Energy Systems

Energy Systems

1. ENERGY SOURCE - ATP

   • ATP is the only usable form of energy in the body, carbohydrates has to be converted into ATP before the potential energy can be used
   • Sources of energy to replenish ATP
     • Carbohydrates
       • Stored as glycogen in the muscles and converted into glucose
       • Found as glucose within the blood and transported this way
     • Fats
       • Stored as triglycerides in the muscle
       • Converted into free fatty acids and transported this way in the blood
     • Protein
       • Only tends to be used when stores of glycogen are low
   • Carbohydrates and fats are the main energy providers
   • Breakdown of fats to free fatty acids requires more oxygen than the breakdown of glycogen
     • Therefore during high intensity exercise hen oxygen is limited glycogen is the main energy supply

2. ATP-PC

   • High intensity activities lasting less than 10 seconds use predominantly the ATP-PC system
   • It is anaerobic, Phophocreatine is stored in the muscles and broken down to creatine and phosphate by creatine kinase
     • This releases energy for ATP re-synethesis
   • Disadvantages
     • Limited supply of PC in muscle cell - lasts only for 10 seconds
     • Only one mole of ATP can be resythesised one mole of PC
     • PC re-sythesis can take place only in the presence of oxygen (so when exercise intensity has reduced)
   • Advantages
     • It rapidly resynthesis ATP
     • PC stores can be resynthesised quickly
     • No fatiguing by-products

3. LACTATE SYSTEM

   • Used for high intensity activities with a duration of approx 1 minute
   • It is an aerobic system - anaerobic glycolosis
     • Glycogen broken down into pyretic acid - and because there is no oxygen present the pyretic acid is converted to lactate and 2 molecules of ATP form
   • Advantages
     • ATP can be resynthised quickly
     • With oxygen lactic acid can be converted back to liver glycogen or used a s fuel by oxidation
     • It can be used for sprint finish
   • Disadvantages
     • Lactic acid is a by-product - and it denatures enzymes and presents them increasing at a rate which chemical reactions take place so causes fatigue

4. AEROBIC SYSTEM

   • Low intensity exercise - longer than 1-2 minutes
   • Stage 1 - Glycolysis
     • Stage 2 - Krebs Cycle
       • Stage 3 - Electron Transport Chain
       • Pyretic acid enters mitochondria and is converted to Acetyl co enzyme A which then combines with oxalocaetic acid to form citric acid
       • The reactions result in 2 ATP being generated and carbon dioxide and hydrogen being made
     • Glycogen broken down into glucose, then broken down in to pyruvic acid