At first glance, you might think of the immune system as defense only, but research over the past few years is revealing it as so much more.

“The immune system is a highly evolved communication system that dynamically processes information from both its internal and external environments and then mediates its function accordingly.” — Dan Gallucci, CIO and Co-Founder of Nurosene

It is more precisely a communication system, both reactive and proactive in keeping the body healthy and operating at peak performance.

Therefore, a strong and robust immune system is obviously crucial.

Giving It a Boost

There are plenty of ways to boost or support your immune system: eating certain foods like citrus fruits, turmeric, or garlic, getting enough restorative sleep, keeping up-to-date on vaccinations, avoiding toxins like alcohol, managing the amount of chronic stress in your life, and more.

One of the simplest ways is exercise.

Exercise + Immunity

Even just a few years ago, there was a lot of disagreement within the scientific community on the impact of exercise on the immune system.

The widely accepted — though rarely tested — “open window” theory maintained that bouts of intense physical activity left us immunocompromised and vulnerable to opportunistic infection.

New studies have shown that is not true. In fact, the data reveals the opposite: regular exercise can lower the risk of infection and reduce inflammation.

But that’s not all.

Physical activity not only releases endorphins — the “feel good” chemical — but also reduces the amount of stress hormones like cortisol. It eliminates stress and elevates our mood.

Exercise is obviously a key component of a balanced lifestyle, and along with diet, the top strategy for maintaining a healthy weight.

Chronic stress and obesity negatively impact our immune system, so exercise not only boosts our immune response directly, it also reduces or eliminates two of the biggest factors working against it. Win-win-win.

Training the Troops

Most of the time, we have a limited number of white blood cells — our infantry in the war on pathogens — circulating in our bloodstream. Most of them remain in lymphoid tissues or organs like the spleen.

Exercise increases both blood and lymph flow, which increases the rate and number of white blood cells circulating around the body. Think of it as strength and cardio training for your soldiers.

The more natural killer cells and T-cells roaming the body, the faster they’re able to find and kill foreign invaders. One soldier guarding the perimeter at night is only so effective. Increase that number to 50, and little if anything is going to get through.

Studies have found that those who took a brisk 45-minute walk enjoyed these increased numbers for up to 3 hours afterwards.

Another discovered that individuals engaging in aerobic exercise for at least 5 days each week lowered the number of upper respiratory tract infections by 43% over a three month period.

More defenders. Better trained. More robust.

Everything in Moderation

Much of the research has focused on acute exercise, which is moderate to vigorous activity for up to an hour. It includes walking, jogging, spin class, or elliptical workouts.

But as we all know, it’s possible to have too much of a good thing. High intensity activities for more than an hour — those that put your body into a state of stress — can lead to lowered immune function.

So aim for the sweet spot. Experts suggest starting with a ten-minute walk a few times per day. You can gradually increase the time and pace. There is mounting evidence that people who are more active have an overall lower risk of acute and chronic illnesses.

The Conversation Pace Exercise — found in the NURO app (available for iOS and Android) — suggests a walk, jog, swim, or bike ride 3x/week. You should feel slightly winded, but still able to carry on a conversation. The sweet spot.

As always, listen to your body when engaging in physical activities. Pay attention to aches and pain.

And as a rule of thumb, remember:

An infographic of exercising in the colder months. If you have symptoms above the neck, recover. If you have symptoms below the neck, give it a try and see how you feel.

Don’t push yourself harder or faster than necessary.

Train your troops. Be balanced. Live healthy.