First, we want to thank you for your interest in Eat To
Perform and our Free Mini Course. Dr. Mike T Nelson
wrote this tips as simple introduction on how performance
based fat loss works. Our Meal Planning Guide ($14.95)
was written with these principles in mind and makes things
drop dead easy to understand.
Tip 1: An Overview of How “Met Flex” Works on a
High Level
At the ground floor, you want to be able to use both fats and
carbohydrates for fuel during activity. During lower
intensity activity such as walking and moving around doing
your daily job, your body is designed to use fat as its primary
fuel source.
When you exercise, especially at higher intensity levels, you
want the ability to shift into using carbohydrates. Using
carbohydrates during exercise will actually result in
improved exercise (or athletic) performance.
Tip 2: How to Shift Between Using Carbs and Fat for
Fuel
Metabolic Flexibility enables you to do two things:
(1) transition between fat and carbohydrate metabolism so
you can burn more fat when you're not exercising; and
(2) use carbohydrates when you are exercising to fuel that
activity and perform at a higher level.
When we eat food, our body breaks it down into fuel. The
main sources of fuel are carbs and fats (protein is generally
not used directly for fuel).
We can measure this in the lab with fancy equipment called a
metabolic cart that will tell us what “fuel mixture” your body
is using at that time via the respiratory exchange ratio (RER).
Both fuels are needed for optimal body composition and
performance. When you are doing high intensity exercise,
carbs are the best fuel. The rest of the time, you want to be
a fat burning machine, thus your overall RER is low (pushed
towards using fats).
Metabolic Flexibility is the process of turning your body
into a fuel shape-shifter.
Carbs can be used directly or stored as glycogen for later use
during exercise, while fat (both dietary fat and body fat) can
be burned at a higher rate the rest of the time. This way
you get the performance you want in the gym, but the body
composition you want at the beach.
Let's get to tip #3, which is a concept that has helped open
the eyes of some of the greatest athletes in the world, as well
as everyday people seeking a simple, proven approach.
Tip 2:
Why Carbs Are NOT "Evil"
This is a very commonly held belief in the fitness media
today, and for good reason. Carb consumption can
POTENTIALLY get out of hand, but active people have
a tremendous advantage. My preference is to have
some carbs (and protein) before training if it is possible.
Why?
When you consume carbs (and some proteins), insulin
levels go up. Insulin is the fuel selector switch. When
it is higher, it shifts your body to use carbs. As you
know, carbs are the preferred fuel for high intensity
exercise. This way you are matching your nutrition to
your training.
“But what if I exercise early in the AM?”
I totally understand that some train in the early AM and
getting in much of any food is not possible. Don’t
worry, as all is not lost.
Your body has stored carbohydrates in the form of
glycogen in the muscles and liver. As long as your
stores are adequate, you can still fuel your exercise
session.
Summary
Metabolic flexibility is all about using the right fuel at the
right time. Your body is brilliantly designed to use
stored glycogen for training when you can’t consume
any carbs beforehand.
If you can get in some carbs before an intense exercise
session, go for it. If you can’t, you will still be fine.
Tip 4: Don't Be Afraid of Carbs. Here's Why...
It seems that many people are afraid of carbs. The
media has convinced them that they are bad. I
disagree. Remember that the media once said all fats
were bad too - so are eggs, milk, etc. Bah!
Carbs are the preferred fuel source for high intensity
exercise. It is a bioenergetic fact that you can NOT
produce the same levels of power by only using fat as
an energy source. This is in every basic exercise
physiology textbook.
I am a big fan of having some carbs before training if at
all possible. I know some lift in the AM fasted as it is
impossible to get anything down beforehand, and that
is fine. If you have time though, take in some starchy
carbs before your training session, starting at around
50 grams.
Good choices are sweet potatoes, bananas or
prepackaged carb sources like Vitargo.
Not only will you have the fuel to use during training,
but they promote the release of insulin by your
body. Insulin is not the devil it has been portrayed and
higher levels of insulin actually push the body to use
more carbs. This is exactly what you want to do during
training.
If you have not tried this before, please try it first on a
non-training day or time to see how your body reacts.
Summary
Try adding some starchy carbs pre-training if at all
possible. If you are training in the AM fasted, push
your carb intake to the night before. Most people see
a nice bump in their performance.
Tip 5:
Are You Fueling Your Body Properly?
While it seems hard to believe, a vast majority of your
calories are spent just running your body. The geeky
term is “resting metabolic rate” (RMR). RMR is the
amount of calories it takes to fuel your body while you
lay there and do nothing but breathe.
Since your RMR contributes the largest portion of your
daily “caloric drain” it makes sense to fuel most of it
with your own body fat!
Note – If you are interested in an estimate of how
many calories you need, make sure to check out the
Eat To Perform TDEE calculator. The downside is that if you chose to use ONLY fat,
your ability to perform high intensity exercise would
suck. Not good.
Therefore, you still want to be able to up-shift and
use carbs to fuel your exercise sessions.
As soon as you are done, shift back to using fat again.
Metabolic flexibility (Met Flex) is all about shifting from
one fuel source to the next and back.
Summary
The simplest way to describe Met Flex is that it’s a
strategy built around shifting your RMR to burn mostly
body fat as well as dietary fat. You still allow your
body to up-shift to a carbohydrate metabolism for
performance.
Improved performance translates into more muscle;
more muscle translates into an increased RMR, and an
increased RMR means less body fat.
Boom! You get the best of both worlds without all the
hassle.
Tip 6: Eat More and Still Look Lean
Everyone is looking for a way to eat more (or feel like
that ate more) and still get leaner. Ok, I will put my
hand down now too.
One mechanism you can look at to get some insight
into this question is the concept of “Dietary Induced
Thermogenesis” (DIT).
Sounds complex, but it is pretty easy to grasp.
Whenever you eat, your body needs energy to digest
your food. Some foods use more energy, so your net
energy intake is a bit less. This is not a huge
component of your total energy expenditure, but around
3-10% and can add up over time.
In a study from 20087 by Tentolouris et al., they
investigated this in lean and obese subjects.
They found that protein has a 3xs greater DIT than fat,
so over eating protein in the end should help weight
loss via that mechanism. It is taking much more
energy to “process” protein (and it fills you up faster
too).
What was interesting is that contrary to popular belief,
there was not any difference between obese or the lean
subjects.
Regardless of your current body fat level, the effect is
about the same.
Another reason to fill up on protein!