Millions of people already choose running as their preferred form of exercise, owed to a vast array of mental and physical health benefits, but new research has added more reasons to lace up your sneakers. In addition to burning fat, lowering stress, and improving stamina, running has now been linked with stronger bones and an improved immune system.
In the new study, carried out by the Sean Morrison Laboratory at UT Southwestern, a team of scientists identified that forces generated by walking or running are transmitted to bone forming cells. Researchers found that a signal is passed along the arteriolar blood vessels and is directed to the marrow, inside the bones. This facilitates new bone to form and thicken. Additionally, the bone-forming cells release growth factors that results in more B and T cells, boosting your ability to fight off infection. It appears that bone-forming cells sense the pressure caused by body movements (also known as mechanical forces), and this leads to the positive effects.
“As we age, the environment in our bone marrow changes and the cells responsible for maintaining skeletal bone mass and immune function become depleted. We know very little about how this environment changes or why these cells decrease with age,” says Sean Morrison, Ph.D., the director of CRI and a Howard Hughes Medical Institute Investigator. “Past research has shown exercise can improve bone strength and immune function, and our study discovered a new mechanism by which this occurs.”
The study, first published on Nature.com, used mice to demonstrate that when pressure-sensing cells were deactivated, their bones became thinner and had a reduced ability to clear bacterial infections. The scenario was then reversed by placing running wheels into the cages so that the mice could exercise. This was the first clue that mechanical stimulation could regulate a niche in the bone marrow.
“We think we’ve found an important mechanism by which exercise promotes immunity and strengthens bones, on top of other mechanisms previously identified by others,” says Morrison.