Should You Exercise With a Cold?

The Effect of Exercise on Upper Respiratory Infections

woman stretching in cold weather
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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. Is it good or bad to exercise with a cold?

The quick answer to that question is, "It depends." 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.

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.

Mild vs. Strenuous Exercise When You Have a Cold

Whether or not you should exercise with a cold depends on several factors, but most important is the degree of exercise you are considering. Let's break this down into parts:

Intensive Exercise

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

Mild and Moderate Exercise

Whether you should engage in lesser levels of exercise also 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.
  • On the other hand, 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 intensive training

    Can Strenuous Exercise Raise Your Risk of Cold or Flu?

    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 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. As a result, heavy exercise can reduce the ability of our immune system's to attack foreign invaders, such as the viruses which cause the common cold and the flu.

    The Flu Shot and Exercise

    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.

    Prevention and/or Coping With Illness for Athletes

    Knowing the constraints on exercise with a cold listed above, contracting a cold or the flu can throw a wrench in your training program as an athlete.

    As noted earlier, 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:

    • Maintain a moderate exercise routine: When you are healthy, maintaining a moderate exercise program rather than exercising in spurts appears to reduce your risk of developing an upper respiratory infection.
    • Avoid over-training: Space vigorous workouts and race events as far apart as possible. Keep "within yourself" and don’t push beyond your ability to recover.
    • Eat a well-balanced diet: The immune system depends on many vitamins, minerals, and other nutrients for optimal function. While there is no good data to support supplementation beyond 100 percent of the Recommended Daily Allowances, eating a wide variety of foods rich in fruits and vegetables is most likely to give you what you need. A good rule of thumb is to eat 10 to15 calories per pound of "desired body weight." If your ideal weight is 170 lbs, then consume 1700 to 2550 calories a day (1700 for sedentary individuals and 2550 for extremely active types.)
    • Avoid rapid weight loss: Low-calorie diets, long-term fasting and rapid weight loss have been shown to impair immune function. Losing weight while training heavily is not good for the immune system.
    • 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.
    • 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.
    • Get a flu shot: Unless you have a reason not to get the flu shot, and especially if you have a weakened immune system, make sure to get your annual flu shot.
    • 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.
    • Limit alcohol intake: Alcohol can be dehydrating which, in turn, may decrease your resistance to bacteria.
    • Know your vitamin D level: Vitamin D deficiency reduces your ability to fight infections and the majority of the U.S. population is deficient.
    • Listen to your body: If you are feeling less than 100 percent, you will feel better and recover faster if you let yourself rest.

    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. Strenuous exercise should be avoided with a cold 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.

    Sources:

    Grande, A., Reid, H., Thomas, E., Nunan, D., and C. Foster. Exercise Prior to Influenza Incidence and Its Related Complications in Adutls. Cochrane Database of Systematic Reviews. 2016. 22(8):CD011857.

    Marineua, A., Jolliffe, D., Hooper, R. et al. Vitamin D Supplementation to Prevent Acute Respiratory Tract Infections: Systematic Review and Meta-Analysis of Individual Participant Data. BMJ. 2017. 356:i6583.

    Shaw, D., Merien, F., Braakhuis, A., and D. Dulson. T-Cells and Their Cytokine Production: The Anti-Inflammatory and Immunosuppressive Effects of Strenuous Exercise. Cytokine. 2017 Oct. 8. (Epub ahead of print).

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