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Energy System Development

Nov 12, 2013

Energy System Development

What many refer to as “cardio” is better described as energy system development (ESD) because the human body relies on three energy systems to perform exercise; the phosphocreatine, glycolytic, and oxidative. The intensity and duration of exercise will determine which energy system is being utilized; with intensity being the most important factor. The phosphocreatine energy system relies on creatine for fuel. The glycolytic energy system utilizes carbohydrates as fuel and the oxidative energy system burns fat for energy. Various modes of exercise can be used for ESD, such as; running/sprinting, cycling, circuit training, plyometric training and other combinations/variations of the latter. All forms of ESD are generally performed in intervals.

Interval training is the method used to improve energy system development via variations in work, rest ratios and intensity. Too often people perform exercise without variations in the intensity and without rest periods this is known as steady state exercise. Although, steady state exercise has its benefits, especially for sedentary individuals, when it comes to active individuals who want to take their fitness to the next level, interval training is the way to go. Interval training is also a beneficial way to progress sedentary individuals towards longer steady state exercise sessions. For individuals who train regularly, adding high intensity interval training can help them to avoid plateauing.

High intensity interval training, i.e. phosphocreatine and glycolytic energy system development, has been shown to increased individual’s capacity to burn fat. Therefore adding some high intensity interval training to one’s exercise program will not only give them some variety but, over time, it will also improve their performance during steady state/oxidative exercise.

Whether you are sedentary and looking to get yourself active or already an individual who exercises regularly, energy system development via high intensity interval training is something that you should incorporate into your exercise regimen. Listed below are general work to rest ratio guidelines.

Work:Rest ratios for the three energy systems

Phosphocreatine- 1:12 – 1:20

Glycolytic- 1:3 – 1:5

Oxidative- 1:1 – 1:3

To be continued…


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