Those who have studied exercise or kinesiology, or maybe even simple biology, have more than likely heard the term energy systems before. It seems though that the more someone reads about them - the more confused they become.
The explanations you hear the most will usually be filled with jargon like Krebs Cycle, anaerobic, mitochondrial respiration, glycolysis, ATP, etc.
You don't need a Masters in Kinesiology to understand energy systems though! Gaining a better understanding of how energy systems work can help you improve performance and optimize diet and training to support the different energy systems you use.
Think about this for a moment - have you ever wondered why your muscles begin to burn and ache, and you lose breath on high rep exercises?
Or why most people suggest high carb intake for high intensity athletes?
This article will help you better understand why that is the case.
First things first - What is an Energy System?
An energy system is the process used by your body to transform your food and your body in to energy that it can use to perform a physical task. The cells that make our bodies go use many different sources of energy for many different tasks.
Once you have eaten a meal, your body breaks down the energy that came from the food. Protein, carbs, and fats become smaller molecules.
The Amino Acids you get from your protein intake are mostly used as building blocks of cells that are rarely used as an energy sources. Sometimes the body will convert a small set of amino acids in to glucose if it needs to burn protein as the main energy source for its activity. This is a very inefficient process and for the most part we can ignore protein as a source of energy.
Glucose is most often used immediately and is recommended to be ingested closer to the time of your physical activity. When the carbs/sugars are broken down to glucose they form large bundles of molecules called glycogen - which is stored in the liver and muscles. The body then pulls the glycogen out of storage during exercise and uses it as energy.
Triglycerides are most often stored in body fat if not used immediately. Keep in mind, fat is not a bad thing. Too much will obviously create problems, but having a 0% body fat would create a very unhealthy body. We use fat as energy only when we need it, again, because glucose is what the body would prefer to use.
Your body's energy systems are responsible for making sure that your cells have a steady supply of energy no matter if you are asleep, watching tv, or competing in an Iron Man competition. As you can imagine, keeping your cells stocked with energy can be difficult and very complex for your body to do. This is why it relies on multiple systems.
An energy system is a physiological process that describes the body converting food to energy, and energy to activity. If you want to perform a personal experiment, try these three ideas.
1. Do 2-3 low intensity cardio workouts each week.
2. Do 1-2 high intensity cardio workouts per week.
3. Perform 3-4 maximum strength resistance workouts per week.
You will begin to notice that your body responds differently to each of these workouts, and it is for no reason other than the usage of all the energy systems. Each workout regimen is designed to target different energy and produce different results.
Give it a try and let us know what you think! If you enjoyed this article share it on Twitter, Facebook, IG, or wherever else!