The medical literature is replete with oodles of studies and articles supporting the benefits of exercise for everything under the sun. Some call it one of the strongest medicines available for the treatment of chronic illness. While we know how good it is, we don’t always know why it works for so many conditions. In this study, researchers provide another insight into the beneficial effects of exercise on immune health beyond the previously reported hormonal changes triggered by exercise.
Before delving into the details of the study, one might ask what exactly counts as exercise. For many of our chronically ill patients, especially those with chronic fatigue, this is a very practical question. Many cannot just throw on some tennis shoes and go for a 30-minute run. For some, even walking up a flight of stairs exhausts them. With these realities in mind, the answer to the original question of what counts as exercise therefore depends on the person. In general, we could define exercise as a physical activity which places a stressor of some sort (either cardiovascular or resistance stress are the two primary forms) which initiates an adaptation response in the person’s muscles and/or cardiovascular system. Depending on the individual’s physical capacity, this could vary from the simple act of walking to complex sports maneuvers involving multiple muscle groups. Regardless, it comes back to a physical activity causing a stress response in the person’s body.
With this general concept in mind, we return to the study in focus to understand what the researchers found. Put simply, the process of exercising mice on a treadmill altered the activities of immune cells called Tregs (“tee-regs”) in the muscles. Vast other research on these critical cells would tell us that these cells are responsible for controlling the extent of inflammation in various immune processes. Stimulating these cells logically would lead to the immune system improving its ability to prevent inflammation from causing as extensive damage to the body tissues as it might without Tregs. In these mice, this downregulation of inflammation did occur in response to the mice running on their little treadmills.
Now, just because exercise raises Treg numbers does not automatically mean that Tregs are the mechanism through which the anti-inflammatory effects of exercise take place. The researchers were too smart to assume that without further experimentation. By using mice that were genetically bred to not have Treg cells, they showed that in these Treg deficient mice, the inflammation continued unabated through the production of interferon, a chemical messenger of the immune system known to elevate inflammation. Clearly, the Treg cells were playing a role in the anti-inflammatory response.
One clinically and practically important fact needs mentioning here for those considering adding this exercise “drug” to their regimen. The researchers compared mice who only exercised once to those who were put on the treadmill for a regular workout. The one-timer mice did not show ongoing anti-inflammatory effects as was clearly seen in the mice who kept up their exercise routine. Therefore, don’t expect a 10-minute jog tomorrow to suddenly raise your Tregs and lower your inflammation. You will need to stick with the program for some duration of time before seeing the benefits.
I will add a final note. This study was in mice, so we can’t guarantee the exact same results in humans. However, the processes are likely similar in humans and mice given both are mammals and it is unlikely there is a major difference between the two. With that in mind, if you want the anti-inflammatory effects of exercise, plan on at least a few months of consistent exercise. To make this prolonged plan achievable, find something you like which pushes you physically rather than something you “have to do” just because it is exercise. The enjoyment benefits of doing something you like over and over will add to the benefits in terms of mood. While the study did not address how frequently you should exercise in order to expect anti-inflammatory benefits, I would say at least every other day given what we know from other studies about exercise. The benefits in other areas seem to wane after around 48 hours.
Living a healthier more abundant life includes incorporating what we call exercise into our weekly routines so that the potential benefits accumulate over time. This study just shed some light on how those benefits actually occur at a cellular level.
- Kent Langston, Yizhi Sun, Birgitta A. Ryback, Amber L. Mueller, Bruce M. Spiegelman, Christophe Benoist, Diane Mathis. Regulatory T cells shield muscle mitochondria from interferon-γ–mediated damage to promote the beneficial effects of exercise. Science Immunology, 2023; 8 (89) DOI: 10.1126/sciimmunol.adi5377
Thanks to Science Daily:
Harvard Medical School. “Some benefits of exercise stem from the immune system.” ScienceDaily. ScienceDaily, 3 November 2023. <www.sciencedaily.com/releases/2023/11/231103170639.htm>.
Sanctuary Functional Medicine, under the direction of Dr Eric Potter, IFMCP MD, provides functional medicine services to Nashville, Middle Tennessee and beyond. We frequently treat patients from Kentucky, Alabama, Mississippi, Georgia, Ohio, Indiana, and more... offering the hope of healthier more abundant lives to those with chronic illness.