The connection between exercise and inflammation has captivated the imagination of researchers ever since an early 20th-century study showed a spike of white cells in the blood of Boston marathon runners following the race.
Now, a new Harvard Medical School study published in Science Immunology may offer a molecular explanation behind this century-old observation.
The study, in mice, suggests that the beneficial effects of exercise may be driven, at least partly, by the immune system. It shows that muscle inflammation caused by exertion mobilizes inflammation-countering T cells, or Tregs, which enhance the muscles’ ability to use energy as fuel and improve overall exercise endurance.
Long known for their role in countering the aberrant inflammation linked to autoimmune diseases, Tregs now also emerge as key players in the body’s immune responses during exercise, the research team said.
“The immune system, and the T cell arm in particular, has a broad impact on tissue health that goes beyond protection against pathogens and controlling cancer. Our study demonstrates that the immune system exerts powerful effects inside the muscle during exercise,” said study senior investigator Diane Mathis, Morton Grove-Rasmussen Professor of Immunology in the Blavatnik Institute at HMS.
Mice are not people, and the findings remain to be replicated in further studies, the researchers cautioned.