energy systems

• ATP


  Energy released from the breakdown of ATP provides the energy for muscular contractions to occur
• ATP resynthesis


  The body only has a limited supply of ATP so must constantly resynthesize (remake) ATP
• Role of Energy Systems

  To resynthesis ATP to support ongoing muscular contractions
• Energy systems


  Powered by both chemical and food fuel sources
• Phosphorylation


  The process of re-joining P to ADP to make ATP
• Food Fuels


  • Fats
  • Carbohydrates
  • Protein
• Fats


  • Food Sources: Avocado, Nuts & Cheese
  • Stored as Triglycerides (Adipose Tissue)
  • Transported as Free Fatty Acids
  • High Yield of ATP Produced
  • Large Stores Available
  • Complex Chemical Reactions
  • Large Amounts of Oxygen Required
• Carbohydrates


  • Food Sources: Bread, Pasta & Fruit
  • Stored as Glycogen (Muscles & Liver)
  • Transported as Glucose
  • Anaerobic & Aerobic Pathways
  • Less Oxygen Required
  • Simpler Chemical Reactions
  • Limited Storage Within The Body (90min- 2 hours)
  • Smaller Yield of ATP Produced
• Protein


  • Food Sources: Lean Meats, Chicken & Fish
  • Major Role: Repair & Growth of Muscle Tissue, Support Essential Bodily Functions
• ATP-PC Energy System


  • Fuel: Intramuscular ATP & Phospho-Creatine
  • Rate: Extremely Fast Rate
  • Yield: Extremely Low Yield
  • Dominant Duration for Maximal Activity: 0 – 10 Seconds
  • By-Products: ADP, Inorganic Phosphate
  • Fatigue: 0-2 Seconds Depletion of Intramuscular ATP, 3-10 Seconds Depletion of Phospho-Creatine
  • Recovery - Passive: 30 Seconds 70% of ATP Resynthesis, 3 Minutes 97-100% of ATP Resynthesis
  • Activities: 100m Sprint, Shot-Put, Javelin, 25m Freestyle
• Anaerobic Glycolysis System


  • Fuel: Glycogen – Glucose - Carbohydrates
  • Rate: Fast Rate
  • Yield: Moderate Yield
  • Dominant Duration for Maximal Activity: 10 - 60 Seconds
  • By-Products: Lactate, Hydrogen Ions
  • Fatigue: Build up of metabolic by-products, H+ attach to key areas of the sarcomere and inhibit muscular contraction
  • Recovery - Active: Remove By-Products, Increases blood flow and presence of oxygen to remove metabolic by-products
  • Activities: 400m Sprint, 45 Second AB Sprint, Repeat Leads in Football, 100m Freestyle Swim
• Aerobic Energy System


  • Fuel: Glycogen – Glucose – Carbohydrates, Triglycerides – Free Fatty Acids – Fats, Amino Acids - Protein
  • Rate: Slow Rate
  • Yield: High Yield
  • Dominant Duration for Maximal Activity: 60 Seconds Onward
  • By-Products: H20, CO2, Heat
  • Fatigue: Depletion of Glycogen 2+ hours, Leads to the use of fats as dominant fuel, Thermoregulatory Fatigue, Dehydration, Thicker blood/ harder to pump, Redistribution of blood away from muscles (Vasoconstriction/Dialation)
  • Recovery - Active: Remove By-Products (^ AG contribution), Prevent Venous Pooling, Resynthesis Energy Substrates
  • Activities: Marathon, 5000m Run, Team Sports
• Cardiovascular Responses


  • Increased Heart Rate (HR), Increased Stroke Volume (SV), Increased Cardiac Output (Q), Increased Systolic Blood Pressure, Redistribution of Blood Flow, Increased AVO2 Difference
• Respiratory Responses


  • Increased Respiratory Rate (RR), Increased Tidal Volume (TV), Increased Ventilation (V), Increased Pulmonary Diffusion, Increased Oxygen Uptake
• Muscular Responses


  • Increased Muscle Temperature, Increased Enzyme Activity, Increased Motor Unit Recruitment, Decreased Energy Substrates, Increased O2 Supply & Use, Increased AVO2 Difference
• Lactate Inflection Point (LIP)


  • The final point of balance between the production and removal of lactate, usually occurs at approx. 85% Max Heart Rate/4mmol of Blood Lactate
  • Exceeding LIP will result in the exponential increase in lactate and hydrogen ion accumulation, leading to the onset of fatigue
  • Having a higher LIP results in the athlete being able to work at a higher intensity, aerobically for a longer period of time, improving performance
• Oxygen Deficit


  A period of time where oxygen demand exceeds oxygen supply, anaerobic energy production meets the shortfall
• Steady State


  A period of time where oxygen supply is equal to oxygen demand, aerobic energy systems is able to fully meet energy demand
• EPOC


  The period of time after exercise where heart rate remains elevated above pre-exercise levels, functions include: Restore PC and Intramuscular ATP, Removal of Metabolic By-Products, Restore o2 to Myoglobin & Convert additional lactate back to glycogen
• lactate threshold is the point at which blood lactate levels increase rapidly due to insufficient aerobic capacity