By Paul Gustafson, PhD, RKT, RPG Kinesiotherapy, LLC, Edgefield, SC
In recent weeks there has been an increased interest in methods to protect oneself from infection. Reducing one’s exposure to infection has recently been a priority in our minds and in media reports. Another topic receiving somewhat less but important attention is that of maintaining and enhancing one’s immune response to infection. Our immune system uses cells of various types as warriors to resist or combat infections and chronic disease. There is evidence that a regular exercise program can enhance the performance of our immune system (5).
It has been known for some time that cardiorespiratory exercise, also known as aerobic exercise, can enhance the performance of our immune system (5) by increasing the numbers of some of the cellular warriors to one degree or another. Activities using large muscle groups, performing large limb movements, performed rhythmically for an extended period of time can qualify as cardiorespiratory exercise.
More recently, resistance training (strength training) has also been shown to enhance the performance of the immune system in women with breast cancer (3). Ultra-high intensity resistance training is not necessary to increase the numbers of some of the cellular warriors of the immune system. In fact there is some debate regarding evidence that exercise of ultra-high intensity may temporarily suppress the immune system in highly trained, elite athletes (4). Regardless of the outcome of that debate, there is significant agreement in the scientific community that regular bouts of moderate to vigorous intensity exercise will assist the immune system to function properly and will help to lower the risk of respiratory illness/infection and some cancers (4). Exercise routines found successful in sedentary or moderately active individuals may not translate to highly trained, elite athletes (6).
Before beginning an exercise program one’s physician should be consulted. The American College of Sports Medicine (ACSM) recommends 150-300 minutes per week of moderate-intensity aerobic physical activity and 2 sessions per week of strength training. There are indoor and outdoor activities that may be used to meet the ACSM guidelines (1). In order to maintain immune health one should begin with an easily tolerated intensity and gradually increase the intensity over a period of weeks. Adding variety of activity will assist in decreasing the monotony of the exercise routine (6). The ACSM offers a list of specific activities one can use to meet their guidelines. There are also frequently asked questions with reference to COVID-19 addressed on their website as well (1).
Exercise is not the only variable that can affect the immune system. Factors such as potential exposure to disease causing organisms, health status, lifestyle behaviors, sleep and recovery, nutrition and psychosocial issues also play a role (4, 6). In 2007 The ACSM along with the American Medical Association (AMA) co-launched the Exercise is Medicine (EIM) initiative. The purpose of EIM is to make physical activity assessment and promotion a standard in clinical care (2).
Exercise engagement is something we can immediately control. You are encouraged to follow the lead of the ACSM and AMA and ask your healthcare provider for recommendations regarding exercise in your health maintenance plan.
3. Hagstrom, AD et al. (2016). The effect of resistance training on markers of immune function and inflammation in previously sedentary women recovering from breast cancer: a randomized controlled trial. Breast Cancer Research and Treatment, 155: 471-82.
4. Simpson, RJ et al. (2020). Can exercise affect immune function to increase susceptibility to infection? Exercise Immunology Review, 26:8-22.
5. Walsh, NP et al. (2011). Position Statement Part one: Immune function and exercise. Exercise Immunology Review, 17: 6-63. 6. Walsh, NP et al. (2011). Position Statement Part two: Maintaining Immune Health. Exercise Immunology Review, 17: 64-103.