Should You Work Out When You're Sick? Here's How to Decide, According to Doctors
These six signs indicate that you should skip exercise and prioritize rest instead.
By Blake Bakkila•
Should You Exercise When You’re Sick?
When Should You Avoid Working Out?
When Is It Safe to Work Out if You’re Sick?
Tips for Exercising While Sick
When to Return to Your Regular Workout Routine
The Takeaway
Nothing throws a wrench in your workout routine quite like getting a cold. If we’re talking about the common cold, that’s a mild upper respiratory illness that goes away relatively quickly, according to the Centers for Disease Control and Prevention (CDC). You might experience congestion, a sore throat, sneezing, or even a fever. Depending on your specific symptoms, you might conclude that exercise won’t happen for a while. Sometimes, however, you may feel well enough to get moving.
When you’re feeling under the weather, getting some fresh air and a little exercise could seem like a good idea to promote your recovery. But what about other illnesses or symptoms? When can you exercise when you’re sick, and when should you prioritize rest? We spoke with experts to get to the bottom of it.
Should You Exercise When You’re Sick?
While it’s not the easiest question to answer, experts agree that whether you should work out when sick or not really comes down to your specific symptoms. For instance, dealing with a mild cough requires a different recovery compared to experiencing the flu, COVID-19, or other contagious diseases.
“While exercise has numerous health benefits, it's essential to listen to your body,” says Shoshana Ungerleider, MD, a board-certified internal medicine physician at Crossover Health in San Francisco. “If you're feeling slightly under the weather but overall OK, light to moderate exercise might be permissible. However, if you're feeling genuinely unwell, it's often best to give your body the rest it needs.”
So, how do you know whether your specific illness warrants a rest day or permits a quick trip to the gym? To answer that, we’ll first need to dig into when not to exercise when you’re sick.
When Should You Avoid Working Out?
As you’re staring at your workout clothes, you may wonder when it’s the wrong time to break a sweat. In some cases, your symptoms can serve as your body sending you “warning signs,” explains Sean Rockett, MD, a board-certified orthopedic surgeon and senior partner of Orthopedics New England in Natick, Massachusetts.
Here are some signs that you should skip your workout, plus key insights from Dr. Rockett and Dr. Ungerleider:
Fever: If you have a fever, working out can raise your internal body temperature even more, causing more harm, Dr. Ungerleider explains. (It’s also a myth that you can “sweat out” a fever.) Having a fever could also mean you’re sick with the flu, COVID-19, or another infectious disease, which can spread to others in your local gym or any other workout facility. Shaking, chills, and sweats also fall into the “warning signs” category outlined by Dr. Rockett.
Chest congestion, wheezing, or shortness of breath: All of these unpleasant feelings are considered “below the neck” symptoms, which can make it harder to breathe, according to Dr. Ungerleider. Because these aren’t symptoms you would experience during a typical workout, you should avoid exercising, as it’ll likely make things worse.
Body aches: Widespread aches in your body could be a sign of a more systemic illness, Dr. Ungerleider says. And if your body is in pain already, you won’t be able to perform exercises safely or effectively.
Diarrhea or vomiting: While you’re recovering from an illness, your body undergoes fluid shifts, explains Dr. Rockett. If you’re experiencing diarrhea or vomiting, that’s a clear indication that exercising can only make you more dehydrated and should be a no-go. It’s also recommended to avoid swimming, in particular, if you have diarrhea. Per the CDC, swimmers who have crypto (a parasite that causes the diarrheal disease cryptosporidiosis) should stay out of the pool until two weeks after the diarrhea has stopped.
Lightheadedness or dizziness: Dr. Rockett says this is yet another sign that you’re not quite ready to exercise. Like diarrhea or vomiting, these symptoms could also be your body telling you that you’re dehydrated and need to improve your fluid levels before getting active.
Fatigue: If you’re feeling tired and sluggish, that’s another sign to skip out on your workout when you’re sick. Fatigue likely indicates that your body needs a break, so it’s smart to prioritize rest at this time. Fitness beginners and experienced athletes alike can often use a rest day (or two, or more).
These are only a handful of the symptoms that signal you should avoid your regular exercise routine. If you’re experiencing any other symptoms that are tied to contagious diseases, you should also stay home and recover until you feel better. And remember, it's smart to check in with your doctor if you're not sure whether or not working out when sick is an option for you.
When Is It Safe to Work Out if You’re Sick?
It’s appropriate to exercise if you’ve just been dealing with a mild cold, “especially those with symptoms limited to above the neck, like a runny nose or sneezing,” Dr. Ungerleider says. “If you're experiencing these milder symptoms and still feel like working out, you can, but you should reduce the intensity and duration of your exercise.”
