Fri, Feb-23-07, 11:01
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Plan: Muscle Centric
Stats: 238/153/160
BF:
Progress: 109%
Location: UK
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Just stopping by to post this snippet from Tom Venuto's e-newsletter that I've just received:
Quote:
Can You Really Lose More By Exercising Less?
This article on the latest "fitness revolution" in high intensity
interval cardio training is brought to you with the compliments
and permission of my friend and colleauge from the UK, Christian Finn
of the excellent Facts About Fitness website (www.FinnsFitnessFacts.com).
Christian's commentary was prompted by the recent news reports of
the Australian study (actually not published yet), which claimed
that 20 minutes of interval training using 8 second intervals was
superior to other forms of cardio and burns three times as much fat.
I was going to write about this myself, but I think Christian did a
brilliant job explaining the truth behind this claim and about HIIT
cardio in general and he was kind enough to let me republish his article
Train hard and expect success,
Tom Venuto
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Can You Really Lose More By Exercising Less?
By Christian Finn
www.FinnsFitnessFacts.com
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Just the other day, I came across a story about another "revolution
in weight loss," with scientists claiming to have devised a workout
that burns three times more fat than regular workouts lasting twice
as long.
According to the story, the researchers found their specific brand
of interval training triggers a metabolic response that allows more
fat to be burned under the skin and within the muscles.
Can you really lose weight three times faster with only half
the exercise?
Here, as Kent Brockman would put it, is my two cents.
First, let's take a closer look at what happened in the study.
Researchers at the University of New South Wales and the Garvan
Institute studied a group of overweight women, putting them through
a 20 minute cycling regime in which they sprinted on a stationary
bike for 8 seconds followed by 12 seconds of cycling lightly [1].
The women performed the workout three times a week for 15 weeks.
"They lost three times more weight than other women who exercised
at a continuous, regular pace for 40 minutes," says University of
New South Wales Associate and study co-author Professor Steve Boutcher.
The scientists believe the regime would also be applicable to swimming,
walking, running and rowing.
Other types of interval training using longer work and rest periods,
says Professor Boutcher, are not as effective for overweight people.
As far as I can tell, the work-rest ratio (8-second sprint, 12-second
recovery) is based on a previous study by the same researchers showing t
hat short work and rest ratios burn more calories than longer (24-second
sprint, 36-second recovery) intervals.
Boutcher thinks the current government recommendations for exercise
are largely ineffectual. "Walking for 60 minutes, seven times a week
does not result in much fat loss, usually 1.15 kilograms over 15 weeks,"
he says. "For a lot of overweight people this is going to be a revolution."
So, is this a revolution in weight loss?
Maybe. if you've had your head in the sand for the last 10 years.
Using interval training to lose fat is certainly not a revolutionary
idea. It forms the core of the cardiovascular workouts featured in
the Fight Fat and Win (FFW) programs. And there are plenty of other
people who have been writing about it - and using it - for a number
of years.
However, even though interval training is both a highly effective
and time-efficient way to train, saying that it'll help you lose
weight "three times faster" than regular cardio does (in my opinion,
anyway) paint a rather overly optimistic picture about what to expect.
I'll explain why in a moment.
Yes, I know that interval training is often said to be "nine times"
more effective than steady-state aerobic exercise. However, if you've
actually read the study on which this claim is based (Interval Training
and Fat Loss: The Untold Story), you'll know that neither group in the
study lost a significant amount of weight. The aerobic exercise group
lost one pound, while the interval-training group lost an average of
just 100 grams. And that was after 15-20 weeks of regular exercise.
With all the fuss about interval training and fat loss, you'd think
there are dozens of studies to show that it consistently leads to
greater fat loss than steady-state cardio. But there aren't.
It's true that interval training is a great way to increase calorie
expenditure in the hours after exercise. It's also been shown to boost
the activity of various fat-burning enzymes. However, most studies of
interval-style workouts have looked at changes in performance and
fitness, rather than weight loss.
Studies to track changes in body composition are few and far between,
which is one of the reasons this Australian study caught my eye.
However, when I looked at the research in detail (and the paper has
yet to reach the pages of a peer-reviewed journal, so I only had
access to a short summary of the study), the results weren't quite
as exciting as they first appeared.
At the end of the 15-week study, the interval-training group had lost,
on average, 2.5 kilograms (5.5 pounds) of fat. The steady-state group
actually gained 0.5 kilograms (1.1 pounds).
So, the actual amount of fat lost in the interval training group wasn't
all that great - 5.5 pounds over 15 weeks, which works out at just 0.37
pounds of fat loss per week. This figure doesn't really grab your attention
like "three times greater weight loss."
In fact, I can't actually figure out how the researchers arrived at a
figure of "three times greater weight loss," as the interval-training
group lost weight while the steady-state group gained it.
What about diet? How did that affect the results?
Although the women's calorie intake was monitored using a food diary,
self-reporting is a notoriously inaccurate way to estimate calorie
intake. Some studies show that people underestimate their calorie
intake by up to 50% [2]. In other words, someone who says they are
eating 1000 calories per day may really be eating 2000 calories.
So, changes in calorie intake might have been primarily responsible
for any weight loss. Or they might have had nothing to do with it.
We don't really know for sure.
And we still don't know how well interval training compares to more
intense steady-state cardio. This study used only moderate-intensity
cardio (60% VO2max). To trigger a substantial post-exercise calorie
burn, you need to work at around 75% of VO2max, or 85% of your maximum
heart rate. It's possible that steady-state cardio performed at or above
this threshold would produce very similar results to interval training.
With all that said, I still think that interval training is a great
way to lose fat. It's something I use myself and recommend to others.
In fact, the interval training used in this Australian study is very
similar to the level III workout in the Fight Fat And Win (FFW) program,
which involves a 25-minute workout sandwiched between 5 minutes of
warming up and 5 minutes of cooling down.
However, interval training alone is not a magic bullet, and I think
most people would be disappointed losing only 5.5 pounds of fat after
15 weeks of exercise. A program that combines resistance exercise, good
nutrition AND interval training is one that will deliver the best results.
C Finn, UK
References
1. Trapp, E.G. & Boutcher, S.H. Fat loss following 15 weeks of high
intensity, intermittent cycle ergometer training. University of New
South Wales, Sydney, Australia
2. Lichtman, S.W., Pisarska, K., Berman, E.R., Pestone, M., Dowling, H.,
Offenbacher, E., Weisel, H., Heshka, S., Matthews, D.E., & Heymsfield, S.B.
(1992). Discrepancy between self-reported and actual caloric intake and
exercise in obese subjects. New England Journal of Medicine, 327, 1893-1898
About The Author
Christian Finn holds a masters degree in exercise science, is a certified
personal trainer and a regular contributor to Men's Health, Men's Fitness
and other popular fitness magazines.
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The revolution in weight loss story that they are talking about was actually posted here on the forum for those who are interested: http://forum.lowcarber.org/showthread.php?t=321619 |
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Interesting!!
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