Now researchers have uncovered one more benefit: Exercise helps make our metabolisms more efficient. A new study that looked at how our cells work during exercise found that exercising actually converts the type of fat cells we have, changing them from metabolically inactive “white fat” to “brown fat,” which burns more calories.
The new research is some of the strongest evidence yet that the benefits of working out (in terms of your waistline) aren’t limited to the number of calories burned ― and why.
And it helps explain why regular exercise is so key for all those other health outcomes, explained study author Li-Jun Yang, a professor of hematopathology in the University of Florida College of Medicine’s department of pathology, immunology and laboratory medicine.
“We all know regular exercise is good for our health,” Yang told The Huffington Post. “But our work provides [additional] direct biological explanations or mechanisms why people who regularly exercise can maintain lean bodies and stronger bone structure.” Both of these help prevent obesity and metabolic diseases including diabetes, heart disease and stroke.
It’s all thanks to a hormone released during exercise
Researchers believe all of these exercise super powers have to do with a hormone called irisin, which the body produces during exercise.
In a lab experiment the researchers exposed fat cells to irisin, which boosted activity of another protein in the fat cells that actually converted white fat cells into brown fat cells.
Brown fat helps the body burn calories rather than storing them. And brown fat has previously been shown to improve other aspects of our metabolism, too, including insulin sensitivity and glucose tolerance, which are known to help ward off obesity, heart disease and diabetes.
The fat browning effect from exercise has previously been shown to happen in mice, but this is the first time researchers have observed it happening in human cells.
Irisin’s benefits go beyond getting rid of fat
The researchers also found that when irisin was mixed with stem cells in the fat tissue (the young fat cells that have not yet become full-fledged adult fat cells), instead of actually growing into adult fat cells, the stem cells became another type of cell that help strengthen our bones.
The researchers found 20 to 60 percent fewer fat cells in the tissue that had been soaked with irisin compared with a control group of tissue that had not received the hormone.
It’s important to point out that this research was done in human cells in a lab, not human cells in actual people. The next step is to replicate the experiment in living people to confirm that the hormone actually does work this way in real life, Yang explained to The New York Times.
At this point, the reasons to exercise are pretty convincing, Yang told HuffPost.
But this new study may add a little extra motivation that making it part of your regular routine has benefits that are way more than skin deep.
Sarah DiGiulio is The Huffington Post’s sleep reporter. You can contact her at firstname.lastname@example.org.