Once-Weekly Interval Walking Matches Thrice-Weekly Exercise in Reducing Belly Fat

A clinical trial conducted by the University of Hong Kong’s School of Public Health found that performing brisk interval walking once per week yields similar reductions in body fat and improvements in cardiorespiratory fitness as exercising three times weekly in adults with central obesity.

The study, published in Nature Communications, involved 315 Chinese adults aged 18 and above with overweight and central obesity. Participants were randomly assigned to one of three groups: once-weekly interval training, thrice-weekly interval training, or a control group that received health education sessions.

Details of the Clinical Trial and Its Outcomes

Between September 2021 and September 2024, the two exercise groups completed 75 minutes of interval training weekly, either in a single session or split into three sessions. The control group attended biweekly 2.5-hour health education sessions over four months. Body fat mass was assessed using dual-energy X-ray absorptiometry at baseline, 16 weeks, and 32 weeks.

After 16 weeks, both interval training groups demonstrated comparable decreases in total fat mass, body fat percentage, and waist circumference. They also showed enhanced cardiorespiratory fitness relative to the control group.

Interval Training as a Time-Efficient Fat Loss Method

Interval training alternates brief periods of intense activity with recovery at lower intensity. It is regarded as a more time-efficient method for reducing visceral and overall body fat compared to steady moderate-intensity exercise. Traditional guidelines recommend thrice-weekly interval sessions, but this schedule may be impractical for individuals with busy lifestyles.

Previous research has indicated that “weekend warrior” exercise patterns, concentrating activity into one or two days, can still confer health benefits. However, evidence supporting once-weekly interval training specifically had been limited prior to this study.

Expert Commentary on the Findings

Professor Parco Siu Ming-fai, Head of the Division of Kinesiology at HKUMed’s School of Public Health, emphasized the importance of evaluating whether once-weekly interval training could match the benefits of more frequent sessions. He stated, “While thrice-weekly interval training remains a commonly recommended approach for the therapeutic management of excess adiposity, our findings show that once-weekly interval training offers similar benefits and represents a practical exercise strategy.”

He further noted that many adults with central obesity face time constraints due to work, study, and family commitments, which often hinder exercising multiple times per week. “Instead of relying solely on high-frequency exercise prescriptions, once-weekly interval training can be considered a feasible and effective alternative,” Professor Siu added.

Study Funding and Publication Information