Serious Question: Is It Safe to Exercise When You're Sick?

woman exercising


Staying motivated to work out can be tricky. That endorphin-rush to jumpstart your day–or to cap a long one—can feel amazing. But there are also those days when just the idea of putting on a sports bra can feel like a grueling chore. And what if you're feeling under the weather—should you push through or sit it out? We tapped a sports medicine doctor, fitness expert, and registered dietitian for advice on whether or not to exercise when sick. Spoiler alert: the takeaway is that it all depends on what ails you.

Ahead, we sift through fact and fiction and rely on science and medicine to help you decide whether you should sweat through or skip your workout.

When Is It Safe to Exercise When You’re Sick?

Health experts advise following the "neck check" rule for exercising. If symptoms are confined to above the neck, such as a runny nose, nasal congestion, or sore throat, you may continue to exercise lightly, for about 10 to 15 minutes per day as long as you feel up to it. But, if you have symptoms like fever, body aches, chest congestion, nausea, and diarrhea, you should skip your workout routine and allow your body to rest.

"Listen to your body," says Jessalynn Adam, MD, a board-certified physician specializing in primary care sports medicine. "You don’t have to be captive to your workout plan." In fact, she says pushing through when you're feeling lethargic can have unintended consequences, causing more harm than good. “Your body might be trying to tell you that you’re truly ill or lethargic and rundown. So back off." She explains that when your immune system is compromised, you won’t be able to effectively train anyway. "You don’t want to injure yourself by pushing."

There’s a difference between feeling unmotivated to work out and not having the energy to exercise because your immune system is compromised. "I usually give myself five to ten minutes to settle in," says Adam. "There isn’t an evidence-based response, but if I’m really struggling and I don’t want to be there, I know within the first five to ten minutes and I call it a day." Being flexible with your workout goals is key to maintaining optimal health. It’s important to be clear-headed about your fitness routine, especially if you’re feeling like your immunity is compromised. 

When to Give It a Rest

You definitely want to bench your workout for more severe symptoms like a fever, a stomach bug, or a cough that has mucus," according to Tony Castillo, RD. "If you have a runny nose, stuffy nose, or sore throat, it can make working out harder," he says. Health experts agree that there’s no medical science behind sweating out a fever or toxins. Your body’s raised temperature "is a signal you need to take a break," says Adam. In fact, excessive sweating might end up leaving you dehydrated and at-risk for further illness and injury. "Your body is over 60% water, and when you're sick, your body is not at optimal performance," says Castillo. Plus, your body doesn’t sweat out toxins—that’s a process of the kidneys and liver. 

The Best Types of Exercises for When You’re Under the Weather


Adam says that there is potential value in moving when you're feeling rundown, as exercise can be energizing. However, think of this more as movement than exertion. “You could do something low impact and low intensity like yoga and strengthening pilates.," she explains. A lot also depends on your baseline fitness level. "If you’re a runner, go for a short walk," says Adam, reiterating that now is not the time to train.

"You’ll want to avoid anything high intensity," concurs fitness expert and personal trainer, Miriam Fried. "It’s not going to be the time to do HIIT workouts, test out a personal record, or do anything overly taxing to the central nervous system."

Adam advises you consult the Borg Scale of Perceived Exertion, a resource created by Gunnar Borg, MD, which helps calculate estimated heart rate for specific levels of physical activity based on your level of fitness. 

When to Resume Your Routine

Once you've recovered, give yourself a day or two to get back in the swing of things before going full-throttle with your workout. "I would recommend a low intensity cardiovascular workout (steady walk or walking pace on a cardio machine of choice), light resistance training using 50% to 60% of your normal weight, or a gentle yoga flow," says Fried. Remember, the goal is to recover before challenging the body to exert energy. 

Additionally, take care to stay on top of your hydration game. Castillo says, "Being hydrated can help you avoid cramps, headaches, nausea, and even injury."

As people continue to practice social distancing, communal gyms aren’t seeing any action. But you should still practice gym etiquette at home to maintain a healthy environment, especially if you’re fighting an illness. It’s a good habit to wipe down equipment before and after use, says Fried and keep your workout area hygienic. 

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