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When Is It Okay to Be Exercising While Sick?

Reading Time: 5 minutes


Date: 2022-10-06

Fitness trainers sometimes get sick. So do clients. The question is: when is it okay to push through the sore throat, runny nose, or other cold symptoms and still get in your exercise? Alternatively, when is it better to skip the workout and rest instead

We’ll address both of these questions so you know when it is and is not okay to exercise while sick. But first, let’s go over how exercise, in general, impacts the immune system.

Exercise and the Immune System

The National Library of Medicine shares that exercise boosts immune function (1). The theories behind how it does this vary. It is thought that physical activity may:

  • flush bacteria from the respiratory system, reducing one’s risk of coming down with a common cold or flu symptoms

  • prevent bacteria from growing, mainly due to body temperature rising both during and after exercise

  • cause antibodies and white blood cells to circulate through the body more rapidly, enabling them to identify and respond to an illness faster

  • slow the release of stress hormones, thereby helping to prevent illness

Research has found that exercise even helps protect against specific types of illness. For instance, one trial found that exercise helps prevent acute respiratory infection (2). This refers to a respiratory illness lasting 15 days or less. Symptoms of respiratory infection include cough, nasal congestion, and sore throat. If the symptoms are in the head, this is a sign of an upper respiratory infection. If they are in the chest, this signals a lower respiratory infection.

Another study looked at the effect of exercise on the common cold (3). It noted that working out three or more days per week was connected with a 26% lower chance of having a cold. This protective effect was more prevalent in non-smokers than in smokers.

The Centers for Disease Control and Prevention (CDC) adds that physical activity can even help prevent chronic illness (4). It offers protection against physical conditions such as type 2 diabetes, cancer, and heart disease. It also helps protect against mental health issues like anxiety, depression, and dementia.

While all of this is great, what happens if, despite your best efforts, you get sick anyway? Should you exercise when you don’t feel well or not?

When Exercising While Sick May Be Okay 

One of the best ways to help decide whether it’s okay to exercise if you’re not feeling up to par is to consider your symptoms. If your symptoms are above the neck, it is generally okay to work out. This includes having a runny or stuffy nose, sore throat, sneezing, and head congestion.

If you do decide to work out, take precautions to not spread your germs to others. When you’re done with a piece of equipment, wipe it down. You may even wear a mask to avoid sending your germs into the air.

When Rest Is Better Than a Workout

If your symptoms are below the neck, it is better to skip your workout and rest instead. This includes experiencing body aches, chest congestion, a cough, shallow breathing, vomiting, diarrhea, or an elevated body temperature. 

During your time at rest, the Mayo Clinic suggests staying hydrated (5). Take naps and hit your bed early. If you have chest congestion, drinking hot tea or some type of warm broth can help. Over-the-counter medicines may help ease coughs or the discomfort of muscle aches.

Risks of Exercising with an Illness

Some exercisers struggle with the idea of taking a day or two off from exercise—even if they have an illness or infection. If an athlete has an upcoming game, for instance, they may want to push through. People who are super intent on hitting their fitness goals might be tempted to do the same.

However, exercising when you are ill does come with some risks. If you have a fever, for instance, you run the risk of dehydration. It may even increase your injury risk. And if you have a cough, your ability to breathe is compromised. This can make it harder to take in the oxygen you need for proper cardio and muscle function.

If you have a fever, the CDC recommends staying home until it is gone (6). A fever is defined as a body temperature of 100 degrees Fahrenheit or higher (37.8 degrees Celsius). You want to be fever free for 24 hours before going out in public, let alone to the gym again.

Severe symptoms should prompt an appointment with your healthcare provider. If the illness may be due to infection, this definitely needs medical attention. For example, a productive cough could be a sign of infection. This is a cough that produces phlegm or sputum.

Related Articles: Common Communicable Diseases – How to Stay Healthy at the Gym

Workout Intensity Guidelines During Sickness

If your symptoms are above the neck and you decide to work out, the key is to not push too hard. Aim for light to moderate exercise versus doing vigorous exercise. Good physical activities when you are sick include walking, yoga, swimming, and biking. Stay away from more intense exercise, such as high-intensity interval training (HIIT) and CrossFit. 

If your symptoms are below the neck, until you feel better, you want to avoid any type of intense workout. No heavy lifting and no high intensity cardio. Also, take a break from endurance training and team sports. Once your symptoms start to lift, work back into exercise slowly. Start with light exercise and only increase the intensity when you feel up to it. 

If You’re a Fitness Trainer Who Doesn’t Feel Well

As a fitness trainer, an inability to work can hurt you financially. Not to mention, your clients rely on you. Taking this responsibility seriously can make it hard to cancel their training session even if you don’t feel well.

Yet, the same general exercise guidelines apply to you. If you have a runny nose or sore throat, holding the session may be okay. Out of respect, you want to check with your client first. Ask if they are okay working out with you if you have a mild cold. If they are, take the steps necessary to keep them from getting sick. You might want to wear a mask, for example, and keep your distance. (You may even want to take these steps to protect yourself during flu season.)

If your symptoms are below the neck, it’s best to call the session off. Explain to your client that you don’t want to make them ill. This shows them that, despite the value of regular exercise, giving your body what it needs when it’s sick is even more important. 

Exercising with a Chronic Illness

In some cases, a person’s immune system just wasn’t strong enough to fight off the latest flu or cold. Other times, illness appears in the form of chronic disease.

If you or your client has a chronic illness—such as cancer, fibromyalgia, or arthritis—not feeling well can be fairly common. Sometimes these feelings are caused by the illness itself. Other times, a specific treatment can cause general feelings of being unwell, such as when engaged in chemotherapy to treat cancer.

In cases such as these, reaching out to the health provider for exercise recommendations is a good first step. This helps ensure that the workout is safe for the client and their medical condition. It also gives parameters for the physical activity, such as the form of exercise that’s okay and any intensity limitations.

Whether for yourself or your clients, it can be helpful to receive advanced training in this area. One option is to become a Certified Health Coach. This certification teaches you how to work with physical and mental fitness barriers. In addition to learning about some of the most common health conditions, you also gain the skills needed to help people with these conditions reach their fitness goals.

Featured Course

Certified Health Coach

ISSA's Health Coach certification is for personal trainers and other health professionals who want to help clients overcome physical and mental health barriers to achieve their optimal wellness.


  • Encyclopedia, M., & immunity, E. (2022). Exercise and immunity: MedlinePlus Medical Encyclopedia. Retrieved 20 September 2022, from

  • Barrett, B., Hayney, M. S., Muller, D., Rakel, D., Brown, R., Zgierska, A. E., Barlow, S., Hayer, S., Barnet, J. H., Torres, E. R., & Coe, C. L. (2018). Meditation or exercise for preventing acute respiratory infection (MEPARI-2): A randomized controlled trial. PLOS ONE, 13(6), e0197778.

  • Zhou, G., Liu, H., He, M. et al. Smoking, leisure-time exercise and frequency of self-reported common cold among the general population in northeastern China: a cross-sectional study. BMC Public Health 18, 294 (2018).

  • Physical Activity Prevents Chronic Disease. Centers for Disease Control and Prevention. (2020). Retrieved 20 September 2022, from

  • Cold remedies: What works, what doesn't. Mayo Clinic. (2022). Retrieved 20 September 2022, from

  • Stay Home When You Are Sick. Centers for Disease Control and Prevention. (2020). Retrieved 20 September 2022, from

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