Sprinting also known as high intensity exercise can burn 200 calories, much more than jogging or walking, states research.
Colorado State University researchers compared the energy expenditure of a group of men on two different days: one spent watching TV, the other doing high-intensity exercise followed by long periods of recovery.
To determine how many calories a typical sprint-interval training workout might burn, reserach team leader Kyle Sevits and his colleagues at Colorado recruited healthy male volunteers, aged between 25 and 31 years, the Daily Mail reports.
Over three days, the men ate a diet calculated to give their bodies exactly the right amount of calories, so they weren't over or under-eating. One group then spent a day being sedentary, watching TV, while the other group exercised.
This involved pedalling as fast as possible on an exercise bike set at a high resistance (i.e. effort rate) for five 30-second periods. Each exercise was separated by four-minute periods of recovery, in which they pedalled slowly with very little resistance.
During the intense, 30-second bouts, researchers coached the volunteers over an intercom system, encouraging them to give 100 percent effort.
On the sprint-interval workout day, the men burned an average of an extra 200 calories, despite spending just 2.5 minutes engaged in hard exercise.
"Research shows that many people start an exercise programme but just can't keep it up," said Sevits. "The biggest factor people quote is that they don't have the time to fit in exercise," he added.