While John Cloud erred in several ways in his Time magazine
article titled Why
Exercise Won’t Make You Thin, he's correct on the fat loss issue. Many
people including the Surgeon General have lambasted Mr. Cloud for his candor
and scientifically sound information on getting svelte.
What he was saying is that exercise does not affect fat loss
much if at all. And research on the subject of exercise and fat loss supports
his statement time and time again. Even the American College
of Sports Medicine agrees that exercise does little to affect it as we’ll learn
shortly.
The knee-jerk reactions that bombarded the internet lambasting
Cloud for the article which include Jake Steinfeld (the Jake of Body by Jake Fame) only serve to keep people
fat and injured. They assume that Cloud
is saying that exercise is not good for us or that it provides no benefit. That
is not what John Cloud was saying. And he does, in fact, make mention of the many
benefits of exercise. In fact he even says at the end of the article “You
should exercise to improve your health…” Again, the title of the article is
"Why Exercise Won't Make You Thin." And it won't. It never has and
that is a fact of science. Good for John for having the guts to reveal this
information and help us all get closer to the truth and, perhaps, save us from
an orthopedic injury.
Jake Steinfield, who may I say I respect and admire, had
this to say on his Huffington
Post blog:
“Cloud states that the American College
of Sports Medicine and the American Heart Association's guidelines regarding
weight loss and exercise are unrealistic, especially for those with jobs or
those looking for jobs. The guidelines encourage exercise for 60 to 90 minutes
on most days of the week. What he fails to mention is that they also say that
"research shows that moderate-intensity physical activity can be accumulated
throughout the day in 10-minute bouts, which can be just as effective as
exercising for 30 minutes straight. This can be useful when trying to fit
physical activity into a busy schedule."
What Jake neglects to mention is that, unfortunately for those
who seek to lose weight via exercise, the ACSM admits exercise doesn’t work.
From the AHA/ ACSM paper titled: Physical
Activity and Public Health. Updated Recommendation for Adults From the American
College of Sports Medicine and the American Heart Association (page 7):
“It is reasonable to assume that persons with relatively
high daily energy expenditures would be less likely to gain weight over time,
compared with those who have low energy expenditures. So far, data to support
this hypothesis are not particularly compelling.”
Also from Jake’s Huff Post blog (he is quoting Dr. Robert
Sallis, past president of the American College of Sports
Medicine):
"If exercise were a
pharmaceutical it would be the most potent drug ever invented. Exercise has
been clearly proven to prevent and treat chronic diseases and lower mortality
rates. From a scientific perspective, any attempt to discredit the value of
exercise is just laughable and potentially very harmful to the public. As a
physician who works hard to get patients more active, I find it very
irresponsible for Time magazine to run a story that so misrepresents
the facts."
Well, Dr. Sallis isn’t quite
correct. All of the studies done on exercise that are used as iron clad proof
that exercise prevents and treats chronic disease and lowers mortality rates
are epidemiological / observational studies. These types of studies are not controlled
research studies. They can only suggest an association - they do not prove
cause and effect. Just because people who exercise regulary live longer and are
generally healthier than those who don’t doesn’t mean that the exercise caused
these benefits.
But why? Why does exercise have little to no effect on fat
loss? There are many reasons including increased appetite and being more
sedentary after the workout. An interesting example of this was watching my
daughters ride their bikes around Mackinac Island last week while we were on vacation and after the 8 mile ride all they wanted
to do was sit in bed and read.
But the most important issue is the understanding of the
language of fat loss. What tells the body to release fat from the fat cells?
Fat loss is not a numbers game. In other words, a calorie is
not always just a calorie. Fat loss is a hormonal game. Fat is not released
from the fat cells because you burn calories doing exercise. No one loses fat
without altering their diet and sticking to that alteration. And the specific
alteration is a reduction in carbohydrates, not necessarily calories, which in
turn reduces insulin secretion, which in turn allows the lipids to be released
form the fat cell. That's the biochemistry. We don't get to vote on it. There
are other issues, but this is far and away the most critical.
And why do so many experts and the ACSM assume exercise will
work even though time and time again research fails to support the assumption.
So too do the failures of millions of Americans who try to shed the pounds by
sweating to the oldies.
A thorough read of Gary Taubes' book Good
Calories Bad Calories explains this in great detail. According to Gary:
"Obesity is a disorder of excess fat accumulation. So
the question everyone should be asking and always should have been asking is
what factors regulate fat accumulation? As it turns out we've known that since
the 1960s and it is not controversial. You can find it in endocrinology and biochemistry
textbooks, just not in obesity textbooks. Fat accumulation is fundamentally
determined by the hormone insulin and our insulin levels go up and down with
the quantity and quality of carbohydrates we consume. The more carbs we eat,
the more refined they are and the sweeter they are (the more fructose in them,
in other words), the more insulin we will ultimately secrete. The higher our
insulin levels, the more fat we accumulate."
Exercise cannot and does not solve the problem of fat
release from the fat cell. The real key to the fat cell is not exercise. It is
the control of hormonal tone and the most important hormone to control is insulin.
As the late Carl Sagan said: "Science as a candle in
the dark."