THE THREE ENERGY SYSTEMS

  1. ATP-PC System (Phosphate System): This system supplies energy (small amount of ATP) for very short durations of up to 10 seconds. This system does not use oxygen nor does it produce lactic acid which means muscles can work at a high rate, but they fatigue very quickly. This system is accessed for activities with very short, powerful movements like a golf swing, a 100 m sprint, or power-lifting.
  1. Anaerobic System (Lactic Acid System): This system supplies energy (moderate amount of ATP) for exercises lasting less than 2 minutes. This system does not need oxygen, which is handy because it takes the heart and lungs some time to get going. The lactic acid is what builds up in the muscle tissue and causes the fatigue and soreness you feel in your exercising muscles. This system is accessed for activities with the intensity and duration of a 400 m sprint, shorter ski races, or a hockey shift.
  1. Aerobic System (Oxygen System): This system supplies energy (huge amounts of ATP) for exercises of long duration (beyond 2 – 4 minutes). By 4 minutes of exercise, the body responds to supply working muscles with much-needed oxygen from the heart and lungs. In a 1km run, this system is already providing approximately half the energy; in a marathon run it provides 98% or more. All distance activities (ex. rowing, running, swimming) depend primarily on the Aerobic System.

ENERGY SYSTEM RECRUITMENT CHART FOR VARIOUS SPORTS

Although all energy systems turn on at the same time, the recruitment of an alternative system occurs when the current energy system is almost depleted. The following table provides an approximation of the percentage contribution (%) of the energy pathways in certain sports.

Sport / % Contribution of
ATP (Phosphate)
System / % Contribution of
Anaerobic (Lactic Acid)
System / % Contribution of
Aerobic (Oxygen)
System
Basketball / 60% / 20% / 20%
Fencing / 90% / 10% / 0%
Field events / 90% / 10% / 0%
Golf swing / 95% / 5% / 0%
Gymnastics / 80% / 15% / 5%
Hockey / 50% / 20% / 30%
Distance Running / 10% / 20% / 70%
Rowing / 20% / 30% / 50%
Skiing / 33% / 33% / 33%
Soccer / 50% / 20% / 30%
Sprints / 90% / 10% / 0%
Swimming 1.5+km / 10% / 20% / 70%
Tennis / 70% / 20% / 10%
Volleyball / 80% / 5% / 15%