Exercising when you are sick: is it good or not?

Stopping sports for days or even weeks is a difficult decision for many people. But when you have the flu or a fever, you have to know when to stop! We'll tell you why.

Exercise is great for preventing illness: immune cells circulate more easily when you move. Doing moderate activity like walking, cycling or running is said to reduce the risk of respiratory infections and other common illnesses by half. But what about exercising when you're sick? Is it recommended or should you avoid it?

You must know that Exercising while suffering from a simple cold would have no effect on the duration or severity of symptoms. In other words, if a person with a cold wants to continue their workouts, they are not at risk of getting injured any more than usual. But it will not help them heal any faster either!

Exercising when you are sick, but without a fever, is not totally contraindicated, although it is not strongly recommended. You can allow yourself to do a little physical exercise, depending on how we feel, our form of the day, etc. says sports medicine physician Dr. David Levine.

But in case of flu or other form of infection that causes a fever risingthis is a very bad idea. Sport is a form of physical stress which makes the immune system's job harder. Now, some people tend to think, “If I have a fever, I have to sweat.”

Yet when a person is ill, “they are already devoting a great deal of their energy to defend against disease. “If we impose physical exercise on top of that, we will increase energy expenditure, and we will go beyond his capacities,” reports Dr. David Levine.

The consequences are potentially cardiac: in fact, fever increases heart rate. “When you have a fever, your heart rate is higher than usual. Physical exertion will further increase the rate, which can quickly rise to a dangerous level – especially if the effort is prolonged,” explains the doctor.

Exercising with a fever also increases the risk of dehydration.

After being sick, you should not resume sport anyhow.

“Obviously, if I start running at a height that I had not reached before, I do not put myself in the best frame of mind. So, it all depends on what activity we do, at what intensity, for how long, etc.”, continues the doctor.

“If I have been sick for several days, I have had a fever, I still feel tired… I can possibly ask my doctor for advice, to know if I am able to resume my physical activity, with what progression, etc.”

Once the fever has gone, experts recommend to wait about a week before resuming exercise : Start with long walks, then resume moderate training sessions. If after a week you feel good, you can resume your usual training. But if you notice muscle pain or weaknessgive yourself a few extra days of rest. Don't hesitate to consult a doctor.