the energy systems

• Fuel


  Each system has a certain fuel or set of fuels that they use to breakdown ATP
• Rate


  • Speed at which ATP molecules are resynthesised (slow/fast)
  • Depends on fuel + oxygen required (anaerobic vs aerobic)
• Yield


  • Amount of ATP molecules that are resynthesised (high/low)
  • Depends on fuel + fatiguing factors
• Fatiguing factors


  • Inhibit the functioning of the energy system
  • Forces athlete to use another pathway or fuel that produces ATP at a slower rate
  • Leads to a forced reduction in exercise intensity
• Recovery types


  • The reversal of fatiguing factors that have occurred
  • Recovery is done during and after the event
  • Appropriate recovery is required to prepare the system to make an increased contribution again (changes based on the situation)
  • Passive: athlete rests passively e.g. standing/lying down
  • Active: low intensity movement e.g. walking/jogging
• Systems


  • ATP-PC (anaerobic)
  • Anaerobic glycolysis (anaerobic)
  • Aerobic (aerobic)
• ATP-PC system (rapid/explosive activity)


  • Fuel: PC
  • Pathway: anaerobic (no oxygen)
  • Rate: very fast rate (simple chemical structure)
  • Yield: very low yield (PC stores very limited)
  • Fatigue: PC depletion - reduced contribution until PC stores are replenished
  • Recovery: passive
• Anaerobic Glycolysis (high intensity)


  • Fuel: partially breaks down glucose (carbohydrates)
  • Pathway: anaerobic (partially breaks down glucose)
  • Rate: fast rate (partially breaks down glucose)
  • Yield: low yield (due to byproducts)
  • Fatigue: accumulation of metabolic by products
  • Recovery: active (need oxygen to oxidise H+ ions)
• Aerobic system (can use glucose + fats)


  • Glucose (carbohydrates): Fuel: completely broken down glucose, Pathway: aerobic, Rate: moderate rate (uses oxygen + time), Yield: high yield
  • Fats: Fuel: fats, Pathway: aerobic, Rate: slow rate (complex chemical structure + uses lots of oxygen & time), Yield: very high yield (provides the most ATP molecules)
  • Fatigue: glycogen depletion
  • Recovery: Not the same as anaerobic glycolysis + ATP- PC, Does not require you to stop to recover as oxygen is present (recover as you move/go), Active recovery preferred (increases blood flow)