Exercising When Sick: Should You or Shouldn’t You?

The answer depends on what ails you, experts tell WebMD. For example, exercising with a cold may be OK, but if you’ve got a fever, hitting the gym is a definite no-no.

Fever is the limiting factor, says Lewis G. Maharam, MD, a New York City-based sports medicine expert. “The danger is exercising and raising your body temperature internally if you already have a fever, because that can make you even sicker,” he tells WebMD. If you have a fever greater than 101 degrees Fahrenheit, sit this one out.

Maharam’s rule of thumb for exercising when sick? “Do what you can do, and if you can’t do it, then don’t,” he says. “Most people who are fit tend to feel worse if they stop their exercise, but if you have got a bad case of the flu and can’t lift your head off the pillow, then chances are you won’t want to go run around the block.”

Personal trainer and exercise physiotherapist Geralyn Coopersmith, senior manager of the Equinox Fitness Training Institute in New York, has this to add: “The general rule is that if it is just a little sniffle and you take some medications and don’t feel so sick, it’s OK to work out. But if you have any bronchial tightness, it’s not advisable to be working out.”

You really need to know your limits, she says. “If you are feeling kind of bad, you may want to consider a walk instead of a run. Take the intensity down or do a regenerative activity like yoga or Pilates because if you don’t feel great, it may not be the best day to do your sprints,” says Coopersmith, the author of Fit and Female: The Perfect Fitness and Nutrition Game Plan for Your Unique Body Type.

“A neck check is a way to determine your level of activity during a respiratory illness,” adds Neil Schachter, MD, medical director of respiratory care at Mount Sinai Medical Center in New York. “If your symptoms are above the neck, including a sore throat, nasal congestion, sneezing, and tearing eyes, then it’s OK to exercise,” he says. “If your symptoms are below the neck, such as coughing, body aches, fever, and fatigue, then it’s time to hang up the running shoes until these symptoms subside.”

Prevention Prescription

The best way to avoid the problem is not to get sick in the first place.

Exercise in general can help boost your body’s natural defenses against illness and infection, Schachter says. “Thirty minutes of regular exercise three to four times a week has been shown to raise immunity by raising levels of T cells, which are one of the body’s first defenses against infection. However, intense 90-minute training sessions like those done by elite athletes can actually lower immunity.”

Gym Etiquette When Exercising With a Cold

It’s one thing if you decide to exercise when sick, but how do you keep from spreading it to others in the gym? And what about you if they are the ones exercising with a cold?

“Be careful that you are not blowing your nose constantly. And you should be using a towel and putting it down on every surface you touch and wiping it off when you are done,” says Equinox’s Coopersmith.

“The value of hand washing cannot be overstated,” Schachter says. “I recommend washing hands before and after using the restroom, before meals, after using public transportation, and after returning home from school or work.”

Also carry alcohol-based hand sanitizer gel in your gym bag to use when you realize that you have come into contact with someone who is sneezing or coughing.