Fire As An Analogy For Your Metabolism

We love the outdoors.  Let’s pretend we’re going on a backpacking trip and sleeping under the stars for a few nights.  Upon reaching our campsite we’re going to need to build a fire for heat and to cook.  Let’s look at the different tools we have to start a fire and then we can compare those to the function of our metabolism.

Note: I got this analogy from a podcast with Peter Attia M.D. and Andy Galpin PhD

Tools For Building a Fire

First, we will need to start off with a match.  When we strike a match, we get a lot of heat (energy) for a very short amount of time.  This is akin to ATP within our muscle cells being used for quick bursts of high energy.

Before the match goes out, we need to transfer the fire (energy) to a medium that will burn a little bit longer.  Lucky for us, we brought some old newspapers along.   The newspaper will burn hot and will burn for longer than a match, but within a few minutes it will also fade and die out.  Think of the newspaper as being glucose/glycogen in our body (glucose is blood sugar and glycogen is sugar stored in muscle and liver tissues).

Once the newspaper is lit, it is in our best interest to put firewood over the top of it and get the firewood to ignite.  Once the wood is lit, it will provide a good amount of heat for a much longer period of time.  The wood is analogous to fat stored around our body.

How Does This Relate To Metabolism?

ATP is the body’s primary source of energy and is already housed within all cells of the body.  For this article we will be talking about muscle cells, as they are one of the biggest drivers of metabolism.  ATP is utilized for energy and converted into ADP when used up.  Cells then convert ADP back into ATP to be used again as energy.

Matches Are Like ATP

In our example, ATP was the original match that we lit.  If we wanted to stay warm and cook using only matches, we would have to light one every few seconds (not a very efficient way to stay warm for a long period of time).  This is how ATP is first utilized in the muscle.  Let’s say you are running a sprint as fast as you possibly can.  Your body will be converting a great deal of ATP into energy to support this high level of energy, but your body can only keep this pace for so long.  Once ATP is depleted and your body can’t convert ADP back to ATP fast enough to keep up with energy demands 2 things will happen: 1) your sprinting pace will slow down and 2) your body will have to begin to convert glucose or glycogen into ATP.

Newspapers Are Glucose/Glycogen

Newspapers were our second form of heat energy in our example.  Hopefully, by the time the match had burnt out we had some newspaper lit.  That newspaper will burn pretty hot and will last us several minutes, but when it burns out we will have to continue to supply more paper.  Newspaper in this example is analogous to glucose/glycogen.  Instead of running a sprint, let’s say you’re running a 400 or 800 meter hard effort.  Most of us could never maintain an all out sprint at that distance, so our pace will be a little slower and we will be relying on glycolysis for energy.  Glycolysis is the conversion of glucose into ATP.

Firewood is Fat

Firewood is fat in our example.  Instead of running 400 meters, let’s say you’re running 2 miles.  You will not be able to hold the same 400 pace for this distance and definitely won’t be able to hold a sprint.  The firewood in our example was providing a moderate amount of heat (energy) for a longer period of time.  This is similar to how fat can fuel our exercise efforts.  At lower intensities and longer durations your cells will convert fat to ATP through a process called oxidative phosphorylation.  Think about a very good marathon runner.  Even though they are running at a very high rate of speed, they are most likely in an aerobic state, meaning they are utilizing *primarily* fat.  (I emphasize primarily, because I am oversimplifying this entire process).  Good endurance athletes have trained their bodies to be very efficient at utilizing fat as energy for those long efforts.

Putting It All Together

The first thing you should understand is that these processes occur in all cells, but to keep it simple we will focus on muscle cells.  If you follow along with our BWCLP you’ll know that we talk a lot about the importance of building muscle.  Muscle is one of the primary drivers of metabolic activity in the body.  Wanna beef up your metabolism?  Build muscle.  This doesn’t mean you need to pack on slabs of muscle like a body builder.  Rather, we suggest shifting the ratio of body fat to muscle in your body to favor lean mass.

In our rudimentary example we covered a few different energy systems.  Now, we will talk about how to improve those systems in a simple way.

Training Your Matches

Even though matches burn really fast, it is still important for us to improve their efficiency.  The best way to do this is through strength training.  (NOT CARDIO WEIGHT CIRCUITS, actual periodized and progressive strength training).  We recommend Strong Lifts and Gymnastics Bodies.  We emphasize not doing cardio weight circuits because those are not strength building exercises, they are aerobic, which we will get to in a minute.

Training Your Firewood

To make your body more efficient at burning fire wood (fat) we strongly recommend doing zone 2 aerobic work.  We have written about zone 2 before, head to this link to check that article out.  TLDR: zone 2 is approximately the level of effort where your body is utilizing a peak amount of fat before shifting over to glycolysis.  It is about the pace where you can still comfortably carry on a conversation and breathe through your nose, but periodically have to stop to take a deeper breath.  (Pro tip: most great runners and endurance athletes spend the majority of their training efforts at this intensity).  Have you ever noticed you get out of breath on a flight of stairs?  Maybe you can only go hiking for short periods of time before getting tired?  Do you have high blood pressure or a high resting heart rate?  Zone 2 needs to become your friend.

Training Your Newspaper

Don’t.  Early in your exercise endeavors there is little reason to focus on those glycolytic intensities.  Develop your aerobic base (fire wood) and your strength (matches) first.  Once you have built those domains, then you can do higher intensities for longer periods of time.

In summary…

Metabolism is a very complicated subject that we try our best to summarize in articles like this.  Despite ti’s complexities, following our simple formula we teach in the BWCLP is a time tested and proven way to begin to shift your body’s efficiency.