6 minutes exercise a week is all you need to keep fit!

In news that will hearten the souls of all those couch potatoes out there, new research has shown that keeping fit and healthy may only require minutes of physical exercise each week.

Researchers at Canada's McMaster University say that in order to keep fit it may only be neccessary to do just six minutes of intense exercise a week and that could be just as effective as six hours of moderate activity.

The study showed short bursts of very intense exercise improved muscle capacity, and improved endurance, but experts warn it might be too much for people not already fit.

Current guidelines, advise people to take moderate aerobic exercise for 20-30 minutes three to five times a week.

The researchers compared 23 people, all reasonably fit and active, who were given different three-times-a-week training regimes.

One group cycled for two hours a day at a moderate pace, and a second cycled for 10 minutes a day in 60-second bursts, at a slightly harder pace.

A third group took part in sprint training - cycling at top speed for two minutes in 30 second bursts with four minutes rest between each sprint.

The volunteers all completed an 18.6 mile cycle ride at the start of the study, and repeated it after two weeks of training.

All three of the groups were found to have improved to the same extent.

Analysis showed the rate at which their muscles absorbed oxygen - a key measure of fitness - was the same, and levels of an enzyme called citrate synthase which helps the tissue to process oxygen, and helps to ward off diabetes, were also similar.

Lead researcher Professor Martin Gibala says the results showed that short bouts of very intense exercise improved muscle health and performance comparable to several weeks of traditional endurance training. He says sprint training may offer an option for individuals who cite "lack of time" as a major impediment to fitness and conditioning.

The study appears in the Journal of Applied Physiology.