basic energy system

• ATP

  High-energy compound for storing and conserving energy
• Adenosine triphosphate (ATP)

  • Consists of adenine, ribose, and three linked phosphates
• Breakdown (Hydrolysis)

  1. ADP + Pi + Energy

  2. ATP + H2O
• Synthesis (Removal of H2O)

  1. ADP + Pi + Energy

  2. ATP
• Enzyme ATP-ase can weaken & break last PO4 bond releasing energy & free PO4
• Movement classifications

  • Quick movements-lasts a few seconds
  • Reduced speed-lasts for several minutes
  • Reduced intensity(50%)-lasts for several hours
• Cellular energy

  Depends on duration and intensity
• Energy systems


  • ATP-PCr (Alactic Anaerobic Energy system) (10-15s)
  • Glycolytic (Lactic Anaerobic Energy System)(2-3 mins)
  • Aerobic system (>3 min)
• ATP-PCr System


  1. ATP breakdown (4 s)

  2. Phosphocreatine (PC) breakdown (10s)

  3. ADP + Pi + Energy

  4. ADP + Pi + Energy

  5. ADP + Pi + Energy

  6. ADP + Pi + Energy
• Without oxygen presence (anaerobic)
• ATP breakdown


  Produces adenosine diphosphate (ADP) and one single phosphate (Pi)
• Phosphocreatine (PC) breakdown


  Creatine + Pi
• ADP and Pi rejoining


  Forming more ATP
• 1 mole of ATP is produced per 1mole of PCr
• ATP-PCr System


  • Lasts 10 - 15 seconds
  • Produce rapidly
  • For explosive movement , powerful activities eg. 100 m sprints, jumping, throwing, weight lifting
• Recovery


  1. Replenish

  2. Takes 2-6 min

  3. If activity continues at a high intensity these stores may only partially replenish
• Training the ATP-Pcr System


  • Power training
  • Speed training: faster/same speed than used in sports
  • Adequate rest (at least 2 min)
  • 'Work to rest ratio'- 1:10/12
• Glycolysis


  The breakdown (lysis) of glucose /glycogen, controlled by enzymes in the absence of oxygen
• Glycolytic (Lactic Anaerobic)


  • Takes longer (slower muscle contraction)
  • Greater ATP production
  • Involved breakdown of food source
  • Byproduct - lactic acid , no oxygen, muscle fatigue
  • Lasts 2 – 3 minutes
  • Eg. 400 m sprint
• Glucose


  2ATP + 2LA (digested component of carbohydrates)
• Glycogen


  3ATP + 2LA (the storage form of glucose)
• Steps in Glycolytic


  1. Initially glucose in the blood or glycogen stores to be broken down by a series of enzymes into glucose-6-phosphates

  2. Further break down to pyruvate and hydrogen ions

  3. ATP are used to fuel glycolysis and 4 are created so the body gains 2 ATP to use for muscular contraction

  4. This system is 'anaerobic' there isn't oxygen to break down pyruvate and synthesise anymore ATP
• Nicotinamide adenine dinucleotide (NAD)


  Transport hydrogens and associated electrons
• Flavin adenine dinucleotide (FAD)


  Transport hydrogens and associated electrons
• Lactate


  Formed when hydrogen ions (H+) are released into the muscle cell during glycolysis and cannot be transported to the mitochondria due to lack of oxygen
• If a muscle cell becomes too acidic, muscle stops functioning as the enzymes not able to function
• Lactate is removed from the muscle cell to enable exercise to be continued for a little longer
• Lactate that is removed from the muscle is carried to surrounding muscles that have oxygen available and also to the liver where it is converted back to pyruvate and or glucose for further glycolysis and energy production via the aerobic energy system (Cori Cycle)
• Training the Glycolytic System

  • Aim to increase tolerance to lactate, the removal of lactate and improving the rate at which glycolysis produces ATP
  • For full recovery : ratio of 1:6 (6 seconds of rest for every second of work)
  • A ratio of 1:3 - to greater lactate response (some fatigue carried into the next set)
  • This helps to condition the body to clear (get rid of) lactate
  • 1:1 or 2:1 ratio – lactate tolerance
• Glycolytic processes


  • Glycolysis—Breakdown of glucose; may be anaerobic or aerobic
  • Glycogenesis—Process by which glycogen is synthesized from glucose to be stored in the liver
  • Glycogenolysis—Process by which glycogen is broken into glucose-1-phosphate to be used by muscles
  • Gluconeogenesis- Formation of glucose from non carbohydrate source (liver)
• The liver


  1. Goes through various chemical reactions

  2. Convert it back to pyruvate and or glucose for further glycolysis and energy production via the aerobic energy system (Cori Cycle)
• Training the Glycolytic System

  • Aim to increase tolerance to lactate, the removal of lactate and improving the rate at which glycolysis produces ATP
  • For full recovery : ratio of 1:6 (6 seconds of rest for every second of work)
  • A ratio of 1:3 - to greater lactate response (some fatigue carried into the next set)
  • This helps to condition the body to clear (get rid of) lactate
  • 1:1 or 2:1 ratio – lactate tolerance
• Glycolysis


  Breakdown of glucose; may be anaerobic or aerobic
• Glycogenesis


  Process by which glycogen is synthesized from glucose to be stored in the liver
• Glycogenolysis


  Process by which glycogen is broken into glucose-1-phosphate to be used by muscles
• Gluconeogenesis


  Formation of glucose from non carbohydrate source (liver)
• Oxidative System


  • Relies on oxygen to breakdown fuels for energy
  • Produces ATP in mitochondria of cells
  • Yield much more energy (ATP) than anaerobic systems
  • Working sub-maximally at 60 – 80% of maximum effort
  • Involved in endurance events
  • Involved in aerobic glycolysis and fat oxidation
• Oxidative System


  1. Aerobic glycolysis

  2. Krebs cycle

  3. Electron transport chain
• Acetyl CoA


  Pyruvate from glycolysis is converted to acetyl coenzyme A by removing CO2, H+, NAD+, FAD
• Krebs Cycle


  • Two carbons enter in the acetyl fragment of Acetyl CoA
  • Produces CO2
  • Coenzymes are reduced: 3 NADH and 1FADH2 are produced
  • One ATP molecule is produced by substrate level phosphorylation
  • Oxaloacetic acid is regenerated
  • For every glucose molecule split during glycolysis, two acetyl fragments are produced. Thus, it takes 2 turns of the cycle to complete the oxidation of glucose
  • 6 NADH and 2 FADH2 (per glucose) carry high energy electrons to the electron transport chain where ATP is produced by chemiosmosis
  • Most of the ATP output of respiration results from this oxidative phosphorylation