Long-Term Exercisers Have Healthier Belly Fat, Even If Obese, Study Finds

For individuals with obesity, the advantages of regular exercise go beyond just weight loss. A recent study indicates that consistent exercise leads to changes in fat tissue that allow for safer storage of any gained or regained weight, compared to those who do not engage in physical activity.

Those who exercise regularly tend to store excess fat beneath the skin rather than around vital organs, reducing the risk of developing cardiovascular diseases, diabetes, and liver disease.

Principal investigator Jeffrey Horowitz stated, “We can improve our metabolic health through exercise by promoting healthier fat tissue.”

Weight gain, a common occurrence due to reduced physical activity, overeating, and aging, results in fat accumulation. Horowitz emphasized the importance of reframing how people perceive fat: “Fat tissue is not the cause of weight gain; it is simply where excess energy and weight are stored.”

“Having a safe place to store fat, such as under the skin in the abdomen or lower body, is preferable to storing it in excessive amounts in vital organs like the liver, heart, or pancreas, which can lead to various health challenges,” added Horowitz, who also serves as a professor of movement science at the University of Michigan School of Kinesiology.

Regular Exercise Promotes Healthier Belly Fat

The study, published on September 10 in Nature Metabolism, revealed that regular exercise leads to fat tissue with distinct structural and biological characteristics that aid in more effective fat storage.

Researchers compared two groups of obese adults: one group consisted of 16 individuals who exercised at least four times a week for over two years, while the other group included 16 non-exercisers. Both groups were matched for body weight, fat levels, and sex, with fat tissue samples collected from the abdominal region.

According to Horowitz, the fat tissue of exercisers exhibited:

• Enhanced blood vessel presence for improved oxygen and nutrient delivery
• Reduced rigidity, allowing fat cells to expand more effectively
• Less inflammation and inflammatory markers

The fat tissue of regular exercisers was also softer and more flexible, making it more likely to be stored under the skin rather than around vital organs.

“During periods of overeating and weight gain, having fat tissue that can expand effectively and has good blood flow is beneficial,” Horowitz explained.

Furthermore, the researchers found that fat tissue developed from cells of exercisers stored fat more effectively compared to those from non-exercisers.

“Overall, these findings indicate that fat tissue in individuals who exercise regularly may be metabolically healthier than in those who do not,” said Cheehoon Ahn, the study’s first author.

Safer Weight Gain

The improved quality of fat tissue in regular exercisers suggests that even if individuals with obesity gain weight, their fat is more likely to be stored in healthier subcutaneous areas rather than around vital organs, reducing the risk of obesity-related complications.

One increasingly recognized condition in the U.S. is nonalcoholic fatty liver disease, which predominantly affects overweight or obese individuals by causing unhealthy fat accumulation in the liver.

“Ultimately, leading a physically active lifestyle can enhance health by promoting healthier fat tissue,” Horowitz concluded.

Reasons of Benefit Unknown

While the study highlights the benefits of exercise, the exact mechanisms through which exercise induces these changes remain unknown. Hormonal shifts and molecular signaling between tissues likely play a key role in promoting healthier fat tissue.

Horowitz mentioned ongoing research to investigate the effects of exercise on health outcomes, particularly when weight is regained after a weight loss program. The research will compare the impact of weight loss achieved through diet alone versus diet combined with exercise, as well as examine differences in fat tissue between exercisers and non-exercisers.

Further studies will aim to determine the specific types or intensities of exercise that yield more significant results, providing deeper insights into how exercise influences overall health and fat metabolism.