BY THE OPTIMIST DAILY EDITORIAL TEAM

When you’re sniffling, sneezing, or just feeling a little off, it can be tempting to power through your usual workout. After all, isn’t exercise good for your immune system? But as cold and flu season ramps up, it’s worth asking: should you really hit the gym when you’re sick?

To help you decide when to lace up your sneakers and when to crawl back under the covers, three medical experts reveal what they want you to know: Dr. Jennifer Luz, a sports medicine specialist; Dr. Brian Chow, an infectious disease expert; and Dr. Sarah Eby, a Mass General sports medicine physician.

The “above the neck” rule: your go-to sick-day workout guide

If your symptoms are limited to the head and neck, like a runny nose, congestion, or a mild headache, you might be fine to squeeze in a gentle workout. “A great general rule of thumb is to keep exercising if symptoms are ‘above the neck,'” says Dr. Luz.

However, anything that affects your chest or the rest of your body is a clear red flag. “A fever, body aches, fatigue, cough, nausea—these are signs your body is working hard to fight off something more serious,” explains Dr. Eby. “Adding a workout into the mix only takes energy away from that recovery process.”

Why rest is your best friend when you feel awful

Even mild illnesses call for more rest than usual. “Recovery takes priority,” says Dr. Luz. “If you push through and exercise anyway, you could extend the duration of your illness and delay your body’s ability to recover from both the virus and the workout.”

Plus, Dr. Chow reminds us that the immune-boosting benefits of exercise are long-term. “Exercising while sick doesn’t necessarily help you get better faster,” he says. “It’s okay to take a few days off.”

The rare times a workout can actually help

That said, if your illness is mild and you’re feeling up to it, a little movement might actually help. “Gentle exercise can help clear congestion and improve circulation,” says Dr. Eby. “You might even feel more energized afterward.”

Dr. Luz agrees: “Boosting oxygen exchange and stimulating your immune system with light movement can be beneficial. Just don’t expect to hit any personal records.”

When you should definitely skip the gym

Fever? Stay home. “A fever is a major sign your body is in full-on fight mode,” says Dr. Chow. “Exercise only adds more stress.”

Other times to skip the workout include dizziness, chest congestion, shortness of breath, or if you have a history of heart or lung issues. “In those cases, talk to your doctor before resuming physical activity,” says Dr. Eby.

If you do exercise while sick, follow these expert tips

If you’re cleared to move, go for low-impact activities like walking or yoga. “Skip high-intensity workouts until you’re fully recovered,” advises Dr. Luz.

All three doctors stress the importance of:

• Hydration
• Quality sleep
• A slow, mindful warm-up and cool-down
• Listening to your body and taking breaks

And let’s not forget the germ factor. “If you’re contagious, be considerate,” says Dr. Eby. “Work out at home or skip group classes. And if you must go to the gym, wash your hands, wipe down equipment, and avoid touching your face.”

“When cleaning equipment, wipe down any area your body touches and let it dry completely before use,” adds Dr. Chow.

If you feel too sick to work out, you’re not being lazy. You’re being smart. Let your body do what it needs to heal, and the gym will still be there when you’re back to full strength.