Energy SystemsATP-PC energy

systemLactic acid

energy systemAerobic energy

systemAlternative name

Alactic system, phosphocreatine or creatine phosphate system, phosphagen system

Anaerobic glycolysis, lactacid system

Oxygen system, aerobic glycolysis

Fuel source Phosphocreatine (PC or PCr) or creatine phosphate (CP). Interchangeable names for the same chemical

Glycogen At rest: FFAsDuring exercise: CHO Fats (when glycogen

sparing and when glycogen stores diminished)

Protein (last resort)Intensity of activity

Very High (>95% max HR) High (>85% max HR)Used for increase in intensity in long duration events

RestingSub max intensity (<80% max HR)

Duration system is dominant during activity

1-5 seconds 5-60 seconds >75 seconds

Peak Power 2-4 seconds 5-15 seconds 60-90 secondsAmount of ATP produced

0.7 ATP for each PC molecule

2-3 ATP for each glucose molecule

CHO (38 ATP per glucose molecule)

Fats (441 ATP per triglyceride molecule)

Speed of production

Instantaneous Simple chemical

reactions

Fast Longer chemical

reactions

Medium Complex chemical

reactions Availability of oxygen

delays max powerBy products Inorganic phosphate (Pi)

ADP Lactic acid Hydrogen (H+) ions ADP

C02 H20 Heat

Total duration during activity

0-10 seconds 10-75 seconds >75 seconds