It's not quite that simple, as you'll realise if you saw the BBC Horizon programme on Tuesday night
Doing short bursts of high intensity training (HIT) - a cycle sprint, running upstairs or sprinting full pelt - for one minute in 20-second bursts, three times a week, can give you many of the health benefits previously believed to have come from exercising for an hour and a half on a weekly basis.
That was one of the messages in the BBC Horizon: The Truth About Exercise programme screened on Tuesday night February 28, 2012.
The show, presented by medically trained Dr Michael Mosley, also advised that people who are active throughout the day have a higher metabolism and burn more calories.
Hardly a radical conclusion, but still useful to bear in mind if you have a job which is largely sedentary.
Dr Mosley also underwent tests that proved exercise does get easier, at least as far as your brain is concerned: it learns to cope better with discomfort and therefore allows you to work out at a higher, harder level.
Experts showed that pushing yourself to the absolute maximum capacity for a total of one minute (in three 20-second bursts), three times a week, breaks down the glycogen in muscles more effectively than exercising at a medium or gentle pace.
That's because you are using more of your muscle capacity than lower level exercise performed for longer. As a result, you are smashing glucose out of your muscles, increasing your insulin sensitivity and you are therefore less likely to suffer from Type 2 diabetes.
So what can regular exercisers take away from Dr Mosley's experiences?
Read more about the Horizon programme on the BBC website.
Like us on facebook
Follow us on twitter
Other Hearst Magazines UK sites