Many people who regularly exercise will tell you they feel healthier and more energetic. Most doctors tout that regular exercise is good for your heart, lungs, bones, muscles and overall health. But does regular exercise keep you from getting sick from the common cold?
I’ve been a fitness fanatic for most of my life, but like most people, I experience periods when exercise becomes less-routine. Interestingly, I am more likely to catch a cold and have it linger for several days when I’m not on my exercise schedule. It seems as if my immune system takes time off when exercising gets disrupted. I rarely catch a cold when I’m in my routine of daily aerobic exercise (15-20 min/day). Could this be psychological?
Physiological, not Psychological
Research has reported a beneficial impact on our immune system when we engage in moderate, regular, aerobic exercise. Our immune system is a network of cells that communicates with itself as well as other cells and tissues, by releasing different types of substances. Common cold and flu viruses are helpless outside of cells. So these tiny microscopic particles invade specific human cells and take over certain cell functions in order to make more virus particles and continue to survive.
Certain circulating white blood cells, called lymphocytes, are capable of making defense antibodies against viruses. These antibodies may attach to human cells that are infected with a virus, and facilitate a subsequent attack by acting as a recognizable signal to other human white blood cells. Other white blood cells may directly attack infected cells by recognizing abnormal features of the infected cells. Regular exercise may increase the number of lymphocytes and other important immune cells important for first-line defense against viruses and other germs.
A University of Illinois study (Urbana-Champaign) on 144 seniors compared the response to flu vaccination in a subgroup that exercised aerobically versus those who only did flexibility and balance training. Interestingly, the seniors who engaged in aerobic activity had higher (30-100%) protective antibodies compared to the other group. There was no difference in reported respiratory illness, but the aerobic exercise group had reduced severity of illness and less sleep disturbance.
A study by David C. Nieman ( Director of Human Performance Laboratory, North Carolina Research Campus) reported the frequency and severety of upper respiratory tract infections (URIs) in a thousand adults age, age 18 to 85 (60% female). They were followed over a 12 week period during the winter and fall seasons. Those who exercised five or more times weekly had 43% fewer URIs compared to the group who exercised one or less times weekly. Severity of URIs was also reduced by 30-40% in the high exercise group compared to the low one.
Can too much or too rigorous exercise be harmful?
A couple of studies I reviewed showed increased infections along with decreased wellness in athelites who exercised inetensely. Apparently, the immune system can be stressed by intense or prolonged exercise. For example, some marathon runners experience greater susceptibility to colds and other URIs.
Take Home Points:
- Regular moderate aerobic exercise may help prevent colds and perhaps reduce severity of URIs. This includes running, jogging, brisk walks, biking, using the elliptical, or similar equipment. - Regular exercise continues to be an important item on the recipe for good overall health. - Intense workouts may have the opposite affect and increase your chances of getting sick from a cold or flu. - A nutritionally balanced diet, adequate sleep and regular checkups may help to complete your wellness profile.
Message for adults: Consult your family doctor before embarking on a new aerobic exercise schedule if you have been relatively inactive, or have other medical problems.
Have you noticed that get fewer colds when you’re exercising regularly?
I’d like to know.