By Giovanna Chevis
Introduction to Energy Systems
Depending upon the energy necessary to complete a task, the body makes use of several different systems. The body needs energy 24 hours a day, even when sleeping. Energy, in simple terms, is the ability to do work. Work, for its part, can be as simple as digesting, performing a one rep max, or running a marathon.
What Are Energy Systems?
Energy systems are specific pathways through which the body produces and uses energy. Adenosine triphosphate (ATP) is a molecule that provides energy for all movement. The energy systems are designed to generate and use ATP at the same time. However, depending upon the task, one of the pathways will dominate.
Why Training the Three Energy Systems Matters
In other words, energy systems do not function independently. The duration and intensity of the exercise will determine which energy system is to be used. To train effectively and meet the correct stimulus of the workout, coaches should know which energy system is being targeted.
The Three Primary Energy Systems
The three primary energy systems are:
- ATP-PC (Phosphagen System)
- Glycolytic System
- Oxidative System
ATP-PC System: The Immediate Energy Pathway
The first system we’ll explore is the ATP-PC system, also known as phosphagen system or immediate energy system. The reactions happen outside the mitochondria and, because it does not use oxygen, it is said to be anaerobic. It is used for higher intensity exercises and only last up to 30 seconds.
Glycolytic System: Short-to-Mid Range Energy
The glycolytic system is the second energy system used by your body. Glycolysis literally means the breakdown of glycogen. This pathway of creating energy also takes place outside the mitochondrion and utilizes carbohydrate to produce ATP.
Oxidative System: Long Duration Energy
The third energy pathway is the oxidative system. As it is the only aerobic system, it requires the presence of oxygen. While the glycolytic uses carbohydrate to produce ATP, the oxidative system uses two other macronutrients: fat and protein.
How the Three Energy Systems Work Together
The body constantly shifts between all three energy pathways. However, depending upon the intensity and the duration of the activity, one of the systems will be used preferentially.
Training Strategies for the Energy Systems
To train each of the systems requires different strategies. Aside from the intensity and duration of the activity, the rest and recovery time must also be considered. Designing the right stimulus in a workout is essential to make progress.
Conclusion: Maximizing Performance with Energy System Training
Each sport differs in how the different energy systems are recruited. Understanding the energy systems, how they differ, and how to train them is key to improving performance.
References
Gentil Paulo, Energy system contribution during 200- to 1500-m running in highly trained athletes (2021) https://paulogentil.com/pdf/Energy%20system%20contribution%20during%20200%20to%201500%20running.pdf
Goktope A. Salim, Energy Systems in Sports (2018) https://books.google.com/books?hl=pt-BR&lr=&id=z6NyNe3m4AsC&oi=fnd&pg=PA24&dq=ATP+PCR+energy+systems+during+exercise&ots=Yq4C3xDhSt&sig=c8Qqlmn6FqkFTrAoZkklAoRyKxQ#v=onepage&q=ATP%20PCR%20energy%20systems%20during%20exercise&f=false
Baechle TR and Earle RW, Energy System in Sport and Exercise (2015) https://www.sport-fitness-advisor.com/energysystems.html
Hurley Sean, The Aerobic Energy System: What it is, Why it’s Important, and How to Train it, (2020) https://www.trainerroad.com/blog/the-aerobic-energy-system-what-it-is-why-its-important-and-how-to-train-it/
Schmit Leonardo, What Are the Energy Systems (2017), https://leo.fitness/blog/what-are-the-energy-systems-an
