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Researched
and Composed by
Jacob Wilson, BSc. (Hons), MSc. CSCS
Address correspondence to:
jwilson@abcbodybuilding.com
Layman’s Journal of
HYPERPLASIA Research 1(4):
Published August 31, 2006
Introduction
I
recently attended one of the world’s largest conferences in exercise science.
The American College of Sports Medicine Annual Meeting, which this year was held
in beautiful Denver Colorado.
Conference rooms as far as the eye could see were filled with some of the
world’s greatest minds, either in the audience or presenting data which had not
even been published yet. The science of muscle growth was discussed from a
molecular, genetic, and holistic perspective, among literally every topic known
in the exercise science world. For a hard working scientists such as myself, a
conference such as this is comparable to placing a kid in a candy store, or
better yet for my soon to be 4 year old nephew…Toys R us! You could imagine my
disposition, too many conferences to attend and such limited time! But because
I am president of a bodybuilding site, I tried to choose seminars related to
muscular hypertrophy. However, with the number of seminars occurring I found
myself in a dilemma. On a number of occasions two to three speakers were
addressing issues on muscular growth at the same time! Fortunately I was able
to get recordings of hundreds of the seminars for my own personal listening
pleasure (what a relief).
What was interesting was that one of the most fascinating symposiums I attended
was not related to muscle growth at all. In fact, it was not even about
exercise! Instead it was on a subject known as Non Exercise Induced
Activity Thermogenesis, and was headed up by Dr. Levine from the Mayo clinic and
his colleagues. During the seminar one of the most intriguing things occurred.
First all the speakers in the symposium stood for the duration of the talk,
meaning even while one individual was speaking the others ignored their
designated seats. Then, by the end of the talk the majority of the large crowd
of mostly exercise physiologists were also standing while listening to the
seminar, with their seats conspicuously left empty. What strange forces caused
these individuals to leave their seats you ask? Take a seat…or better yet stand
if you like and I’ll explain.
How
Humans Expend Energy
When we
look at human beings we see all sorts of shapes and sizes. Some individuals are
lean, and some carry too much body fat. For lean individuals, body fat is
stored enough to last maybe 2-3 months tops, where as obese individuals can
carry enough energy to last over a year in length (Levine, 2004). The variables
which determine whether an individual is lean or obese are almost too many to
count. For example, a bodybuilder can take in more energy than he or she
consumes and still stay relatively lean simply because the excess nutrients are
directed towards muscle tissue rather than purely to fat. For sedentary
individual however most excess energy is stored as fat. Of course even
bodybuilders are constantly dealing with minimizing fat gain, if this weren’t
the case we wouldn’t have to go on cuts so often. The variable of where
nutrients go falls under the umbrella of nutrient partitioning. This is
affected by both our diet and exercise. The second variable is definitely
energy balance.
In general if energy consumed exceeds energy expended then we gain weight.
Because not all energy is partitioned to muscle stores this energy is also
stored as fat. Conversely when cutting the goal is to create a caloric deficit,
where calories expended exceed calories consumed. The following article is
concerned with energy expended.
Energy expended can be divided into basal metabolic rate, the thermic effect of
food, and activity thermogenesis (Levine et al., 2006).
Basal metabolic rate is the energy you expel while at rest, and averages out to
be about 60 % of total energy expelled in a given day. Studies show that the
difference between individuals basal metabolic rates (e.g. what makes one person
expend more calories than another) is explained mainly by differences in lean
body mass (Levin, 2004). This is one of the reasons why when you are dieting
your best bet is to do everything you can to maintain the lean body mass you
gained while bulking, if not gain additional lean body mass. The formula is
simple à
when calories go down, anticatabolic agents should go up! This includes being
extremely cautious about obtaining proper leucine intake (see this months
article on leucine practical applications), HMB, fish oil pills, glutamine, high
protein intakes, proper pre bed meals, and the consumption of some source of
protein in the middle of the night.
The thermic effect of food accounts for 10-15 percent of calories expended in a
given day. Essentially eating, digesting, processing and assimilating food
requires energy. What is interesting is to study how to manipulate this
variable, but that is a topic for another article. I can briefly say however
that proteins have a greater thermic effect than other macronutrients, followed
by carbohydrates, and then fats, which have very little thermic effect. Just by
upping the proportion of protein in your diet you can metabolize more fat.
