Why can’t you exercise when you’re sick?

PhD in Medicine, trailrunner, founder and coach of the ERA running club

How does sport affect the body during illness? Does it help to cope with a cold?

Let’s make it clear right away – by the word “illness” we mean an acute respiratory infection without complications, not, say, acute appendicitis or hypertensive crisis.

Any infection represents a load on the body. Both due to a more or less pronounced inflammatory reaction accompanying the infectious process, and due to intoxication, that is, poisoning of the body by the decay products of the pathogen (bacterial cells or viral bodies), as well as its own cells of the immune system, the epithelium of the respiratory tract and other tissues captured by the infection.

The infection results in common symptoms known to all: fever, weakness, fatigue, muscle aches, chills, excessive sweating, drowsiness or insomnia, headache, appetite disorders. To these, local symptoms are added: sore throat, nasal congestion, runny nose, cough, sometimes tearing in the eyes and lacrimation.

It is clear that in such a painful condition, additional physical activity is perceived more difficult and its benefits are doubtful. Let’s understand why.

What happens in the body during illness?

The resources of the body at this time are spent on destruction of the causative agent and restoration of damaged cells and tissues. And for adaptation to the training load and the development of physical qualities (strength, speed, flexibility, endurance, agility) will be little left – here operate the laws of biological expediency, which can not be cheated or bypassed.

We do not know how to “strengthen immunity”, today medicine can only suppress it, and quite crudely at that. It is still possible – and necessary – to make efforts to prevent disease.

Is it possible to exercise during a cold? Why?

During the acute phase of a respiratory infection (about one week, while the manifestations of the disease are increasing and staying at their peak), physical activity should be limited, otherwise there is a risk of harming yourself.

In addition, going out for training in the acute phase of the infectious process, you are an active spreader of infection. This is also not good.

The same publication says (and this is confirmed by my own practice) that the time and speed of physical fitness recovery can vary greatly from person to person. Sometimes the consequences of the infection – significant regression of indicators, low exercise tolerance, fatigue – continue for several months after the disappearance of symptoms. The general recommendation in this case is to gradually increase the load without trying to return to the previous state “in one jump”.

Do you take a break from training when you are sick? Or do you go to the gym no matter what?