Battling another cough or cold? Feeling tired all the time? Taking a daily walk or following a simple exercise routine a few times a week may help you feel better.
Exercise helps decrease your chances of developing heart disease and keeps your bones healthy and strong.
We don't know exactly if or how exercise increases your immunity to certain illnesses, but there are several theories (none of these theories have been proven). Some of them are:
Physical activity may help flush bacteria out of the lungs and airways. This may reduce your chance of getting a cold, flu, or other airborne illness.
Exercise causes changes in antibodies and white blood cells (the body's immune system cells that fight disease). These antibodies or white blood cells circulate more rapidly, so they could detect illnesses earlier than they might have before. However, no one knows whether these changes help prevent infections.
The brief rise in body temperature during and right after exercise may prevent bacteria from growing. This temperature rise may help the body fight infection more effectively. (This is similar to what happens when you have a fever.)
Exercise slows down the release of stress-related hormones. Some stress increases the chance of illness. Lower stress hormones may protect against illness.
Although exercise is good for you, be careful not to overdo it. People who already exercise regularly should not exercise more intensely just to increase their immunity. Heavy, long-term exercise (such as marathon running and intense gym training) could actually decrease the amount of white blood cells circulating through the body and increase stress-related hormones.
Studies have shown that people who go from a sedentary ("couch potato") lifestyle to a moderately energetic lifestyle benefit most from starting (and sticking to) an exercise program. A moderate program can consist of:
Bicycling with your children a few times a week
Taking daily 20 - 30 minute walks
Going to the gym every other day
Playing golf regularly
Exercise can help you feel better about yourself, just by making you feel healthier and more energetic. So go ahead, take that aerobics class or go for that walk. You'll feel better and healthier for it.
There is no strong evidence to prove that taking immune supplements along with exercising lowers the chance of illness or infections.
Johnson R, Knopp W. Nonorthopaedic conditions. In: DeLee JC, Drez D Jr, Miller MD, eds. DeLee and Drez's Orthopaedic Sports Medicine. 3rd ed. Philadelphia, PA: Elsevier Saunders; 2009:chap 3.
Walsh NP, Gleeson M, Shephard RJ, et al. Position statement. Part one: Immune function and exercise. Exerc Immunol Rev. 2011;17:6-63.
Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.