The final category was activity thermogenesis. According to Levine and
colleagues this can be further divided into activity associated with exercise
and the calories it expends and non exercise induced activity or NEAT. NEAT
concerns activities which are physical but fall outside of exercise such as
pacing, fiddling, typing, talking, standing, tying your shoes, and other
occupational activities performed at work or school Studies indicate that NEAT
may explain the majority of the difference between individuals in terms of their
energy expended in a given day. In fact, it ranges from 15-50 % of total
calories expended in a given day depending on whether an individual is sedentary
or active (Levin, 2004, Levin et al., 2006). For individuals who do not
exercise this is critical. You will note however that exercise induced energy
expenditure is manipulated typically through increased cardiovascular output.
Given
the immense importance of NEAT to metabolizing fat, the following paper will
analyze what components effectively lower or increase NEAT and how you can
manipulate these components in your own program.
Environmental factors
There are a number of environmental factors affecting NEAT. One of the major
factors is the development of time saving and leisure devises such as washer
machines, dishwashers and elevators which have lowered NEAT. In one study
Lanningham and colleagues (2003) analyzed the effects of activities such as
washing dishes, walking to work, and climbing the stairs vs. using a dishwasher,
driving, and taking the elevator and found that people who did not use labor
saving devises expended an extra 120 calories per day (figure 1), which adds up
to nearly 12 pounds of fat per year. Remember that changes in body composition
are typically best viewed in chronic programs, as day to day variations are
small.
Figure
1. Example comparison of elevator riding compared to stair climbing.
In
another study Levine and colleagues correlated or looked for relationships
between sales of labor saving devises and obesity and found that as labor saving
devises increased so did obesity, while in contrast food intake did not
correlate!
A
further factor effecting NEAT is occupation, with drastic differences in
comparison of those whose jobs are labor intensive compared to sedentary desk
jobs.
The
seasons also effect NEAT for obvious reasons such as rain and cold and their
effects on lowering opportunities for outside activities. Studies indicate that
NEAT is double in the summer compared to winter months (Levine, 2004).
While
environment plays an important role, a great deal of evidence suggests that NEAT
is very much biologically dependent.
At the
conference Dr. Levine and colleagues presented some of the most powerful
evidence that NEAT is greatly related to genetics by comparing Obese individuals
to lean individuals. Here’s a summary of some of the data they presented.
Lean
individuals have higher levels of NEAT than obese individuals.
Explanations
It may
simply be that obese individuals have a harder time moving around then leaner
individuals, and so avoid NEAT activities.
To examine this possibility the Levine lab placed naturally obese rats on a diet
until they had the same body fatness of their leaner rat counterparts. Still
NEAT did not increase, suggesting a genetic component.
One of
the suggestions is that we have a NEAT center in our brain which controls
spontaneous activity(Levine, 2004). This center integrates incoming signals so
as to increase or decrease NEAT depending on the situation at hand. One of the
hormones identified to increase NEAT upon administration is orexin. Orexin
administration increases NEAT, and as evidence would have it, when Orexins are
administered to lean individuals they increase activity substantially more than
obese individuals, suggesting that obese individuals may be resistant to the
effects of Orexins.
Energy
Availability As the primary regulator of NEAT
NEAT is
directly correlated with energy intake. As energy intake increases, NEAT levels
increase. Evidence even suggests that it is the proficiency of this process
which determines whether or not individuals gain excess fat in response to
overeating or not. For example Levine et al. in 1999 overfed a group of
individuals, and found that fat gain was inversely proportional to increasing
levels of NEAT. In fact, these scientists correlated changes in basal metabolic
rate, changes in post feeding thermogenesis and changes in NEAT with fat gain.
No significant correlations were found with the other measures, yet NEAT had a
strong correlation as is seen in figure 2.
Figure
2. NEAT is inversely correlated with fat gain, when individuals are overfed.
Again,
this may be both genetic and environmental. What is known is that obese rats do
not increase NEAT to the extent that lean individuals do in response to
overfeeding.
