To lose body-fat, sprinting for just an hour per week is better than jogging for seven hours, says a new study.

An hour per week or about 20 minutes per day for three days a week would be enough to lose body fat, especially in men.

“Sprints are a very time efficient form of exercise,” says Associate Professor Steve Boutcher, who led the University of New South Wales Medicine research.

The study lasted for 12 weeks, during which the participating men lost 2 kilograms, or about four and a half pound of body fat and put on 1.2 kilograms or a little over 2 and a half pounds of muscles in their legs and trunks. Also, they lost 17 percent of visceral fat.

Previous research has shown that high intensity exercises like sprinting are effective in improving health of overweight men with a sedentary lifestyle.

“The sprint program, LifeSprints, reduced visceral fat with seven times less exercise time and has a much greater impact on cardiovascular and metabolic health than reductions of subcutaneous fat stores in the legs and arms," said Steve Boutcher.

Experts recommend 30 minutes per day of moderate exercise for adults. Regular physical activity strengthens muscles, helps prevent type 2 diabetes and even keeps people from getting depressed. However, endurance exercises done over long durations, like marathons, may put people at high risk of various heart problems.

“Other studies using aerobic exercise, such as continuous jogging, have found that the amount of exercise needed to produce a similar decrease in visceral fat was around seven hours per week for 14 weeks,” Professor Boutcher says.

Sprinting helps in gaining muscle mass, researchers say.

“Participation in regular aerobic exercise typically results in little or no gain in muscle mass, whereas moderately hard resistance exercise over months may increase muscle mass. The amount of LifeSprints exercise, however, needed to significantly increase muscle mass appears to be much less,” Professor Boutcher said.

The study was published in the Journal of Obesity.