Using Your Three Energy Systems to Your Advantage


Part of the Professionalism for Performance Series


Dr. Timothy Baghurst


Your fitness is determined by how well your body can use the energy it has available. Many of us have plenty of available energy stored as fat, but the ability of the body to convert those stores into useable energy during an intense sport like racquetball is limited.

There are three energy systems working within your body, and they work interactively to produce energy. Which system is working the hardest depends on what your body needs at that moment. Think of each energy system like a rechargeable battery. Once the battery is drained, it needs time to recharge, but each “battery” has a different storage limit and produces different types of energy. Here is a general overview of each.


ATP-PC system (adenosine triphosphate-phosphocreatine system)

  • An immediate energy provider that only lasts about 10 seconds
  • Often used in explosive sports like the 100 meters (or racquetball)
  • Once you use it, your body needs time to replenish its stores
  • It takes at minimum 3 minutes to build back most of the storage (5 ideally)

Glycolysis system

  • It relies on sugar to create energy
  • Stores can last between 45 seconds and 3 minutes depending on the intensity
  • Think of sports where speed and endurance are necessary like the 800 meters
  • Both the ATP-PC system and glycolysis system are referred to as anaerobic energy, as the body can use this energy without requiring oxygen at the time

Oxidative system or Aerobic system

  • This system requires oxygen to convert stored energy into a usable resource
  • The conversion can be accomplished by converting carbohydrates (aerobic glycolysis) or fat (beta-oxidation) into a usable form of energy
  • It takes your body longer to do both of these, but means you can exercise for a very long period of time
  • Slow activities such as walking use this system (although fitter people may use this system for longer before switching over)
  • This system will only take over (i.e., be used the most) if your body is depleted of its anaerobic energy (sometimes called “hitting the wall”)

Your body can use all of these systems simultaneously depending on the situation, but racquetball uses anaerobic energy almost exclusively.

Understanding when you (or your opponent) might need time to replenish these stores gives you an advantage in that situation! For example, if your opponent has had one or two very hard points in which they had to be explosive, their anaerobic system is struggling. Do not give them time to recover, and continue play as soon as possible. They will be a little slower around the court because their body needs time to recharge that fast system. Conversely, if you find yourself on the opposite side of that same situation, use your timeouts and breaks between points to provide you with the time you need to recover.

In a long match, you do not want to rely on your aerobic system for energy, as it takes longer to convert this energy into a useable source and you will be slower as a result. Therefore, do not forget to consume carbohydrates during the match so that your body has anaerobic fuel readily available.