Sept. 10, 2024 – Overweight or obese people who exercise regularly over a long period of time may have healthier belly fat, compared to people who don’t exercise.
That’s according to the results of a new study published Tuesday in the journal Nature Metabolism. The researchers defined regular, long-term exercise as at least four times per week for at least 2 years.
“Our findings indicate that in addition to being a means to expend calories, exercising regularly for several months to years seems to modify your fat tissue in ways that allows you to store your body fat more healthfully if or when you do experience some weight gain – as nearly everyone does as we get older,” researcher Jeffrey Horowitz, PhD, a professor of movement science at the University of Michigan School of Kinesiology, said in a statement.
The study was small and included just 32 adults with obesity or overweight, half of whom were regular exercisers. The average body mass index among those in the study was around 30, which is the starting value for a person to have obesity. (Body mass index is a calculation of height and weight.) The people in each group were matched based on things like gender, weight, and body fat mass. They ranged in age from 25 to 37 years old.
The researchers took samples of the people’s belly fat tissue from just under the skin and found different structural and biological traits.
Exercisers’ tissue had a greater capacity to store fat just below the skin on the belly (the type you can pinch with your fingers), and that tissue functioned differently than the non-exercisers’ tissue. The exercise group’s tissue samples tended to have more blood vessels and beneficial proteins, and differences that meant a lower chance of inflammation and less of a type of collagen that can interfere with metabolism.
The findings are important because where fat is stored in the body can have different health impacts. Fat stored just under the skin, in what’s called subcutaneous adipose tissue, has less potential for negative health impacts, compared to when the body stores fat more deeply, such as around or even inside of organs. Such potentially toxic fat is called visceral fat and has been linked to heart disease, diabetes, and stroke.
“What it 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,” Horowitz said.
