HIIT shown to burn more fat in 20 minutes than an hour of walking

High‑Intensity Interval Training (HIIT) alternates short bursts of maximal effort with active recovery periods, raising heart rate to up to 90% of its maximum and triggering the post‑exercise oxygen consumption (EPOC) effect. A meta‑analysis of 150 studies found that a 20‑minute HIIT session can burn more fat than a full hour of walking, with elevated calorie expenditure lasting up to 24 hours after the workout.

Harvard researchers also highlighted HIIT as one of the most efficient modalities for reducing visceral fat, the metabolically active tissue surrounding internal organs. While HIIT can accelerate visceral fat loss, the study notes that lasting results require a combination of regular aerobic activity, strength training, balanced nutrition, and adequate sleep. Benefits reported include improved cardiovascular conditioning, increased insulin sensitivity, and faster overall fitness gains compared with longer, lower‑intensity exercise.

The findings suggest that short, intense interval sessions offer a time‑efficient alternative for individuals seeking to improve body composition and metabolic health.