Should You Exercise When You're Sick?

Whether or not to exercise when you are sick depends on your symptoms, how you feel, and the intensity of your workout.

There aren't any concrete rules for when it's OK to exercise with a cold or cough, but there are some general guidelines. Working out should be fine if your symptoms are above the neck and you feel up to it. Below-the-neck symptoms, however, are a sign your body needs rest.

This article discusses whether or not you should exercise when you are sick. It looks at common cold and flu symptoms to explain when it is safe to exercise and when you should not exercise when you are sick.

The "Neck Check"

There isn't a lot of research on exercising when you are sick. However, healthcare providers have some common guidelines they use to advise their patients who worry about hitting the gym when they're under the weather.

One such guideline, based on a 1996 study, is called the "neck check:"

• If symptoms are all above the neck (sniffles, sneezing, etc.), you're probably fine to work out.
• If symptoms are below the neck (vomiting, coughing, fever, body aches, etc.), you should probably not exercise.

However, that advice isn't clear-cut or supported by further study, so it helps to know more about specific symptoms and how they could impact you while working out.

Gentle Exercise for Fatigue

Your energy level is one of the best indicators of whether or not you should be working out.

If you're fatigued and feeling rundown, let your body rest and recover before you begin exercising again.

If you have a simple cold and your energy level is pretty normal, it's probably OK to exercise.

The intensity of the workout is also something to consider. A mellow yoga class or walk should be OK if you are sick, but you might want to skip the advanced cardio class.

Avoid Strenuous Exercise With a Fever

This one symptom comes with crystal clear advice: If you have a fever, stay home. Research shows that strenuous exercise with a fever can make you sicker—so much that it increases the likelihood of death in animal studies.

The reasons for that are many:

• Fever increases fluid loss and dehydration.
• Exercise, in addition to fever, can raise your body temperature to a dangerous level.
• Fever saps your energy and lowers your muscle strength and endurance.

It’s usually not a hard decision to forgo exercise when you have a fever—your bed is likely calling your name much louder than the gym.​

Exercising With a Cough

Coughs can be a little more tricky than fevers when it comes to deciding whether or not to exercise. It depends on the type of cough and your other symptoms.

Working out with a phlegmy cough is different than lifting weights with a mild and dry cough.

According to conventional advice, the neck check applies:

• An occasional dry cough: Continue your exercise routine, if you feel up to it.
• A moderate cough: Stick to light activity, if you feel up to it.
• A frequent or productive cough: Do not work out; rest until your symptoms improve.

A heavy cough interferes with your ability to breathe. A workout that raises your heart rate requires more oxygen—and that's difficult to do when you are coughing.

If you decide to run with a cough, listen to your body. If you struggle to get enough air, take a break. Your body needs rest to heal. When in doubt, check with your healthcare provider.

Running with a Runny Nose

Congestion and runny noses are above-the-neck symptoms. You should still be able to exercise with a head cold, provided you do not have other symptoms.

However, if you also have a cough, fever, or are feeling rundown, you should take a rest day.

If you have significant difficulty breathing due to the congestion, avoid intense workouts and stick to gentle exercise or rest until you're feeling better.

What If You're an Athlete?

If you work out all the time and you're in great shape, you might think you're an exception—that your body can handle the stress of exercise even though you're ill.

Again, research doesn't have definitive answers, but consider these facts:

• Much of the research that has been done on exercising while ill has been done on athletes, so the suggested restrictions definitely apply to you.
• Exercising while ill can increase your risk of an injury, and an injury is likely to take you out of the game for a lot longer than a passing illness.

Fortunately, studies show people who exercise regularly are less likely to catch colds and get sick in general.

Summary

Whether you should exercise when you're sick depends on your symptoms. Symptoms above the neck are usually OK to work out with. Body-wide or below-the-neck symptoms, like fever and cough, indicate your body needs rest.

If you don't exercise regularly, it's probably best to wait until you're healthy before starting a fitness routine. If you aren't sure, check with your healthcare provider.