Dr. Rockett agrees, noting that before you dive back into exercise, you should also simply start feeling like yourself again. By listening to your body, you can better determine if it’s safe to exercise or not when you’re sick. “Start off at maybe 25 percent of your normal duration or intensity, and then work your way back up,” he recommends, explaining how you can incrementally increase your exercise duration or intensity to 50 percent, 75 percent, and so on over the next few days.
Depending on your symptoms, exercising while sick might even aid in your recovery. For instance, Dr. Rockett notes that if you're experiencing minor head congestion, working out may provide relief, as it can help open up nasal passages.
All that said, if you had (or still have) a fever, experts say you aren’t cleared for a workout quite yet. You should wait a few days after your fever has broken before resuming exercise, according to NYU Langone Health.
Tips for Exercising While Sick
Imagine this: Your workout clothes are on and you’re finally feeling ready to get active again. There’s excitement in this moment, but it’s also understandable to have some trepidation about jumping back into exercise after feeling under the weather.
These conflicting emotions are exactly why it’s smart to start at a lower intensity and/or duration, as Dr. Ungerleider and Dr. Rockett both recommend. Here are a few other pro tips to keep in mind as you’re getting back into your regular workout routine:
1. Avoid Working Out in Public or Taking Group Classes
It might be tempting to go to your local gym or favorite group exercise class, but for the safety of others exercising near you, it’s best to avoid these spaces until you’ve fully recovered. If you decide to do a solo workout outside instead, just make sure you have the appropriate clothing (i.e. wear extra layers if it’s cold out).
2. Start With a Low-Intensity Workout
Beyond lowering your specific workout intensity level, you can also choose an exercise that doesn’t push you too hard. “Consider walking instead of running, or doing a gentle yoga session rather than a high-intensity class,” Dr. Ungerleider says. (Psst: You can enjoy all of those activities on the Peloton App!) There’s also good news for those with a Bike: “A stationary bike and Peloton work is great because you're seated and not having to do a lot of jumping or twisting or turning,” adds Dr. Rockett.
3. Stay Hydrated
Water is your BFF with this first exercise back. Your body likely needs extra fluids, so take as many breaks as you need to hydrate.
That said, don’t overdo it: If you start your workout and have “a severe headache or nausea or feeling like you're vomiting—I wouldn't push yourself that hard,” Dr. Rockett says.
4. Listen to Your Body
At the end of the day, your body will let you know if it’s not time to hop back into exercising. “If you start feeling worse, stop immediately,” Dr. Ungerleider advises.
By factoring in all of these considerations, you should be both prepared and motivated to return to your regularly scheduled programming.
When to Return to Your Regular Workout Routine
We’ve discussed how starting at 25 percent of your typical exercise intensity or duration is best as you’re coming back from sickness, but when can you return to 100 percent? It’s pretty simple: It’ll be clear that you’re ready for 100 percent when you’re feeling 100 percent.
Again, it also goes back to what illness you’re working through. “When your symptoms have significantly improved or resolved, and you feel close to your normal energy levels, you can consider returning to your regular exercise routine,” Dr. Ungerleider says. “However, it's essential to ease back in. Gradually ramp up your intensity and duration over several days to ensure you don't overtax your body.”
This rule generally applies to those who’ve experienced a mild cold or illness, and it should only take a few days before you’re back to feeling and performing close to or at 100 percent. But if you're recovering from something a bit more severe, you'll want to consult a healthcare practitioner first, especially if you’re feverish or experiencing vomiting or diarrhea. Having the go-ahead from your doctor will also make you more confident about adding your favorite workouts back on the calendar.
The Takeaway
Getting sick isn’t fun or easy for anyone. You may need to take time off work, skip out on activities with loved ones, and of course, avoid exercising. While working out can often make you feel better in your recovery, it could also worsen your current symptoms. By listening to your body and evaluating these symptoms, you can hopefully find yourself feeling relatively “normal” and ready for your next workout before too long. If you have any other concerns or more severe symptoms, prioritize rest and reach out to your doctor, if necessary. And remember: walk, don’t run, on your road to recovery. You certainly won’t regret being gentle with yourself as you ease back into your workout routine.
This content is for informational and educational purposes only and does not constitute individualized advice. It is not intended to replace professional medical evaluation, diagnosis, or treatment. Seek the advice of your physician for questions you may have regarding your health or a medical condition. If you are having a medical emergency, call your physician or 911 immediately.
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