No more excuses! Just 2.5 minutes of intense exercise a day can burn 200 calories
15:00 GMT, 12 October 2012
If your usual excuse for not exercising is a lack of time, then it's bad news.
Exercising intensely for as little as 2.5 minutes a day can burn around 200 calories, say researchers from Colorado State University.
They 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.
The cheat's guide to exercise: Pedalling as fast as you can for five, 30-second intervals could be enough to burn 200 calories
High-intensity exercise is where maximum effort is put in to work the body as hard as possible.
The theory is that a quick burst of sprinting is more productive than jogging or walking for a prolonged period.
To determine how many calories a
typical sprint interval training workout might burn, lead researcher Kyle Sevits and his
colleagues recruited five healthy male volunteers, all between the ages
of 25 and 31.
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.
High intensity exercise such as sprinting can be fit into a smaller time frame
After that, they spent one day being sedentary, watching TV, and another exercising.
This involved pedaling as fast as possible on an exercise bike set at a high resistance (i.e. effort rate) for five 30-second periods.
Each was separated by four-minute periods of recovery, in which they pedalled slowly with very little resistance.
During the intense, 30-second bouts, the researchers coached the volunteers over an intercom system, encouraging them to give 100 per cent 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 program but just can't keep it up,' said Mr Sevits.
'The biggest factor people quote is that they don't have the time to fit in exercise.
'We hope if exercise can be fit into a smaller period of time,then they may give exercise a go and stick with it.
'Burning an extra 200 calories from these exercises a couple of times a week can help keep away that pound or two that many of us gain each year.'
Official guidelines suggest we do 150 minutes of moderate exercise or 75 minutes of vigorous exercise per week.
Yet research suggests less than a quarter of people in the UK actually manage it.