The question:Is it OK to exercise when I’m sick?
The human body is a miracle of integrated structure and function in so many ways. One of the more practical means of connecting function and feasibility is the idea that if something hurts, don’t do it. For example, if you sprain your ankle playing a sport, the swelling and pain that accompany the injury are your body’s way of telling you to rest and allow yourself to heal.
Managing the activities of daily life during an illness is not all that different. Because your body is generally working harder to fight off the infection, any additional stress on your system from exercise may, rather than boost your immune system, impair healing or prolong recovery time from the illness.
Here are some practical examples of how this works:
This bacterial infection of the soft tissues at the back of your throat generally causes pain, fever, swollen glands and a general feeling of malaise. You may not have much of an appetite and may only be able to drink liquids due to the pain. Any sort of rigorous exercise — including running, weight lifting, spinning or team sports — may increase your overall fatigue, raise the temperature of an already feverish body and cause dehydration, since your ability to take fluids is compromised.
This infection of your paranasal sinuses is often accompanied by headache, cough from post-nasal drip and difficulty breathing through your nose from congestion. The elevation in heart rate and blood pressure that normally occurs with any type of cardio exercise may make the throbbing in your head from a sinus infection worse, and because you can’t efficiently breathe through your nose may make it more challenging to keep from getting winded.
Whether from a bacterial infection or, more commonly, a virus, the inflammation of your airways that results in a hacking dry cough may only be made worse by the work of breathing during exercise. You may end up with wheezing and chest congestion due to cold outdoor air being raked over your already inflamed bronchial tubes, and a cough that is worse than ever.
Do you really want to be “that person” at the gym who is coughing, sneezing and wiping mucus all over the equipment, potentially infecting everyone else?
On the whole, if your illness impairs your daily activities (work, sleep, eating) you probably shouldn't exercise. Don’t be afraid to take a few sick days off from your workout. The benefit of resting to your general health is likely more useful than any short- or long-term gains to be had from exercising while ill.