30-second bursts of intense exercise amounting to only three minutes a week could deliver the health benefits of hours of lengthy, conventional regimes, researchers say.
This may revolutionise our ability to stick to New Year fitness resolutions, which only one in five of us manage to keep for more than a few weeks, the Daily Mail reported.
The study found that the main reason we break resolutions is that our plans are over-ambitious - we set the bar too high in a hopelessly optimistic burst of post-Christmas enthusiasm.
But this new exercise regime lowers that bar significantly. Scientists at the universities of Nottingham, Birmingham and Bath say the secret is to commit yourself to three short bursts of highly intense exercise for 30 seconds each, with short rest periods between, in less than five minutes.
They claim early results are ground-breaking and may lead to conventional medical textbooks on exercise being torn up. Instead of sweating for hours, scientists say we should hurl ourselves around on an exercise bike or rowing machine - or even just run rapidly up and down the stairs at home.
After half a minute of wild exertion, we can collapse red-faced for 60 seconds, then do it all again. Three bouts like that means your exercise requirement for that session is sorted.
The ongoing study is led by leading exercise expert Jamie Timmons, a professor of systems biology. The team call their system High Intensity Impact Training (HIIT).
So far, their tests on hundreds of unfit middle-aged volunteers in Britain and Canada over the past eight years have shown those three minutes of exercise a week deliver the same significant health improvements as can be achieved through hours in the gym or on the running track.
But scientists do not yet entirely understand why the short-burst exercise regime so profoundly boosts volunteers' stamina and the fitness of their lungs, heart and blood vessels.
As for weight loss, the results from conventional long hours of exercise regimes often prove disappointing.
Typically, exercisers get themselves into trouble by eating more than they do normally because strenuous gym sessions leave them ravenous.
Brief, high-intensity exercise does not stimulate appetite as much, because it demands far less energy expenditure, so participants in the trial don't suffer the same cravings.
What's more, it appears to do something even more beneficial, according to Professor Timmons.
The regime should also raise people's metabolic rates after they stop exercising, as it builds muscle - and this tissue makes metabolisms run faster. In turn, this stimulates the breakdown of fat and burns calories.
The study has been published in the Journal of Clinical Psychology.