Exercise guidelines often demand several sessions a week - a barrier many people simply cannot clear. A four-month randomized trial involving 315 adults with central obesity suggests the math may be more forgiving than assumed: 75 minutes of brisk interval walking done in a single weekly session cut body fat and improved heart fitness just as effectively as the same total time split across three sessions.
Researchers at the University of Hong Kong (HKUMed) assigned participants to once-weekly or thrice-weekly high-intensity interval walking, volume-matched at 75 minutes per week, against a control group. After 16 weeks, both exercise groups showed significant reductions in body fat and gains in cardiorespiratory fitness, with no meaningful advantage to spreading the sessions out. For inactive adults with excess abdominal fat, the authors say, a single protected 75 minutes may be a practical route into exercise.
The finding is not a license to skip exercise entirely - both groups trained at brisk interval intensity, and the study lasted only four months. But it challenges the assumption that frequency is essential to benefit, and it offers a realistic on-ramp for the many adults for whom "three times a week" is the reason they never start.
