As a general rule, when we get sick, we don’t feel up to performing our normal activities, particularly if it is an upper or lower respiratory illness caused by a virus. Often, we experience muscle aches and fatigue along with other symptoms such as nasal congestion, runny nose, sore throat, cough, wheezing, and fever. But if I want to exercise, is that safe? Are there times when I shouldn't exercise?
Exercise when experiencing a respiratory illness likely does not help or hurt the person’s recovery or speed of recovery.
Exercise should only be performed if the person’s symptoms are above the neck such as nasal congestion or sore throat, not chest congestion.
Exercise should not be performed if the person has a fever or signs of dehydration.
Exercise may make you sicker and lower your immune system response if you are suffering from a more serious illness such as the flu or COVID.
Regular exercise may help prevent the incidence of respiratory illnesses.
As we age, we have decreased lung capacity unless we have maintained regular physical activity. Taking a brief break from a regular exercise routine will not adversely affect the progress you have made over the years, especially if you are sick.
There are some of us who don’t have a choice. Our lifestyle and work demands that we be physically active, so slowing down is not much of an option unless we are suffering from severe symptoms. The vast majority of us lead busy lives. We don’t have time to be sick!
Fortunately, most respiratory illnesses last only a few days, so respiratory illnesses are not that disruptive. Everyone gets frustrated with feeling poorly and we all want to do whatever we can to not only feel better but feel better faster.
Will it hurt me if I exercise when I am sick?
The question often arises as to whether to continue an exercise routine during a respiratory illness. In most cases, exercise neither helps nor hurts if the illness is from the neck up. This means that it is a cold, sore throat (pharyngitis), or a sinus infection. It is never a good idea to exercise with lower respiratory symptoms such as chest congestion.
The overall answer about exercise also depends on the person, the severity of the symptoms, and whether the person has a fever. Worse symptoms mean a more difficult recovery and less of an ability to exercise or even perform everyday tasks. You should consider taking a break. That advice is particularly true if the person has a fever, chest congestion, or flu-like symptoms.
Flu or COVID may be more serious and indicate the person’s immune system is working overtime. Other considerations are whether the person has underlying chronic conditions such as heart or lung disease, diabetes, or gastrointestinal problems.
Does exercise help get rid of illness?
In the 1940s and 1950s, it was observed that people who played sports such as football became more likely to have more severe cases of polio. The studies at that time indicated that a serious illness, whether it is something like polio or today’s flu or COVID, may cause the body to react poorly.
Subsequent studies showed that intense exercise such as running a marathon while suffering from a respiratory infection may decrease the immune system response and work in an opposite manner, and make the person worse.
This is because our immune systems are already working overtime to fight the illness we have. Athletes who try to “sweat out” their illness may be taking unnecessary risks and find themselves sicker, particularly if they are suffering from more than the common cold.
Some athletes can develop chronic fatigue syndrome if they continue to exercise when experiencing flu or COVID. The science behind this phenomenon is still being studied, but the virus probably causes overall depression in the immune system. Many people, even non-athletes experienced this chronic fatigue, and it was termed long-COVID. Unfortunately, there is no known cure.
As a rule, listen to your body, and heed your body’s warnings if you need rest. Also, keep in mind that you may be contagious when you are sick, so being around others, especially in a closed environment like a gym, is not a good idea for everyone.
One of the most important things to do when you have a fever associated with a respiratory illness is to stay hydrated. Drink water or fluids containing sugars and electrolytes! Alcohol beverages can worsen dehydration, so avoid them.
The old adage “Starve a fever, feed a cold” is probably not accurate either. The reality is: you should feed both a fever and a cold. Improving your diet and hydration helps in all cases.
Does moderate exercise help prevent getting an upper respiratory illness?
Yes, clinical studies do suggest that moderate, regular exercise can be protective against upper respiratory illness and symptoms. It may be that the more intense and prolonged the exercise is, the more protective it is. Unfortunately, most of these studies rely on self-reporting of symptoms and there is a great variety in the reports of training status and exercise intensity.
The brief improvement many people who exercise while sick is usually short-lived, however, even if the symptoms are above the neck only. The person has improved their ability to breathe through their nose, but the congestion comes back quickly.
Since the person already has fatigue, regardless of the other symptoms, they may find they are more likely to tire more easily. In other words, they have less energy to begin with, and they have just used whatever energy they had to exercise. Now, they discover they cannot do their normal activities, such as work or play.
If the person has a fever, there is a detrimental effect because the body temperature is elevated. Dehydration becomes a real risk in these people, as they are already starting with a lower set point in their body fluid status.
The likelihood is that mild or moderate exercise does not alter the severity or duration of most upper respiratory illnesses. If you have experienced fevers with upper respiratory illness, it is recommended you wait a full week before getting back into regular exercise.
Start out moderately and then work your way back up to full exercise. Be aware of any muscle aches or weaknesses from the illness, as you will want those to subside before attempting to do anything strenuous.
Does age play a factor in recovering from respiratory illness?
This is an important point that many forget. Our lung capacity drops about 10% on average every decade over age 20. Dynamic exercise maintains our lung capacity and prevents this decline. This is why regular physical exercise is so important.
Underlying lung disease, heart issues, diabetes, and obesity can play a negative role in our ability to handle respiratory illnesses. Those people with these underlying health problems should have a heightened awareness of their need for rest, adequate hydration, and control of fevers when they are recovering from any respiratory illness.