Once-a-Week Workout Cuts Belly Fat, Study Finds

A new study led by Professor Parco Siu Ming-fai from the University of Hong Kong’s School of Public Health (HKUMed) has found that a single weekly session of brisk interval walking may significantly reduce abdominal fat in overweight adults. Published in Nature Communications, the research enrolled 315 Chinese adults with central obesity and suggests that once-a-week interval training could be as effective as three sessions per week—a finding that may reshape exercise recommendations for those struggling to fit frequent workouts into busy schedules.

The Hidden Dangers of Belly Fat

Obesity is a chronic health condition involving an unhealthy buildup of body fat, and fat accumulating around the abdomen is associated with cardiovascular disease, metabolic disorders, and a higher risk of premature death. Além disso, the visceral fat that wraps around internal organs is particularly harmful, pumping out inflammatory substances that disrupt normal bodily functions. Portanto, reducing this dangerous fat is a priority for public health, yet typical solutions often demand more time and effort than many people can sustain. Consequentemente, these risks underscore the urgent need for accessible and effective interventions that fit into varied lifestyles.

Exercise Barriers for Many Adults

Exercise plays an important role in managing obesity and offers a wide range of health benefits, but many people, particularly those living with obesity, struggle to maintain regular physical activity over time. No entanto, most exercise recommendations call for interval training three days each week, but that schedule may be difficult for people with demanding jobs, family responsibilities, limited time, or restricted access to exercise facilities. Além disso, even the most motivated individuals can find it challenging to carve out multiple exercise sessions each week. Portanto, this has led researchers to explore time-efficient alternatives that could deliver meaningful results with a lower time commitment.

Interval Training: A Time-Efficient Option

Interval training alternates between more vigorous periods of exercise and lower-intensity periods of active recovery, and research has shown it can be a time-efficient way to reduce overall body fat and visceral fat compared with continuous moderate-intensity exercise. Por exemplo, the approach typically involves short bursts of brisk walking or cycling interspersed with slower-paced movement, allowing people to achieve significant fitness gains in shorter workouts. But the typical recommendation of three weekly sessions still poses a hurdle for many individuals, prompting the question of whether even less frequent training could work.

Can Once a Week Be Enough?

Professor Parco Siu Ming-fai, Professor and Head of Division of Kinesiology at the School of Public Health, HKUMed, said it was important to determine whether once weekly interval training could match the results of a traditional three-session schedule and provide a more accessible alternative. Portanto, he and his team set out to test this hypothesis in a real-world setting, focusing on adults with central obesity who stand to benefit most from a practical fat-loss strategy. Ou seja, the goal was clear: to see if a once-a-week belly fat workout could stand on par with the more demanding standard regimen. Assim sendo, to answer this, the team designed a rigorous trial that tracked body composition changes over several months.

Details of the Hong Kong Trial

From September 2021 to September 2024, the HKUMed team carried out a randomized trial in Hong Kong involving 315 Chinese adults aged 18 or older, all of whom were overweight and had central obesity. Em seguida, participants were assigned to one of three groups: one group completed interval training once each week, another completed interval training three times each week, and the third served as a control group. Ademais, the control group took part in a 2.5-hour health education session every two weeks for four months, while both exercise groups completed a total of 75 minutes of interval training each week, with one group performing the full amount in a single session and the other dividing it across three sessions. Dessa forma, this design allowed the researchers to isolate the effect of frequency from total training volume.

How Results Were Measured

Researchers measured body fat using dual-energy X-ray absorptiometry at baseline (before the program began), after 16 weeks (post-intervention), and at 32 weeks (four-month post-intervention follow-up). Além disso, the scanning technology provided precise data on overall fat mass and, crucially, changes in abdominal fat. Portanto, after analyzing the data, the team found that both exercise groups experienced reductions in abdominal fat compared to the control group, with no significant difference between once- and three-times-per-week schedules. Ademais, Professor Siu added: “Instead of relying solely on high-frequency exercise prescriptions, once-weekly interval training can be considered a feasible and effective alternative.” Em resumo, the results indicate that a single dedicated session can be just as powerful as multiple shorter ones for trimming belly fat.

A Practical Path Forward

The findings support once weekly brisk interval walking as a practical therapeutic option for adults with central obesity, especially those who struggle to fit several workouts into their schedules. Por exemplo, this once-a-week belly fat workout could be integrated into a weekend routine or a lunch break, dramatically lowering the barrier to regular exercise. No entanto, as with any new exercise program, individuals should consult a healthcare professional to ensure the activity is appropriate for their health status. Sobretudo, the study also reinforces the value of interval training, suggesting that quality, not just quantity, matters in the battle against belly fat.

The study was published in Nature Communications and led by Professor Parco Siu Ming-fai, with co-first authors Dr. Leung Chit-kay and Mr. Joshua Bernal, all from the School of Public Health, HKUMed. The research was supported by the General Research Fund of the Research Grants Council, the University Grants Committee of Hong Kong, China, and the Seed Fund for Basic Research, HKU.

Source

• www.sciencedaily.com
• Materials (www.hku.hk)
• The University of Hong Kong (www.hku.hk)
• 10.1038/s41467-025-68149-7 (dx.doi.org)
• SCITECHDAILY.com (scitechdaily.com)
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