Excercising When Sick

On belay! More than any other, this brief statement says succinctly and clearly, “I’m properly equipped, I’m in position, I’m prepared, you can trust me.”

When you accept advice about your health and safety, you just as directly place your trust in someone else. If your telemark instructor says a particular binding is “best”, you rely on him to have personal knowledge of a broad range of equipment, to have used this equipment under conditions similar to what you will encounter, and to place your interests above any personal gain he may experience in making the statement.

In medicine, we are supposed to rely on scientific tests to provide the evidence that forms the foundation for what we know and how we act. Unfortunately, a surprising amount of health-related advice is opinion and not truly evidence-based. As a wise consumer of health care and health-related information, you should get in the habit of asking “What’s the evidence for that statement?” Be prepared for the evidence and the consequent best course of action to change over time.

When I make recommendations to my patients, I try to use the current best evidence on the subject. The evidence on ‘Exercising When You’re Sick’ is mostly indirect and inferential, so read it and take this advice warily.

There is pretty good evidence that immune response is decreased for a period of hours after intense exertion. There is fairly solid evidence that regular, moderate exercise enhances overall immune system function and that persistent, peak exercise impairs overall immune function. There is limited evidence that modest exercise does not result in harm to people who are mildly sick. There is speculative evidence that exercise may increase the chance for rare but serious heart complications from viral infections and that hypothermia may increase the risk of complicating pneumonia.

Expert opinion on exercising when you are sick comes in two flavors:
1.Don’t do it. You won’t benefit from the exercise and if you lose some conditioning during the illness you will gain it back quickly.
2.Look at the specifics of the illness and respond accordingly.

In my personal opinion, the first one ignores the passion and persistence of most athletes and underestimates the time needed to regain pre-illness conditioning. As for the second premise, we do not have the evidence to be able to tell you reliably how to do this, but there is reasonable agreement among experts. What follows is the consensus of opinions on exercising when sick.

Assess the location of the illness. If the symptoms are primarily ‘above the neck’, then modest exercise is probably safe. If you have a stuffy head, a runny nose, or a mild sore throat, you’re above the neck. If you have a cough, vomiting or diarrhea, you’re below the neck and should forego your exercise.

Assess the severity. If you have a fever, body aches, and chills—if you feel like crawling back into bed and sleeping for a week—you’re too sick to exercise. If your resting pulse is higher than usual or if you have a severe cough with chest pain and shortness of breath, stay home.

Assess the type of exercise. If you have a contagious illness, you shouldn’t be going to the gym and sharing the germs with your friends. If you’re going on a ski traverse of Yellowstone, even a minor illness should delay your plans.

Modify the intensity of the exercise. If you’re going to cycle when you have a cold, the wise course is to ride shorter and slower, and do your flat ride instead of the one with all the hills. When sick, your exercise should involve fewer reps, lower weight, less speed, reduced intensity… and gradually build back to usual.

Modify your intake. You will need more fluids than usual to stay properly hydrated and manage secretions. Consider taking extra vitamin C to reduce oxidative stress. Prior to exercise, fueling up with sugars or simple carbohydrates may reduce the temporary negative effect on your immune system.

In the absence of reliable scientific evidence, my advice is old-fashioned Calvinist moderation. It’s not fancy, but it’s wise. Trust me.