The human body works in mysterious ways. So mysterious, that we rarely attempt to understand its many functions. One function it pays to understand is energy production.  When it comes to producing energy for movement, the human body uses three systems. Each system serves a different purpose and during movement they each contribute a percentage of the energy needed to produce that movement. This blog serves to help you better understand these energy systems and how they may affect your training.

What are they?

The first and fastest energy system is the Creatine-Phosphate or ATP-CP System. This refers to stores of energy within your muscles that are ready to be used in a fraction of a second. This system fuels our fight or flight response and acts immediately to provide your muscles with energy for a quick, explosive movement. A heavy single rep deadlift, vertical jump, or swing of a golf club are examples of movements that rely heavily on the ATP-CP system.  This rapid production of energy requires approximately 3-5 minutes to recover and perform again. However, as quickly as this systems kicks in, it will begin to sputter out around 6-10 seconds. As the ATP-CP system runs out of gas the…

Glycolytic System takes on the majority of the workload. This system relies on carbohydrates, or rather glycogen, to produce energy. The glycolytic system will step in as the second responder in energy production and carry you for another minute or so. Riding a half mile on an Assault Bike, pushing a heavy sled, or swinging a kettlebell are examples of movements powered by the glycolytic system. If you have ever done any of the aforementioned exercises, you’ll understand when I say this burns. At such a rapid rate of energy production, this system produces a byproduct that inhibits muscle contraction. We recognize this by the weak knees and burning sensation you get after a kettlebell snatch test or half mile sprint on the bike. To remove this byproduct from the muscles the body turns to…

… The Oxidative System. This system is constantly working. As our glycolytic system begins to fail we pass the torch to the oxidative system, and it burns for a long, long time. Simply put, the oxidative system is breathing, and is the most sustainable pathway of energy production and burning fat. This is the only system that directly requires oxygen and it can power moderately intense exercise for hours. Whether out for a 1 mile jog or racing in an Iron Man, the oxidative system constantly replenishes energy to keep you moving. This system is also the key to recovery during multiple bouts of intense exercise. Take a set of heavy kettlebell swings for example. You may swing for 20 reps without laboring to breathe, but once you put that kettlebell down the huffing and puffing begins. This is your body’s way of restoring energy to the muscles in preparation for another set of swings.