Energy Pathways and How They Work


Ever feel crummy when you start a workout and then begin to hit your stride, get breathing harder and then everything seems to click better and you can push through the rest of the WOD?

This happens to us due to different energy systems in the body. Here’s a quick breakdown of our three energy systems and how they work. 

  1. Phosphagen – This pathway uses small amount of ATP built up in the muscles as well and the combination of Creatine Phosphate and ATP for energy in the body. Because these energy stores are small, this pathway is utilized for quick, explosive energy such as short sprints. This energy system reaches its maximum capacity in approximately 10 seconds. 
  1. Glycotic – This is an anaerobic pathway, meaning that oxygen is not utilized to create energy for the body. Glucose (sugar from carbohydrates) is used to form ATP for energy, and this energy sources lasts for 30 seconds to a maximum of 3 minutes. 
  1. Oxidative – This is our only aerobic pathway, meaning that oxygen is utilized to create ATP for energy. Fats and carbs are burned in the presence of oxygen for ATP production after the other pathways have been exhausted. Therefore this pathway does not reach it’s maximum capacity until after 2-3 minutes of exercise. 

This diagram shows a breakdown of the maximum capacity of each energy pathway over time.


The oxidative pathway is the one we used for CrossFit WODs most often. As coaches, we want you to be as prepared as possible when going into a WOD to succeed and score well without feeling that crummy sluggish mode of your workout. For short WODs in particular, such as 10 minute AMRAP’s, we want your heart rate up before the workout starts so that you have utilize the oxidate pathway to fuel your workout consistently. 

This is why we do a quick, intense warm up just before starting the WOD. We aren’t just trying to wear you out before the scored workout begins. Trust your coaches. We are here to set you up for success in each and every WOD!

~Coach Deidre~