Diabetes Forecast

Overdoing Exercise can Weaken Immune System

By Matt McMillen , , ,

Photo Credit: Zinkevych/BigStock

What to Know

Exercise benefits your heart and helps you better manage your blood glucose levels. Some research suggests that, in certain cases, exercise may briefly lower your white blood cell count. That would temporarily make it harder for your immune system to fight infections such as cold and flu viruses. A new review of scientific studies, however, offers a simple workaround that may help reduce your risk of getting sick.

The Study

Australian researchers reviewed 129 studies of people without diabetes published between 1985 and 2016 that focused on exercise and susceptibility to illness. Some studies looked at whether different levels of exercise intensity affected the immune system differently. Other studies explored the relationship between repeated bouts of exercise on the same day and the risk of illness. The aim of the review was to find ways in which people can offset an exercise-weakened immune system.

The Results

Exercise, the researchers point out, stresses the lungs, skin, and other organs. The immune system interprets this stress as a threat, sending disease-fighting white blood cells to respond. That leaves the body temporarily less able to fight infections. The longer and more intense the workout, the longer it takes for the immune system to resume its full vigilance against illness. But, the researchers reported, a carbohydrate snack during exercise can help maintain the immune system, while a snack right after can help restore it to normal strength.


Focus on moderate exercise in order to better protect yourself against infections. On days that you do push yourself harder, eat a carbohydrate-rich snack during or right afterward to help stabilize your blood glucose. That will reduce your body’s stress response and encourage your white blood cells to return to their posts as disease defenders. Further research must be done to confirm this post-workout effect. In general, more study is needed to better determine the relationship between illness, the immune system, and exercise.

Recovery of the immune system after exercise.” Jonathan M. Peake, Oliver Neubauer, Neil P. Walsh, and Richard J. Simpson. Journal of Applied Physiology, May 1, 2017; 122(5):1077-1087.

The information on this screen does not take the place of care from your doctor or other health care provider. If you have general questions about diabetes or diabetes-related research, e-mail askada@diabetes.org or call 1-800-DIABETES (800-342-2382).



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