Energy Systems

• Aerobic energy system


  Resynthesis of ATP in the presence of oxygen
• Processes involved in the aerobic energy system

  • Glycolysis: Glucose broken down into pyruvic acid
  • Beta oxidation: Stored fat is broken down into fatty acids before being converted into acetyl-coenzyme A
  • Krebs/citric acid cycle: Oxidation of acetyl-coenzyme-A/citric acid
  • Electron transport chain: Transfer of electrons down a carrier chain/hydrogen is oxidised
• Altitude training


  Training at altitude where there is less oxygen. The body adapts by making more EPO which results in more red blood cells to carry oxygen
• Anaerobic glycolytic system


  Resynthesises ATP quickly for up to 3 minutes but produces fatiguing by products
• ATP-PC system

  Fastest energy system at resynthesising ATP due to the limited number of chemical reactions required
• ATP-PC system


  • Can only last 8-10 seconds, however, as it is limited by phosphocreatine (PC) stores
• Electron transport chain


  Transfer of electrons down a carrier chain/hydrogen is oxidised
• Electron transport chain


  Resynthesises 34 ATP and produces water as a waste produce
• Altitude training


  Training at altitude where there is less oxygen. The body adapts by making more EPO which results in more red blood cells to carry oxygen. These additional red blood cells are an advantage for endurance athletes returning to sea level to compete
• Anaerobic glycolysis


  Occurs, resynthesising 2 ATP. With insufficient oxygen available to oxidise pyruvic acid it combines with hydrogen to create lactic acid
• ATP-PC system

  Fastest energy system at resynthesising ATP due to the limited number of chemical reactions required. Can only last 8-10 seconds, however, as it is limited by phosphocreatine (PC) stores
• Energy continuum of physical activity


  Refers to the changing mix of energy systems which provide the ATP required across different activities and durations
• Excess post-exercise oxygen consumption (EPOC)


  Increased rate of oxygen intake following activity, intended to pay back the oxygen deficit
• Excess post-exercise oxygen consumption (EPOC)


  Fast (alactic) component: Oxygen is used for the resynthesis of ATP and PC, and the re-saturation of myoglobin
• Excess post-exercise oxygen consumption (EPOC)


  Slow (lactic) component: Lactic acid is removed via excretion and conversion back to blood glucose via the Cori cycle in the liver
• High intensity interval Training (HIIT)

  Alternating periods of short high intense anaerobic exercise with less intense, aerobic, recovery periods
• Indirect calorimetry


  A technique that provides an estimation of energy expenditure from the amount of carbon dioxide produced and oxygen consumed during rest and steady-state exercise
• Lactate sampling


  A tiny blood sample is taken to be analysed by a device. This measures how much lactate is present in the blood
• Lactate threshold


  The point at which lactic acid accumulates quickly in the blood
• Onset of blood lactate accumulation (OBLA)


  The point at which lactic acid exceeds 4mmols per litre in the blood
• Oxygen deficit


  The difference between the oxygen required during exercise and the oxygen supplied and utilised. Occurs at the onset of exercise
• Plyometrics

  Anaerobic training method based on the concept that muscles contract with more force following an eccentric contraction. Movements such as hopping, bounding, depth jumps are used
• Respiratory exchange ratio (RER)


  The ratio of carbon dioxide produced to the oxygen consumed. A ratio nearer 0.7 suggests the body is using fats as its primary fuel, while 1.0 would indicate carbohydrates
• Speed agility quickness (SAQ)


  This anaerobic method of training aims to improve an athlete's multi-directional movement by reprogramming their neuromuscular system. To do this it utilises equipment such as ladders and cones
• VO2 max


  The maximum amount of oxygen that can be taken in, transported, and used by the body per minute. Measured in millilitres for each kilogram body weight each minute (ml/kg/min)
• VO2 max test


  VO2 max can be estimated using tests such as the multistage fitness test. However, the gold standard is direct gas analysis. In a laboratory the participant will work at increasing intensity, until failure is reached, on a treadmill, static bike, or rowing machine. They do so wearing a mask over their nose and mouth. This is connected to a machine which can measure their oxygen consumption