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http://www.msnbc.msn.com/id/35581793/ns/health-fitness/
LONDON - People who complain they have no time to exercise may soon need another excuse.
Some
experts say intense exercise sessions could help people squeeze an
entire week's workout into less than an hour. Intense exercise
regimens, or 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 handle it. If true, that
could revolutionize how officials advise people to exercise — and save
millions of people hours in the gym every week. It is also a smarter
way to exercise, experts say.
"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.
Still,
most studies have been done in young, healthy adults, and experts
advise people to consult a doctor before starting any fitness program.
For
Adamson Nicholls, a 36-year-old Londoner and martial arts enthusiast,
interval training is a way to boost his endurance so he can outlast
sparring opponents. "It's a shortcut to explosive fitness," he said,
adding the training results in snappier and heavier punches.
Using
interval training, Nicholls got into top shape last year in about six
weeks, using weekly 45-minute sessions. He estimates the same level
would have taken about three months via regular training.
Experts
say that's because intense bursts of activity are precisely what the
body needs to build stronger muscles. Traditional workouts lasting an
hour or more simply don't push the body enough.
"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 fiber 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."
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