A recent study from the University of Michigan has revealed that obese people who exercise regularly for long periods have healthier abdominal fat tissue that is more effective at storing fat compared to those who do not exercise. This finding could have important implications for how exercise contributes to better metabolic health, even in people who do not lose significant weight.
The study, led by Professor Jeffrey Horowitz, compared 32 obese people: 16 of them had exercised at least four times a week for more than two years, while the other 16 did not engage in regular physical activity. Despite having similar body mass, analyses of subcutaneous abdominal fat tissue – the fat found just under the skin – showed notable structural and biological differences between the two groups. The results are published in Nature Metabolism.
Long-term training is key to healthier fat tissue
The research team found that those who exercised regularly had fat tissue with more blood vessels, mitochondria (the cells’ “energy factories”) and proteins that support metabolic health. They also had lower levels of collagen type VI, a protein that, in excess, can interfere with fat cell metabolism. This type of collagen is associated with inflammation and metabolic dysfunction in people with obesity.
What’s most interesting is that exercise not only helps burn calories, but it also appears to remodel fatty tissue, making it more efficient at storing fat in a healthy way. “What this means is that if people experience weight gain, this excess fat will be stored more ‘healthily’ in this area under the skin, rather than in fatty tissue around their organs (visceral fat) or in a buildup of fat in the organs themselves, such as the liver or heart,” thereby reducing the risk of developing serious diseases such as non-alcoholic fatty liver disease, Horowitz explained.
The benefits of prolonged exercise go beyond reducing body fat. Participants who exercised also showed less inflammation in their fat tissue, which could protect them against various obesity-related health complications, such as cardiovascular and metabolic diseases. The researchers observed that the tissue’s ability to store lipids efficiently and its potential to generate new blood vessels were greater in those who exercised, which could improve overall metabolic health.
“What we see here is that regular exercise modifies fat tissue in a way that allows the body to more effectively handle excess fat,” Horowitz said. “This is crucial because as we age, almost all of us experience some weight gain. Having fat tissue that can store that fat in a healthier way is a key advantage in avoiding health complications.”
Implications for obesity treatment
This study provides a new perspective on the role of exercise in obesity. It is not just about losing weight, but about how the body manages fat. In an environment where obesity remains a public health concern, the findings underline the importance of regular physical activity, not only to reduce body fat, but also to improve the quality of fat tissue and its metabolic function.
One of the most serious problems associated with fat storage in inappropriate places is non-alcoholic fatty liver disease, a condition in which excess fat builds up in the liver, which can lead to cirrhosis or liver cancer. This study suggests that exercise may help prevent these complications by redirecting fat storage to less dangerous areas of the body.
What type of exercise is best?
Although this study did not look in depth at which type of exercise is most effective at improving fat tissue quality, Horowitz emphasizes the need for long-term studies exploring the intensity and frequency of exercise needed to achieve these changes. “Further research is crucial to understand how different types of exercise can modify fat tissue and improve metabolic health in people with obesity,” he concluded.
In future studies, the team also plans to examine how fat tissue in people who exercise regularly functions differently than in those who don’t, with the goal of identifying other health improvements that could result from these differences.
Ultimately, this study reaffirms the importance of exercise as a powerful tool to improve metabolic health, even in people who do not necessarily lose weight, by improving the body’s ability to manage fat more efficiently and safely.
Source: University of Michigan