Another
interesting finding is that during weight loss, much of the decrease in
metabolism seen can be attributed to NEAT. For example, an individual who
weighs more will expend more energy when walking or ambulating (pacing). In a
fascinating experiment Drs Weigle and Brunzell took individuals who had lost
weight and added weighted vests to them. They found that 50 % of the loss in
energy expenditure was made up when the vest was put on. Perhaps along with
calorie cycling during dieting you might try a weighted vest, imagine how great
it would be if your metabolism did not lower or you didn’t hit the dreaded
plateau!
Further,
it appears that as energy intake goes down, NEAT goes down as well. So, the
current working theory is that as excess energy comes in, the human body
regulates it with increased NEAT, or correspondingly decreased NEAT as energy
intake decreases such as occurs during dieting.
How to
apply the NEAT principles to your program for enhanced fat loss
NEAT or
non exercise activity thermogenesis can account for as much as 50 % of the
energy expenditure in activate individuals. Studies show that fat gain and loss
are highly related to NEAT. In fact, it may be that the key to optimally
dieting and sustaining fat loss, is to regulate NEAT levels. NEAT appears to be
a factor of both environment and genetics. Further, when you diet, much of the
loss in energy expenditure or metabolism that you experience is due to lowered
NEAT, either directly through a brain center regulation of activities such as
pacing, and fidgeting, or indirectly related to areas such as carrying less
poundage.
What you
should understand is that regardless of your genetics, you can manipulate NEAT
by how you control your environment. First however you should understand the
impact that NEAT activities have on increasing energy expenditure relative to
resting levels. This can be done by looking at figure 3.
Figure
3. Comparison of energy expenditure of various activities relative to resting
levels of energy expenditure. Adapted from Levine (2004).
As can
be seen activities such as standing are much more energetically costly then
sitting, where as gum chewing can raise energy expenditure 20 % above resting!
Walking 1 mph as occurs when you pace doubles your energy expenditure!
Here are
sample ideas of how you can enhance NEAT.
1.
Instead of sitting in your office, move your computer screen and type writer up
to standing level and spend the day typing while standing. All of a sudden your
“desk job” becomes a standing job, and you will metabolize a substantially
higher amount of calories per day. While it seems strange, I have personally
seen my brother Gabriel adapt easily to this method.
2. When studying or reading a paper, try reading it while ambulating (pacing).
Your energy expenditure will literally double!
3.
Ignore the elevator and take the stairs. You might also not worry too much
about parking right in front of the store. If there’s a parking further away,
take it.
4. Chew gum!
5. When
dieting be extra conscious of NEAT levels as it may be the main reason why you
stop metabolizing fat when you diet.
6. Just
because you can sit, does not mean that you have to sit. I notice that whenever
individuals have a chance to take a load off they do. But while dieting this
may not be the wise thing to do.
The
amazing thing about behavior is that it is modifiable with practice and
experience. If you begin to implement these activities then they will become
second nature, and you will substantially notice yourself becoming leaner.
Conclusion
As the
title suggests Non exercise activity thermogenesis may be the key to Optimizing
fat loss. In fact, I would say that the work of Levine and colleagues is
revolutionary.
Finally, you can see why the crowd was standing, and perhaps why you are as
well!
References
ACSM
conference - Inactivity Physiology and Non-Exercise Activity Thermogenesis D-03
Marc T. Hamilton, University of Missouri (NEAT): Clinical and Molecular Insights
James A. Levine, Mayo Clinic Theodore W. Zderic, University of Missouri -
Columbia
Catherine Kotz, Veterans
Affairs
Medical Center. 2006
Lanningham-Foster L, Nysse LJ, and Levine JA.
Labor saved, calories lost: the energetic impact of domestic labor-saving
devices. Obes Res 11: 1178–1181, 2003
Levine JA, Eberhardt NL, and Jensen MD.
Role of nonexercise activity thermogenesis in resistance to fat gain in humans.
Science 283: 212–214, 1999
Weigle DS and Brunzell JD.
Assessment of energy expenditure in ambulatory reduced-obese subjects by the
techniques of weight stabilization and exogenous weight replacement. Int J
Obes 14, Suppl 1: 69–81, 1990.
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