How Many Calories Does Muscle Really Burn? (and Why It’s Not About
Calories Anyway)
by
Mark Sisson
Mark’s Daily Apple
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The hallowed
halls of the Academy of Broscience contain untold tomes of knowledge,
wisdom, and recipes for "sick" pump stacks. Over the years, their
scholars have elucidated the arcane esoterica of muscle confusion,
thereby making it palatable for the layman. They discovered that
any gram of carbohydrate
eaten after dusk turns immediately to fat, and that curling in the
squat rack engages more muscle fibers than curling elsewhere. Their
field researchers are reportedly close to confirming the existence
of spot reduction. But perhaps their greatest contribution to modern
physical culture has been the establishment of the unassailable
fact that muscle burns fifty times more calories than fat, at fifty
calories per pound per day. (Even Dr. Oz says it, so it must be
true.) As they have so painstakingly shown, adding twenty pounds
of muscle increases your resting metabolic rate by 1000 calories.
With that kind of leeway, you could eat a delicious twenty egg-white
microwaved omelet with low-fat
cheese and a side of plain oats and never worry about body fat
accumulation!
This, of course,
is complete nonsense. Broscience is not even peer-reviewed and their
application for accreditation is still in administrative limbo.
No, but seriously:
the idea that muscle significantly boosts resting metabolic rate
is pretty much nonsense. Now, don't get me wrong. I like
muscle.
Love it, even. Nothing I like more than a bit of lean mass, but
I don't like how this notion of "muscle burning fat at rest" has
taken hold in the collective
psyche. It leads to lofty expectations that come thundering
down to shatter to pieces. It gets people on a single, obsessive
fitness track where all they want to do is lift, lift, and lift
(and eat, eat, eat) some more to the exclusion of other, perhaps
more enjoyable pursuits. And, it can even negatively impact one's
health or progress toward desired body composition, either via overtraining
the heavy lifting and undertraining
the other stuff, like sprints,
walks,
hikes,
and simple play.
Anyway, I came
across an article
several months ago detailing the author's discovery that muscles
don't actually burn that many more calories than body fat. He doesn't
cite any specific studies, but he does cite Claude Bouchard, an
obesity researcher from the Pennington Biomedical Research Center,
who revealed that a pound of muscle, at rest, burns about
six calories per day (and a pound of fat burns about two).
That's a far cry from the 50 calories per day figure "cited" by
others. This number isn't available in the abstract of some specific
study. It's drawn from extensive reading of the "biochemical and
metabolic literature". If you have literature to suggest otherwise
I'm all ears. For the purposes of this post, though, I'll take Claude
at his word.
So, straight
from the guy that studies this stuff for a living, muscle doesn't
burn a significant number of calories at rest. To illustrate the
point let me quote the author of the LA Times article:
The 20 pounds
of muscle I've gained through years of hard work equate to an
added 120 calories to my RMR. Not insignificant, but substantially
less than 1,000. However, I also engaged in a lot of aerobic activity
and dietary restriction to lose 50 pounds of fat, which means
I also lost 100 calories per day of RMR. So, post-physical transformation,
my net caloric burn is only 20 calories higher per day, earning
me one-third of an Oreo cookie. Bummer.
Or a single
macadamia nut as the case may be. But that doesn't mean having more
muscle isn't good for body composition and overall leanness, because
it definitely is. Let's look at some of the metabolic and other
benefits of having more muscle mass.
Recent
epidemiology (13,644 participating subjects) reveals that skeletal
muscle mass strongly correlates with improved insulin
sensitivity. With each 10% increase in skeletal muscle
index (a measure of how much muscle is on one's body), HOMA-IR (a
measure of insulin resistance) saw a relative reduction of 11%.
Folks with higher insulin sensitivity have better glucose control
(carbs don't destroy them) and lower rates of diabetes. Another
study looked at the relationship between sarcopenia,
or muscle wastage, and insulin resistance. There was a distinct
relationship between sarcopenia and insulin resistance, independent
of obesity, which can also exacerbate insulin resistance. So, based
on epidemiology, a lack of muscle is linked to increased insulin
resistance and poor glucose regulation. This should go without saying,
but sarcopenia was also linked to obesity.
Read
the rest of the article
August 12, 2011
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