When It's OK to Work Out While Sick, According to MDs

To exercise or not to exercise: that is the question for a lot of us when we're feeling under the weather. For routine exercisers, it can be hard to break the habit, even when you're not feeling well; other times, it may feel like gentle yoga or a stroll outside could do us some good.When is it OK to work out while sick, and when should you skip it? Since it's summer cold season, to fill in the knowledge gaps, PS spoke with three MDs - a mix of sports medicine and infectious disease experts - to get definitive advice on how to approach exercise when you're sick.Experts Featured in This ArticleJennifer Luz, MD, is a board-certified sports medicine physiatrist at Boston Sports Performance Center.Brian Chow, MD, is an infectious disease physician at Tufts Medical Center.Sarah Eby, MD, PhD, is a Mass General Sports Medicine physician and assistant professor of physical medicine and rehabilitation at Harvard Medical School.Is It OK to Work Out While Sick? And does it matter if it's a stomach bug, flu, or a head cold?"A great general rule of thumb is to keep exercising if symptoms are 'above the neck,'" says Dr. Luz. For example, a head cold with symptoms like nasal congestion, runny eyes, or a mild headache may not be a problem, depending on how you feel; however, more major symptoms that occur in the chest or throughout the rest of the body, like a fever, body aches, difficulty breathing, coughing, wheezing, nausea, vomiting, and other flu symptoms, are a reason to avoid working out while sick. "Symptoms in these areas are a sign your body is trying to fight a more serious infection, and taking energy and resources away from that effort is likely to prolong your recovery," says Dr. Eby, who agrees with the "above the neck" rule.When you're sick, it's most important to listen to your body and rest; while sick, you'll need even more rest than usual to let your body fully recover, Dr. Luz says. If you put extra strain on your body from working out while sick, it'll likely take your body even longer to both heal from your illness as well as recover from the exercise you're doing.Is It Ever Helpful to Work Out While Sick?One of the many benefits of exercise is that it's good for your immune system, "but this is a long-term effect over time," Dr. Chow explains. "Exercising while sick does not necessarily make you get better faster, and it is perfectly fine to give yourself a pass if you're not feeling 100 percent." If you're worried about your training progress, remember that "you won't lose all of your fitness and strength by taking it easy (or off entirely) for a few days," Dr. Eby adds.However, if your symptoms are above the neck and you feel well enough to exercise, some mild to moderate exercise might actually help you feel a little better, as it can help clear congestion, says Dr. Eby. Dr. Luz adds that exercise can boost circulation, improve oxygen exchange (which could give you more energy), and stimulate your immune system.Still, rest is important, and you won't want to push it, even if you're feeling OK. Dr. Chow puts it succinctly: "If you're looking for a PR, it probably won't happen if you're sick."When You Should Absolutely Not Exercise While SickIf you have a fever, it's best to skip any physical activity. "A fever is also a sign that your body is diverting resources to fight off an infection, and it could be a sign that something more serious than a cold or the flu is going on," says Dr. Chow. "A fever is a marker of inflammation and physical stress in the body. We do not want to add additional physical stress to the body on top of this physiologic state," adds Dr. Luz.Additionally, you should avoid exercise if you're feeling dizzy or light-headed, Dr. Eby says. And if you have heart or lung problems, you should discuss exercise when sick with your doctor, as illnesses like colds and pneumonia can place additional stress on those important organs, Dr. Chow adds.If You Are Going to Work Out, Follow These RecommendationsIf you're going to exercise while sick, all three doctors recommend lower-intensity exercise, like walking and yoga, over high-intensity workouts. "High-intensity cardio or high-intensity weight lifting is generally not recommended," Dr. Luz says. And if you do need to do those types of workouts for whatever reason, Dr. Eby recommends starting at a lower intensity than usual, factoring in rest breaks as needed, and shortening your workout. It's all about listening to your body, says Dr. Chow."Take extra care in warm up, cool down, and stretching to help the body recover while it is under additional stress from an illness," Dr. Luz adds.Hydration is also incredibly important, all three doctors say, as both illness and exercise can dehydrate you; and so is getting plenty of sleep for recovery. And for the sake of others, try to keep your germs to yourself. Work out at home if you're feeling up to it, and if you do need or really want to hit the gym, be sure to wash your hands and exercise caution (no pun intended) to avoid getting others sick, says Dr. Eby. Practice good gym etiquette: wipe down equipment, avoid touching your face and eyes, and carry hand sanitizer, the doctors say. When cleaning equipment, you should wipe down anything that your body touches, and allow the area to dry before using it, says Dr. Chow. Dr. Eby recommends avoiding group classes out of consideration for others if you're contagious. Kaley Rohlinger is a freelance writer for PS who focuses on health, fitness, food, and lifestyle content. She has a background in the marketing and communications industry and has written for PS for over four years. Related: Is It the Flu, COVID-19, or a Common Cold?