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A-level PE > 1.1 - Energy systems > Flashcards

1.1 - Energy systems Flashcards

1
Q

Where does the energy we use for muscle contractions come from?

A

Adenosine triphosphate (ATP)

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2
Q

What does ATP consist of?

A

One molecule of adenosine and three phosphates.

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3
Q

How is the energy that is stored in ATP released?

A

By breaking down the bonds that hold this compound together.

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4
Q

What is adenosine triphosphate?

A

The only usable form of energy in the body.

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5
Q

What breaks down ATP?

A

An enzyme called ATPase

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6
Q

What is ATPase?

A

The enzyme that is used to break down ATP.

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7
Q

What does ATPase break down ATP into?

A

Adenosine diphosphate (ADP) and an inorganic phosphate (Pi).

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8
Q

How can we resynthesise ATP?

A

From three different types of chemical reaction fuelled by either food or a chemical called phosphocreatine which is found in the muscles.

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9
Q

What are the 3 energy systems?

A

The aerobic system, the ATP-PC system, the anaerobic glycolytic system (lactic acid system).

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10
Q

When are the 3 energy systems used?

A

ATP-PC system = <10s
Lactic acid system = 10s-3mins (depending on intensity).
Aerobic system = >3mins

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11
Q

When is the aerobic system used?

A

When exercise intensity is low and oxygen supply is high.

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12
Q

How much energy can be produced by the complete oxidation of glucose in the aerobic system?

A

36-38ATP.

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13
Q

How many stages are there to the aerobic system?

A

3

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14
Q

What are the 3 stages of the aerobic system?

A
  1. Glycolysis.
  2. Krebs cycle.
  3. Electron transport chain.
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15
Q

What is glycolysis?

A

A process in which glucose is converted to pyruvate to produce energy.

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16
Q

Where does glycolysis take place?

A

In the sarcoplasm of the muscle cell.

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17
Q

Explain the first stage of the aerobic system

A

Glycolysis:

  • Anaerobic so takes place in the sarcoplasm of the muscle cell.
  • It is the breakdown of glucose to pyruvic acid.
  • For every molecule of glucose undergoing glycolysis, a net of two molecules of ATP is formed.
  • Phosphofructokinase is added to convert the glycogen to glucose.
  • If there is no oxygen present, then the pyruvic acid is turned into lactic acid.
  • Pyruvic acid is then oxidised into two acetyl groups and is then carried into Krebs cycle by coenzyme A.
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18
Q

What is the first stage of the aerobic system?

A

Glycolysis.

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19
Q

What is the second stage of the aerobic system?

A

Krebs cycle.

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20
Q

What is the third stage of the aerobic system?

A

Electron transport chain.

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21
Q

What is the sarcoplasm?

A

The fluid that surrounds the nucleus of a muscle fibre and is the site where anaerobic respiration takes place.

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22
Q

What is Krebs cycle?

A

A series of cyclical chemical reactions that take place using oxygen in the matrix of the mitochondrion.

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23
Q

Explain the second stage of the aerobic system

A

Krebs cycle:

  • The two acetyl groups diffuse into the matrix of the mitochondria and a complex cycle of reactions occurs.
  • The acetyl groups combine with oxaloacetic acid, forming citric acid which releases 2 ATP.
  • Hydrogen is removed from the citric acid and the rearranged form of citric acid undergoes ‘oxidative decarboxylation’ which means carbon and hydrogen are given off.
  • The carbon forms carbon dioxide which is breathed out.
  • The hydrogen is taken to the electron transport chain.

Beta oxidation can also provide fuel for the Krebs cycle.

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24
Q

Explain the third stage of the aerobic system

A

The electron transport chain:

  • Hydrogen is carried to the electron transport chain by hydrogen carriers.
  • This occurs in the cristae of the mitochondria.
  • The hydrogen splits into hydrogen ions and electrons and they are charged with potential energy.
  • The hydrogen ions are oxidised to form water (so oxygen is required).
  • The electrons provide the energy to re-synthesise ATP.
  • This process forms and releases 34 ATP.
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25
Q

What are other energy sources that are used aerobically?

A

Fats (fatty acids) and proteins (amino acids) can be broken down under aerobic conditions to provide energy for us to exercise. These can both enter the Krebs cycle and eventually the electron transport chain to produce ATP.

