by Evan Peikon
What is An Energy System?
Without going too deep down the rabbit hole, our body has three predominant systems used to synthesize (resynthesize) ATP (Adenosine Triphosphate).
1. The Phosphagen System (ATP-CP System).
-This system is anaerobic, meaning that it doesn’t use oxygen as a fuel source.
-Nor does this system use lactate as a fuel source, making it Anaerobic Alactic.
2. The Anaerobic System (Glycolytic)
-Since this system is glycolytic, glycolysis must be performed. Meaning you use sugars as the primary fuel source.
3. Aerobic System (Oxidative)
-As made apparent by the name oxidative system, oxygen is the primary fuel source in this energy pathway.
Common Misconceptions & Why N=1:
Most of you have probably seen this picture before. However, it is not entirely accurate. Energy systems don’t work like light switches where you can just turn one on and another off. All three work simultaneously, albeit to different degrees. A more accurate picture would portray one energy system providing the bulk of energy at the top of the graph, while the other two quietly provide small amounts at the bottom of the percentile graph.
This picture, also from the Crossfit Journal, has even more fallacies than the last. The biggest fallacy I will adress is that regarding the duration of work section, which I will address in more detail later in this article. But for a primer of what I will discuss… Let it be known that just because someone is doing work for a duration of 20 seconds doesn’t mean they are using phosphagen. For all you know they can be going aerobic. If their aerobic system is powerful enough they can even hold a high output sprint for two minutes and it will still be aerobic, NOT glycolytic.
(Also taken from the CFJ) This diagram account for no variation in individual physiology, and just throws blanket statements out. To start, the aerobic system can infact be used to increase power, speed, and strength depending on your makeup. Different things resonate with different people. For example, someone who has a makeup suited for power/speed sports (sports with a high sympathetic nervous system component) may get recovery from weights, and become tanked from aerobics. While someone in an endurance sport (parasympathetic dominant component) may get recovery from aerobic and tanked from hitting the weights. How then can you say that a 30 minute low intensity spin is good active recovery… you cant because its all individual.
My second point. Stating that aerobics burn muscle is just incorrect. Theres the whole hormonal side of the equation that is completely ignored by this statement (which will be an article in and off itself soon). But to give you a starting point you can read this research:
Resistance exercise induced mTORC1 signalling is not impaired by subsequent endurance exercise in human skeletal muscle
Next is the “aids in all sports” claim. Given the direction the “sport of fitness” has headed having a large AEROBIC base is needed to compete at the top level. How else would games competitors sustain such high power outputs in so many workout in such few days. While one can argue that their “high intensity” efforts are glycolytic, it becomes apparent that the top level competitors are actually operating in the oxidative system. Which is made apparent by their “Stoic” looking sustainable and repeatable efforts (see the article on ATP-CP Battery for more on that note).
So What Does This All Mean?
To start, it means that the energy system used isnt determined by the time domain alone. It is determined by the output relative to a specific athlete in that time domain.
Lets take a 19 year old 3200m Runner and throw him on an airdyne.
Now we have him do a 60 second sprint and he sustains 550-600 watts.
Now we have him do a 20 second sprint and he sustains ~600 watts.
If we used the time domain concept alone it would mean that he would have been operating in the Glycolytic system on the first interval and the Alactic on the second. However, he was most likely operating in the aerobic system since he cannot physically tap into the Alactic system (since he is so aerobically dominant).
If this is the case, it would take months of training to teach his nervous system to put out a high enough power output to actually tap the Alactic system fully.
Now an example on the other extreme:
This time we have an extremely powerful athlete, say a 50m Sprinter.
We have him do a 20 seconds all out Airdyne Sprint.
Using the chart alone it would tell us he is in the Alactic system. However, this athlete may be so grossly powerful that he actually starts tapping into the anaerobic lactic power system.
Now for the application in regards to training athletes.
The aforementioned information is a perfect example of why every athlete should have a program specifically tailored to their individual needs. Without knowing exactly how an atheltes body work your just blindly throwing darts when assigning workouts. You know the 12 week lactic endurance cycle you just did… well what if your athlete was actually taping the aerobic system the whole time? Well, then you just wasted three months that could have been better spent working towards allowing the athlete to tap that energy system.
By creating a Coach-Athlete dynamic where they are constantly providing feedback to one another it becomes possible to better understand that athletes unique engine and figure out how to effectively program time domains, intensities, rest etc to best suite that athlete.
Until you do so, your leaving room to improve on the table….
Hence the Article title N=1. You are your own experiment, an individual, and until you start to figure out what you’re made of you are just guessing.
(As an additional statement, this is another reason not to follow a general blog programing site. It is NOT written for you and therefore you may not be getting the intended stimulus).
*In our Exclusive Coaching program we test different energy systems in order to see what resonates with an athlete, as well as what their strengths/weaknesses are. Then via weekly feedback we can progress through training an energy system by seeing how an athlete responds to a given dose prescribed at a given intensity (in a certain time frame).