Does exercise boost the immune system?

In short, yes. Exercise benefits your body in many ways, and boosting your immunity is just one of them. But there is an important caveat: the frequency, duration and intensity of your workouts do matter.

Research shows that when it comes to boosting your immunity, moderate-intensity exercise is best (1).

In general, exercise at a moderate to vigorous intensity for 60 minutes or less is optimal for the benefits of exercise on the immune system. If you do this daily or almost daily, your immune and metabolic systems continue to strengthen, building on earlier gains (2).

On the other hand, prolonged high-intensity training — especially without proper rest between sessions — can weaken your immune system (2).

This is an important consideration if you are a competitive athlete or training for an endurance event like a marathon. In these cases, take extra precautions to give your body enough recovery time.

Before discussing how physical activity can help your immune system, it’s important to discuss how much exercise you likely need for your overall health.

According to the US Department of Health and Human Services (HHS), most adults should get at least 150 to 300 minutes of moderate-intensity aerobic activity or 75 minutes of vigorous physical activity each week (3).

The HHS also recommends doing at least 2 days a week of muscle-strengthening activities involving all major muscle groups in the legs, hips, back, abdomen, chest, shoulders, and arms.

Being active most days of the week is a great goal for improving your overall health and well-being. It’s also a great place to start if you want to boost your immune system.

A healthy immune system protects your body from bacteria, viruses and other pathogens that you encounter on a daily basis.

Here are 6 ways exercise can help your immune system.

1. Exercise Boosts Cellular Immunity

According to a 2019 research review, moderate-intensity exercise can boost cellular immunity by increasing circulation of immune cells in your body. This helps your body better prepare for a future infection by detecting it earlier (2).

Researchers have found that performing aerobic exercise at moderate to vigorous intensity for less than 60 minutes (an average of 30 to 45 minutes) increases the recruitment and circulation of the immune system’s best defensive cells (2).

These results indicate that regular exercise can boost immune defense activity, making you more resistant to infections and better equipped to deal with infectious agents that have already gained ground in your body (4).

2. Exercise raises body temperature

Unless you’re moving at a snail’s pace, your body temperature will rise during most forms of exercise and stay elevated for a short time after a workout ends (5).

Why is this important? It is commonly believed that this brief increase in body temperature during and after exercise can prevent bacteria from growing and help your body better fight off an infection, similar to a fever.

Yet, it is important to note that this claim lacks factual evidence.

Although this temporary increase in temperature is not as significant as the increase you experience with a fever, it can still benefit your immune system.

3. Exercise helps you sleep better

Regular physical activity can help improve the overall quantity and quality of sleep (6).

This is great news because sleep loss can negatively affect parts of the immune system (7).

Some research indicates a higher risk of infection and development of cardiovascular and metabolic disorders due to reduced antibody and inflammatory cytokine production in people with modest sleep loss (8).

4. Exercise reduces the risk of heart disease, diabetes and other diseases

Exercise can reduce cardiovascular risk factors, prevent or delay the development of type 2 diabetes, raise HDL (good) cholesterol, and lower resting heart rate (9, ten, 11, 12).

Having one or more of these conditions can make it harder for your immune system to ward off infections and viral illnesses such as COVID-19 (13).

5. Exercise decreases stress and other conditions such as depression

There’s a reason people love working out after a long day at work: it helps reduce stress.

Specifically, moderate-intensity exercise may slow the release of stress hormones while positively influencing neurotransmitters in the brain that affect mood and behavior (14, 15, 16).

Additionally, regular exercise may provide a protective benefit against stress — meaning that exercise helps you proactively manage stressors with more resilience and improved mood (17, 18).

According to some research, stress and depression can have a dramatic impact on the regular functioning of the immune system, resulting in a state of chronic low inflammation that promotes infection, disease, and other illnesses (19).

6. Exercise reduces inflammation

Inflammation is a normal immune system response that your body uses to fight off pathogens or toxins.

Acute inflammation isn’t necessarily a problem, but when this acute response goes unchecked, it can become chronic and potentially lead to a host of inflammatory diseases (20).

Research has shown that exercise can reduce inflammation and keep this immune response in check — but exercise intensity matters (21).

Studies suggest that moderate-intensity exercise reduces inflammation, while prolonged periods of high-intensity exercise may actually increase inflammation (22).

Take-out? Moderate exercise with appropriate rest periods can maximize the effectiveness of your body’s inflammatory immune response, reducing your risk of chronic inflammation.

Summary

Regular exercise can improve sleep, improve mood, reduce stress levels and increase circulation of immune cells in your body – all factors that contribute to a healthy immune system.

We constantly hear about the importance of a strong immune system, especially when it comes to preventing viruses, infections, and other illnesses.

But what exactly is the immune system and how essential is it to your overall health?

For starters, your immune system is made up of cells, organs, tissues, and even reflexes such as your cough reflex. Its main job is to repel or limit infections and other diseases.

When your body detects an antigen — something harmful or foreign, like a virus, toxin, or bacteria — your immune system kicks in to protect you by attacking it. This is called an immune response (23).

During this response, your body makes antibodies, which can help you defend against this antigen in the future. This protection your body builds is called immunity.

The immune system has two parts: the innate immune system and the acquired, or adaptive, immune system. You are born with the innate immune system, and it is active right after birth.

The innate system consists of protection offered by the mucous membranes and your skin and protection offered by the cells and proteins of the immune system. It reacts the same way to all germs (24).

As you grow, your body learns things and develops acquired immunity, which either comes from a vaccine, exposure to a virus or disease, or antibodies from another person. Acquired immunity can take over if the innate system does not destroy germs.

The acquired immune system can remember germs, so it can specifically target the type of germ causing an infection and hopefully prevent you from getting sick.

Summary

The immune system is made up of cells, tissues, and organs that fend off or limit infections and other illnesses.

You might want to think twice about going out for a run or to a crowded gym if you’re not feeling well.

Exercising while sick can make your condition worse or delay your recovery, especially if you have a fever or have severe symptoms (2).

It also puts others at risk of getting sick if your disease is contagious.

To decide how to proceed, you will need to take stock of your symptoms.

If you experience symptoms above the neck like stuffiness, sneezing, sore throat, and runny nose, you may have a cold and are okay with light to moderate exercise (25, 26).

But if you have a fever or chills, body aches, cough, or nausea, you could be dealing with a more serious illness, such as the flu or COVID-19 (25, 26, 27).

If so, skipping your workout is probably in your best interest.

Summary

You should listen to your body and take note of your symptoms before exercising when you are sick. If your symptoms are above the neck, you may be able to train. But if you have more severe symptoms like fever, rest is the best option.

Making moderate exercise a regular part of your routine contributes to your overall health and helps support your immune system.

If you’re new to exercise or have questions about how physical activity fits into your life, be sure to talk to a healthcare professional. They can help you determine the best type of exercise for you.