Energy Systems Flashcards
What enzyme breaks glucose into pyruvates?
Phosphofructokinase. (PFK)
What enzyme breaks pyruvates dow to lactic acid?
Lactate Dehydrogenase (LDH)
What type of performer would use the ATP-PC energy system?
A 100m sprinter or Javelin thrower.
What type of performer would use the Anaerobic Glycolytic energy system?
A 400m sprinter or a 200m swimmer.
What type of performer would use the Aerobic energy system?
A marathon runner or a road cyclist.
Define glycolysis.
When glucose is converted to pyruvate to produce energy.
What is sarcoplasm?
The fluid that surrounds the nucleus of a muscle fibre and is where anaerobic respiration takes place.
How does the ATP-PC system work?
PC > Pi + C + energy
Energy > Pi + ADP > ATP
How long can the ATP-PC system last for?
10 seconds
How much ATP is created from the ATP-PC system?
1.
How long does the anaerobic glycolytic system last for?
3 minutes but can peak at 45 secs.
Name the three parts of the aerobic energy system.
Glycolysis, Krebs cycle, Electron transport chain.
How much ATP is gained from the first part of the aerobic system?
2 ATP molecules.
How much ATP is gained from the second part of the aerobic system?
2 ATP.
How much ATP is gained from the third part of the aerobic system?
34 ATP molecules.
How much ATP is produced from the anaerobic glycolytic system?
2 ATP molecules.
What is EPOC
The amount of oxygen consumed during recovery above the amount that would have been consumed at rest during the same period.
What is meant by the fast component of EPOC?
The restoration of ATP and PC stores and the re-saturation of oxygen in the myoglobin.
How long does it take for PC stores to be restored during the fast component of EPOC?
3 minutes but 50% can be replenished within 30 seconds.
How much oxygen is consumed during the fast component of EPOC to replenish PC stores?
3 litres of oxygen.
How long does it take for the myoglobin to be re-saturated with oxygen during the fast component of EPOC?
Around 2 minutes.
How much oxygen is consumed during the fast component of EPOC to re-saturate myoglobin with oxygen?
0.5 litres of oxygen.
What does the oxygen in the slow component of EPOC do?
Remove lactic acid, replenish glycogen, maintain breathing and HR.
How does oxygen help remove lactic acid?
When oxygen is present, it can be converted into pyruvates which can be used by the muscles as an energy store.
How does oxygen help maintain breathing and HR?
Oxygen restores PC and myoglobin stores allowing the body to return to is pre-exercise state.
How does oxygen help with glycogen replenishment?
Oxygen converts lactic acid back to blood glucose via the Cori cycle.
What is the Cori cycle?
When lactic acid is transported to the liver and turned back into blood glucose and glycogen.
What is lactate accumulation?
When lactate builds in the muscle during high intensity exercise.
How does lactate accumulation affect the athlete?
Lactate slows down enzyme activity causing less glycolysis and therefore muscle fatigue.
How is lactic acid levels measured?
Through blood lactate.
What is meant by lactate threshold?
The point during exercise at which lactic acid quickly accumulates in the blood.
When does the lactate threshold occur?
When the body switches from working aerobically to anaerobically.
What does OBLA stand for?
Onset blood lactate accumulation.
What is OBLA?
The point when lactate levels go above 4 millimoles per litre of blood.
What is the typical lactate threshold of an untrained performer?
50-60% of VO2max.
What is the typical lactate threshold of a trained athlete?
70-90% of VO2max.
How does the exercise intensity affect the rate of lactate accumulation?
The greater the intensity = the faster OBLA occurs.
How does the muscle fibre type affect the rate of lactate accumulation?
Slow twitch fibres produce less lactate than fast twitch fibres.
How does the rate of blood lactate removal affect the rate of lactate accumulation?
If the rate of removal is the same as production, lactate blood concentration will remain the same.
How does the respiratory exchange ratio affect the rate of lactate accumulation?
At a ratio of 1:0, glycogen is the source of fuel and therefore lactate will accumulate quicker.
How does the fitness of the performer affect the rate of lactate accumulation?
A person who trains regularly will have a greater lactate threshold and OBLA will be delayed.
What is buffering?
A process which aids the removal of lactate and maintains acidity levels in the blood and muscle.
How does buffering affect anaerobic performance?
It delays OBLA, allowing for a longer anaerobic performance.
How does an athlete’s body fat % affect their VO2max?
Higher % = lower VO2max
How does an athlete’s gender affect their VO2max?
Men typically have a VO2max 20% higher than women.
How does training affect and athlete’s VO2max?
VO2max can be improved 10-20% after a period of aerobic training.
How does an athlete’s age affect their VO2max?
The older the athlete = typically less VO2max.
Define VO2max.
The maximum volume of oxygen that can be taken up and used by the muscles per minute.
How does an athlete’s lifestyle affect their VO2max?
Poor diet, smoking, sedentary lifestyle, and poor fitness can decrease an athlete’s VO2max.
Name the 4 methods of measuring energy expenditure.
Indirect calorimetry, Lactate sampling, VO2max test, Respiratory exchange ratio (RER)
