Exercising doesn’t just reduce fat — it helps the body store fat in a healthier way, according to a new study.
Body fat is necessary because it provides insulation and stores and releases energy. Blood vessels and nerve cells in body fat also play a crucial role in the endocrine system by sending hormone signals to other organs. Researchers at the University of Michigan set out to learn about the impact of long-term exercise – not in terms of how it burns calories but in terms of how it affects the makeup of fat itself.
The study, published Tuesday in Nature Metabolism, included one group of 16 adults with obesity who exercised at least four times a week over two years, and another group of 16 adults with obesity who did not regularly exercise. The two groups otherwise matched in terms of body fat mass, weight and sex. The research found that samples of belly fat tissue of the exercisers had characteristics that enabled them to store more fat under the skin, rather than around or in organs. The exercisers’ belly fat had fewer cells that cause inflammation and less of a negative type of collagen, as well as more blood vessels, mitochondria and beneficial proteins.
What this means “… is that if or when people experience weight gain, this excess fat will be stored more ‘healthfully’ in this area under the skin, rather than in the fat tissue around their organs (visceral fat) or an accumulation of fat in organs themselves, like the liver or heart,” the study’s principal investigator Jeffrey Horowitz said in a release.
For instance, about 10% to 20% of Americans have nonalcoholic fatty liver disease – which is on the rise in the United States due to obesity rates and other issues – which occurs when fat builds in the liver. About 2% to 5% of people in the United States have nonalcoholic steatohepatitis, a type of fatty liver disease that causes inflammation, liver damage and other complications, according to the Johns Hopkins University School of Medicine.
Further research into whether the type and intensity of exercise impacts how the body modifies fat tissues is needed, the researchers concluded. They also noted that increasing the capacity to store fat was not the same as gaining fat. Consuming more calories than you burn in a day causes increased fat or weight gain.