Here's the fastest way to burn calories

• Published date: 11 October 2021
• Author: WALLA!
• Publication title: Jerusalem Post, The: Web Edition Articles (Israel)

Almost anyone who has a passing interest in exercise has probably heard of high-intensity interval training (HIIT), a workout of short, intense and repetitive bursts of exercise called intervals, with rest periods of a few seconds in between.

However, the ideal length of each interval (each burst of exercise), remains unclear. What is certain is that such intense training shouldn't be too exhausting, and any interval should be as strenuous and tolerable as possible.

For Dr. Edward Coyle, an expert in kinesiology (science of body movement) who heads the Human Performance Lab at the University of Texas at Austin, that means a period of about four seconds.

He and his colleagues came to this number after examining professional athletes. During physiological tests in Dr. Coyle's lab, the athletes created speed and power while pedaling on special stationary bikes equipped with a heavy wheel which had no resistance. Within two seconds of pedaling these unique bikes, the researchers saw that the athletes reached an overall level of aerobic effort which they maintained for a short time while continuously repeating the motion, with a few seconds of rest between exercises.

Since we aren't all professional athletes, Dr. Coyle's estimate for the general public was double the time i.e. four seconds. But can four seconds really provide enough exercise? To try to find out, he and his colleagues conducted a series of additional experiments.

During the first study published last year, they asked college students to complete five repetitions of four-second intervals on the specially designed bike, each hour over an eight-hour...