A week's exercise could be squeezed into one hour.

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http://www.telegraph.co.uk/health/healthnews/7320590/A-weeks-exercise-could-be-s\

queezed-into-one-hour-say-experts.html

 

Published: 7:30AM GMT 26 Feb 2010

 

Interval training was originally developed for Olympic athletes and thought to

be too strenuous for normal people.

 

But in recent years, studies in older people and those with health problems

suggest many more people might be able to benefit from them saving millions of

hours in the gym every week.

 

" High-intensity interval training is twice as effective as normal exercise, "

said Jan Helgerud, an exercise expert at the Norwegian University of Science and

Technology. " This is like finding a new pill that works twice as well ... we

should immediately throw out the old way of exercising. "

 

Intense interval training means working very hard for a few minutes, with rest

periods in between sets. Experts have mostly tested people running or biking,

but other sports like rowing or swimming should also work.

 

Helgerud recommends people try four sessions lasting four minutes each, with

three minutes of recovery time in between. Unless you're an elite athlete, it

shouldn't be an all-out effort.

 

" You should be a little out of breath, but you shouldn't have the obvious

feeling of exhaustion, " Helgerud said.

 

In Britain and the U.S., officials recommend that people get about two and a

half hours each week of moderate exercise.

 

Helgerud says that time could be slashed dramatically if people did interval

training instead. He said officials have been too afraid of recommending intense

training, fearing it might be too much for some people.

 

" I'm much more afraid of people not exercising at all, " he said. " Inactivity is

what's killing us. "

 

When compared to people on a normal exercise routine, like jogging, research has

shown those doing interval training can double their endurance, improve their

oxygen use and strength by more than 10 percent, and their speed by at least 5

percent. Even studies in the elderly and in heart patients found they had better

oxygen use and fitness after doing interval training.

 

Howevr, most studies have been done in young, healthy adults, and experts advise

people to consult a doctor before starting any fitness program.

 

Intense bursts of activity help the body to build stronger muscles.

 

" A lot of the (benefits) from exercise are due to a stress response, " said

Stephen Bailey, a sports sciences expert at the University of Exeter. " If you

disturb your muscles, there's an imbalance created and your body will start

signaling pathways that result in adjustments. "

 

Bailey said intense bursts of exercise help the body to convert one type of

muscle fibre into another type that uses oxygen more efficiently and is capable

of exercising a lot longer. Even though interval training only takes a few

minutes, its effects last for hours.

 

" You've exercised at such a high intensity that you're going to create a massive

disturbance in your muscles, " Bailey said. " That creates a higher metabolism for

several hours afterward, which the body will bring down by burning fat and

carbohydrates. "

 

Helgerud and others predicted that as further studies confirm interval training

is safe for wider populations, authorities will include it in their exercise

guidelines.

 

" This is definitely the way forward to save time on your exercise, " Nicholls

said. " The results are worth it. "