Don’t overdo it, but light exercise can help with minor illness.
The winter flu season is still in full force, according to the US Centers for Disease Control and Prevention, causing many sufferers to halt their exercise regimen. But not every illness requires you to set down your gym bag. While moderate to severe ailments require a certain amount of rest and recovery, mild illnesses may improve with movement.
“To be totally inactive and bedridden has a negative impact on your immune system, energy levels and recovery ability,” said Walter Gjergja, cofounder of the fitness app Zing Coach who is based in Lugano, Switzerland. “It’s usually beneficial to have some activity, although of the appropriate quantity and quality.”
The standard medical advice is that when your symptoms are above the neck (e.g., a tension headache, stuffy or runny nose, or minor sore throat), it’s fine to engage in mild to moderate exercise.
But if your symptoms strike below the neck — think ailments such as chest congestion or an upset stomach — back off. Never exercise if you have a fever, which is a sign your body is fighting an infection or viral disease.
The type of exercise you should do while battling a mild illness depends upon factors such as your typical activity level, the weather (if exercising outdoors), and your age and overall health.
“If you have a mild to moderate illness, you can continue to exercise, but you should do less than you normally do,” said family physician Dr. Bruce Barrett, a professor and vice chair for research in the department of family medicine and community health at the University of Wisconsin-Madison. “If you normally run 10 miles per week, maybe run 5 if you have a mild cold. Just tamp it down.”
Going for a walk is one of the gentlest and healthiest forms of exercise, Gjergja said. But if the temperature is below about 50 degrees Fahrenheit (10 degrees Celsius), it’s better to exercise inside.
“When the air is cold, it can irritate the lungs and bronchial area,” Gjergja said. “This could trigger coughing or emphasize any inflammation that was abating, and you could get sicker.”
Pay attention to the air quality, too, Barrett said. If it’s poor, move indoors to protect your lungs.
Slow, easy movements are best
Gentle stretching is another great option for an active recovery, especially for those who do not exercise regularly, Gjergja said. Consider doing some shoulder rolls, ankle circles, leg raises or seated spinal twists. Practices such as yoga, qigong and tai chi are helpful, too.
“These activities are very gentle in terms of energy expenditure,” Gjergja said, “but stimulate our circulation and benefit our body by moving all of our joints.”
The key is not to overdo it, something avid exercisers struggle with when sickness strikes.
“Those are the ones I worry more about,” Gjergja said. “They immediately want to return to their training, which brings the risk of slowing their recovery and having the illness recur. It’s just not worth the rewards, which are minimal.”
In addition, heavy exercise done while experiencing a respiratory viral illness can lead to chronic fatigue and even exacerbate myocarditis, or inflammation of the heart muscle, according to a 2021 study published in the journal BMJ Open Sport & Exercise Medicine.
Move more to ward off future illness
Once you are fully recovered, take a look at your exercise habits. If you haven’t been working out regularly, consider making it a habit to ward off future ailments.
“People who exercise regularly have fewer and shorter illnesses,” Barrett said.
He should know. Barrett led one study, published in 2012 in the journal Annals of Family Medicine, evaluating the possible preventive effects of meditation or exercise on acute respiratory illness. The results? Both practices significantly reduced the incidence, duration and severity of colds and influenza in the populations studied.
“For those who don’t regularly exercise, if they start exercising two or three or four hours per week, it can reduce their chance of getting sick,” Barrett said. “Covid and flu shots work, but exercise prevents all respiratory infections.”
The link between exercise and illness prevention and recovery may be one reason qigong is increasingly studied today. A traditional Chinese practice, qigong combines gentle movements with breathing exercises and meditation. A growing number of studies show some causality between qigong and the immune system’s response and recovery from illness, Gjergja said.
A June 2020 meta-analysis published in the journal Medicines indicated qigong and tai chi positively affect your body’s immune system and its response to inflammation. Qigong also was found helpful in treating arthritis, depression and anxiety, and hypertension in a May 2022 study published in the Biomedical Journal of Scientific & Technical Research.
The bottom line? Get moving.
“Some form of exercise will help improve your life and condition,” Gjergia said. “I’ve worked with people with mild to severe health issues, including heart conditions and strokes. For all of them, some type of exercise was helpful.”