We can't claim we're too busy for exercise anymore after Scottish researchers found just two and a half minutes of high intensity exercise could be as effective as a 90-minute run.
Research shows short, sharp bursts of exercise followed by rest are far better at preventing heart disease than longer, less intense sessions.
Dr Stuart Gray from Aberdeen University asked nine men aged 18 to 35 to do 30 minutes of exercise –– either high intensity sprinting then resting, cycling or walking.
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After four rounds of sprinting for 30 seconds, followed by a four-minute rest, the men had 33 percent reduction in blood fat content –– the equivalent of a 90-minute run. Those who walked briskly for half an hour had an 11 percent reduction compared with not doing exercise at all.
To measure blood fat, the volunteers returned to the laboratory the following day and were fed a fatty breakfast and lunch before the researchers measured the fat in their blood.
Fat that lingers in the blood after eating can lead to clogging of the arteries and contribute to heart disease.
Dr Gray told the British Science Festival that short bursts of exercise could help the liver process more fat from the blood before storing it or burning it off.
"Although moderate intensity, longer sessions of exercise can help protect the body against cardiovascular disease, the findings of our study showed that higher-intensity, shorter intervals of exercise might be a more effective method to improve health and reduce the time commitment to exercise," Dr Gray said.
Exercise physiologist Dr Adam Fraser told ninemsn this is the first study that he's aware of that measured fat in blood after interval training.
"For a number of years now, we have known that interval training is far more effective for helping people lose weight than standard training," he said.
"This new study is looking at a different parameter –– fats in your blood. It's a new, novel finding because I don't think I've ever heard anyone measure that effect. It's a small group of people but given all the other stuff that shows interval training is really great, it's quite powerful."
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Dr Fraser said doing short bursts of high intensity exercise is not only effective, but it's easier to fit into a busy schedule.
"Interval training certainly helps people lose more weight, gets them fitter faster and makes exercising more interesting compared to slogging it out for 45 minutes," he said.
"If you could do something six times a week, that would be awesome but even if you did it three times a week you're still going to get great results."