Energy Pathways

Energy Pathways

1. ATP-PC System

   • High intensity (95-100%)
   • 1-6 seconds
   • No oxygen present: we cannot intake as much oxygen as it is quickly required
   • Fuel is Phosphocreatine
     • AKA PC
   • ATP is broken down into ADP+Pi
   • Stored in muscles
   • Fastest rate: lowest yield
   • After 5 seconds: 40-50% of stores depleted
   • 90% restored after 2 mins, 100% after 10 mins

2. Anaerobic Glycolysis

   • Extended high intensity (85%)
   • Main provider for 6-60 seconds
   • No oxygen present. Not enough time to uptake oxygen.
   • Fuel source: carbohydrates
   • Stored in muscles and liver as form glycogen
   • Breaking down glycogen is known as glucolysis
   • Waste product: lactic acid
     • Lactic acid forms in energy pathways when there is no oxygen present

3. Aerobic System

   • Sub-maximal (below 85%)
   • Main provider for 1-120+ mins
   • Carbohydrates are main fuel source
   • Fats are fuel source from 120+mins
     • Fat requires more oxygen to be broken down, however provide more energy (slow rate, high yield)
   • Fatigue occurs as a result of
     • increased body temperature
     • depletion of energy stores
     • Dehydration

4. Interplay

   • Contribute energy sequentially in an overlapping way, depending on the activity and exercise demands
     • ATP-PC
       • 1-6 seconds
     • Anaerobic Glycolysis
       • 6-60 seconds
     • Aerobic energy
       • 1-120+ mins