Should You Exercise With a Cold?

woman stretching in cold weather

The average adult has two to three upper respiratory infections each year and many athletes wonder if they should continue their training routine when sick. Even non-athletes may struggle on whether they should continue to exercise with the cold or flu.

Whether or not it is a good idea to work out when you are sick depends upon a variety of factors. Let's take a look at the effect of mild, moderate, and extreme exercise on the cold or flu so you know whether to put on your running shoes next time you begin to sniffle.

The Effect of Exercise on Illness

At first glance, many people may be surprised by the question of exercising with a cold. After all, haven't we been led to believe that exercise is good for just about anything? It's important to note that the question about exercising with a cold isn't a simple question. What people consider exercise can vary from a 15-minute gentle walk to running a marathon.

Whether or not you should exercise with a cold depends on several factors, but most important is the intensity of exercise you are considering. Vigorous exercise has a different effect on your body than mild or moderate exercise.

Mild and Moderate Exercise

Whether you should engage in mild or moderate levels of exercise needs to be broken down, and depends on the extent of your symptoms. While research is limited, most experts recommend that if your symptoms are above the neck and you have no fever, exercise is probably safe.

If you have symptoms or signs of a cold or the flu such as a fever, extreme tiredness, muscle aches, or swollen lymph glands, it's recommended that you take at least two weeks off before you resume vigorous (intensive) training.

Vigorous Exercise

When you are sick, your immune system is already challenged. Heavy exercise can reduce immunity and consequently your ability to fight illnesses (such as the cold and flu) even further.

Most researchers recommend that high-intensity exercise be postponed until a few days after cold symptoms have gone away.

Exercise and Your Risk of Illness

Not only is it unwise to exercise strenuously while you have a cold or flu, but exhaustive exercise may increase your chance of catching a cold or the flu in the first place. One of the "big guns" in our immune system are T-cells (T lymphocytes.) There are many different types of T cells, however, with some being our first line of defense against infection, and some moderating the immune response.​

Heavy exercise appears to both reduce the number of type I T-cells in the blood (our SWAT team) and increase the number of "regulatory" T-cells.

Heavy exercise can reduce the ability of our immune system to attack foreign invaders, such as the viruses which cause the common cold and the flu.

In learning about the relationship between catching the flu and coping with the flu, you may have wondered whether or not exercise affects the flu shot. According to a 2017 study, exercise was neither beneficial or harmful after receiving a flu shot.

Illness Prevention for Athletes

Given the constraints on exercise with a cold, contracting a cold or the flu can throw a wrench in your training program as an athlete. Intensive exercise should be avoided not just until you are feeling a little better, but until your symptoms are gone completely. Even mild to moderate exercise should be reduced if you have a fever, fatigue, swollen glands, or symptoms below your neck such as body aches.

So what can you do to reduce your risk of getting ill in the first place or at least hasten your recovery when you do catch a cold or flu? Try these:

  • Avoid over-training: Space vigorous workouts and race events as far apart as possible. Don’t push beyond your ability to recover.
  • Avoid rapid weight loss: Low-calorie diets, long-term fasting, and rapid weight loss can impair immune function. A good rule is to eat 10 to 15 calories per pound of desired body weight. If your ideal weight is 170 pounds, consume 1700 to 2550 calories a day (1700 for sedentary individuals and 2550 for extremely active types).
  • Don't touch your eyes, nose, or mouth: Most bacteria and viruses are spread from a surface to your hands to your face, not by air.
  • Drink more water: In the fall and winter, it's easy to overlook your thirst and get dehydrated. Make sure you consume eight glasses of water daily.
  • Eat a well-balanced diet: The immune system depends on many vitamins, minerals, and other nutrients for optimal function. Eating a wide variety of foods rich in fruits and vegetables is most likely to give you what you need.
  • Get a flu shot: Especially if you have a weakened immune system, make sure to get your annual flu shot.
  • Get adequate sleep: Major sleep disruption (defined as getting three hours less sleep than normal) has been linked to immune suppression. If you are struggling with your sleep, evaluate your sleep hygiene or talk to your doctor.
  • Know your vitamin D level: Vitamin D deficiency reduces your ability to fight infections and the majority of the U.S. population is deficient.
  • Limit alcohol intake: Alcohol can be dehydrating, which, in turn, may decrease your resistance to bacteria.
  • Listen to your body: If you are feeling less than 100%, you will feel better and recover faster if you rest.
  • Maintain a moderate exercise routine: When you are healthy, maintaining a regular, moderate exercise program rather than exercising in spurts appears to reduce your risk of developing an upper respiratory infection.
  • Wash your hands frequently: Though washing your hands seems obvious to most people, the majority of people do not follow the health care professionals method of washing hands that's been shown to reduce infection risk. Don't forget your fingernails. Washing your hands is often your single best method of prevention.

A Word From Verywell

While exercise, in general, is helpful in many ways, overdoing it can both increase your risk of developing a cold and interfere with your recovery when you do get ill. Avoid strenuous exercise until all of your symptoms have resolved.

For mild colds, mild to moderate exercise is probably OK. If you have a fever, swollen glands, fatigue, or muscle aches, however, you should refrain from exercise until your "below the neck" symptoms are gone, and should avoid strenuous exercise for around two weeks.

Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

By Elizabeth Quinn, MS
Elizabeth Quinn is an exercise physiologist, sports medicine writer, and fitness consultant for corporate wellness and rehabilitation clinics.