Exercising When Sick

While exercising when sick is not recommended, there are certain instances where you can continue training at a reduced intensity.

For highly active individuals there are few things more frustrating than missing training due to colds and flu. This often means that many of us will still hit the road or gym when we’re feeling under the weather. Conventional wisdom dictates that we take it easy when our bodies are fighting an infection, but it does seem that we can continue to exercise in certain instances.

The general rule of thumb, which is shared by both exercise specialists and medical practitioners, is the “neck rule”. Simply stated, if you have an infection that affects you above the neck, such as an upper respiratory tract infection (URTI) that presents as a runny nose, nasal congestion, sneezing or a minor sore throat, you can still train, albeit at reduced intensity, duration and volume.

Stop exercising immediately if you experience:

– Chest tightness or pressure
– Trouble breathing or excessive shortness of breath
– Light-headedness or dizziness
– Difficulty with balance

A study published in the journal, Medicine & Science in Sports & Exercise*, found no difference in symptoms between participants who exercised after being infected with a rhinovirus than those who simply rested.

The study also found that there was no difference in the time it took to recover from the infection by the exercising and control groups. The researchers also reported that having a cold had no effect on either lung function or exercise capacity.

There are also those who believe that exercise can make you feel better when you are suffering from a mild URTI. While this feeling can be attributed to the release of endorphins, the fact that exercise increases the diameter of blood vessels and the respiratory tract my help to explain the alleviation of certain symptoms, like nasal congestion and lethargy, post-exercise.

There are still those who believe that exercising while sick can increase the severity and duration of a cold or flu. This seems to be most prevalent among athletes who continue to train at a high intensity or for longer than 90 minutes.

So, if you choose to exercise with a mild cold or flu, it’s important to listen to your body and make rational choices based on how you feel before, during and after training.

It is advised that you cease exercise and rest if your symptoms are “below the neck”. This can include chest congestion, coughing, an upset stomach, a fever, muscle or joint pain, or general fatigue.

The reasons for this are numerous. Most importantly, certain viruses can affect the heart, which could lead to serious complications or even death in certain instances. As exercise raises your core body temperature exercising with a fever could also lead to serious complications. Exercising with a fever of 38.3 degrees Celsius or higher is contraindicated as it can lead to kidney or liver failure.

Do not exercise if your symptoms include:

– Chest congestion

– Coughing and/or wheezing

– Fever

– Muscle aches

– Joint pain

– General fatigue

Studies conducted on animals that were infected with a systemic virus found that when they were forced to exercise with fever and pain their symptoms were exacerbated, prolonged, and sometimes became life-threatening. As such, the worst thing you can do with a severe illness or virus is try to “sweat it out” with exercise.

Avoiding colds and flu

People are mainly infected with common colds and flu through direct contact (touching). Germs are spread via common objects such as hands, door handles, treadmills, weights and computer keyboards. When we touch infected objects and then touch our mouth or nose with unwashed hands we become infected. It is less common that infections are transmitted via the air, which is why it is essential to wash your hands regularly.

Regular exercise also appears to boost the immune system, which can help to reduce the number of colds you get this winter. Adequately periodised, mild-to-moderate exercise has been shown to boost the number and aggressiveness of certain immune cells, like natural killer and T cells, by as much as 300%. Intense exercise, on the other hand, can reduce immunity, so plan your training appropriately to avoid being struck down by colds and flu this winter.

Written by: Pedro van Gaalen, Managing Editor
* Study directed by Thomas G. Weidner, Ph.D., director of athletic training programs at Ball State University in Indiana