Exercise burns the fat found within bone marrow, with benefits for bone health, according to a study published in the Journal of Bone and Mineral Research.
Researchers at the University of North Carolina at Chapel Hill (UNC) said that this process improves bone quality and the amount of bone in a matter of weeks. What’s more, greater bone health benefits are seen in obese individuals — who often have worse bone quality.
“One of the main clinical implications of this research is that exercise is not just good, but amazing for bone health,” said lead author Dr Maya Styner, a physician and assistant professor of endocrinology and metabolism at UNC. “In just a very short period of time, we saw that running was building bone significantly in mice.”
Although findings from mice are not directly translatable to humans, the kind of stem cells that produce bone and fat in mice are the same kind that produce bone and fat in humans, the university noted.
As well as its implications for obesity and bone health, Dr Styner said the research also could help illuminate some of the factors behind bone degradation associated with conditions like diabetes, arthritis, anorexia, and the use of steroid medications.
It also offers insights on how marrow fat forms and the impact it has on bone health. Previous studies have suggested that a higher amount of marrow fat increases the risk of fractures and other problems.
“There’s been intense interest in marrow fat because it’s highly associated with states of low bone density, but scientists still haven’t understood its physiologic purpose,” Dr Styner explained. “We know that exercise has a profound effect on fat elsewhere in the body, and we wanted to use exercise as a tool to understand the fat in the marrow.”
The study suggests that it’s possible to use exercise to reverse some of the effects of osteoporosis and fractures on bones.
“I see a lot of patients with poor bone health, and I always talk to them about what a dramatic effect exercise can have on bones, regardless of what the cause of their bone condition is,” Dr Styner added. “With obesity, it seems that you get even more bone formation from exercise.”