Exercising is an efficient way to burn calories, but there’s no getting around the significant time investment required to get our reps in while juggling our personal and professional lives. So, a new study coming out of Hong Kong that supports brisk interval walking as a way of reducing our waist size comes as welcome news. And, better still, one long session is almost as good as three seperate stints, according to the latest science.
The new research, published in Nature Communications, provides encouraging news for those of us who are time-poor, or just too poor to afford a gym membership right now.
How was the study carried out?
Between 2021 and 2024, a group of 315 overweight adults were placed into three groups:
- Interval treadmill session: once per week
- Interval treadmill session: three times per week
- Control group
While the control group received support on the subject of health education, both walking groups completed a total of 75 minutes exercising. One group took on the full 75 minutes in a single session, while the other group split this into three sessions across the week.
Each of the working groups took on a warmup, including bodyweight squats and lunges, followed by a high-intensity interval (HIIT) program lasting 16 weeks. The walks were treadmill based for the purposes of the experiment, and the level of difficulty increased as the program continued, maintaining 85 to 95% of peak heart rate. Researchers chose the well-established 4x minute HIIT protocol, with 3 minutes of recovery time between each effort.
What were the results?
After 16-weeks, both walking groups lost a similar amount of weight, despite the different number of sessions. The three-times per week group lost 1.3 kilograms of fat on average, while the once per week gang were close behind at 700 grams. Both groups also lost around an inch from their waist size, but importantly, neither group were asked to restrict calories, meaning that exercise played the main role in the improved body composition. The fact that longer, single sessions can provide benefits close to a greater number of workouts provides further proof that a “Weekend Warrior” lifestyle is a sensible way to stay in shape when access to exercise is limited. While the experiment made use of the treadmill, there’s nothing to stop you getting outdoors and enjoying some fresh air.
“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,” said Professor Siu, who helped put the study together. “For many adults with central obesity who struggle to balance work, study, family and other commitments, time constraints are a primary barrier to exercising multiple days per week. Instead of relying solely on high‑frequency exercise prescriptions, once‑weekly interval training can be considered a feasible and effective alternative”