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26
Q

What can also enter the Krebs cycle to help produce ATP?

A

Fatty acids and amino acids that are broken down.

Also stored fat that is converted into acetyl coenzyme A by beta oxidation.

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27
Q

Explain what Beta oxidation is

A

Stored fat is broken down into glycerol and free fatty acids for transportation by the blood. The fatty acids can then undergo beta oxidation where they are converted into acetyl coenzyme A, which is the entry molecule for the Krebs cycle. From this point on, fat metabolism follows the same path as glycogen metabolism and more ATP can be produced from fatty acids than glucose so they become the predominant energy source in low intensity, long duration exercise.

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28
Q

What are the advantages of the aerobic system to provide energy?

A
  • More ATP can be produced; 36-38 ATP.
  • There are no fatiguing by-products (carbon dioxide and water only).
  • Lots of glycogen and triglyceride stores so exercise can last for a long time.
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29
Q

What are the disadvantages of the aerobic system to provide energy?

A
  • It is a complicated system so can’t be used straight away. It takes a while for enough oxygen to become available to meet the demands of the activity and ensure glycogen and fatty acids are completely broken down.
  • Fatty acid transportation to muscles is low and also requires 15% more oxygen to be broken down than glycogen.
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30
Q

What is the electron tranpsport chain?

A

Involves a series of chemical reactions in the cristae of the mitochondria where hydrogen is oxidised to water and 34 ATP are produced.

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31
Q

What is phosphocreatine (PC)?

A

An energy-rich phosphate compound found in the sarcoplasm of the muscles and can be broken down quickly and easily to release energy to re-synthesise ATP.

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32
Q

What is the ATP-PC system?

A

An energy system using phosphocreatine (PC) as its fuel.

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33
Q

How does the ATP-PC system work to provide energy?

A
  • It is an anaerobic process and re-synthesises ATP when the enzyme creatine kinase detects high levels of ADP.
  • It breaks down the phosphocreatine in the muscles to phosphate and creatine, releasing energy.

Phosphocreatine (PC) –> Phosphate (Pi) + Creatine (C) + Energy.

  • This energy is then used to convert ADP into ATP in a coupled reaction.
  • For every molecule of PC broken down, there is enough energy released to create one molecule of ATP.
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34
Q

Is the ATP-PC system aerobic or anaerobic?

A

Anaerobic.

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35
Q

Write the equation for the production of energy in the ATP-PC system

A

Phosphocreatine (PC) –> Phosphate (Pi) + Creatine (C) + Energy.

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36
Q

What are the advantages of the ATP-PC system?

A
  • ATP can be re-synthesised rapidly using the ATP-PC system.
  • Phosphocreatine stores can be re-synthesised quickly - [30 s = 50% replenishment and 3 mins = 100%].
  • There are no fatiguing by-products.
  • It is possible to extend the time the ATP-PC system can be utilised through the use of creatine supplementation.
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37
Q

What are the disadvantages of the ATP-PC system?

A
  • There is only a limited supply of phosphocreatine in the muscle cell, i.e. it can only last for 10s (5-8s).
  • Only one molecule of ATP can be re-synthesised for every mole of PC.
  • PC re-synthesis can only take place in the presence of oxygen (i.e. when the intensity of the exercise is reduced).
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38
Q

What does anaerobic mean?

A

A reaction that can occur without the presence of oxygen.

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39
Q

What is a coupled reaction?

A

When energy required by one process is supplied by another process.

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40
Q

What is the short-term lactate anaerobic system (lactic acid system)?

A

Produces high powered energy for high intensity effort in events such as the 400m.

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41
Q

What is the short-term lactate anaerobic system (lactic acid system) also called?

A

The anaerobic glycolytic system.

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42
Q

How long the short-term lactate anaerobic system (lactic acid system) lasts depends on what?

A

The fitness of the individual and how high the exercise intensity is.

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43
Q

How does the short-term lactate anaerobic system (lactic acid system) work to provide energy?

A
  • When the PC stores are low, the enzyme glycogen phosphorylase is activated to break down the glycogen into glucose, which is then further broken down to pyruvic acid by the enzyme phosphofructokinase..
  • This process called anaerobic glycolysis takes place in the sarcoplasm of the muscle cell where oxygen isn’t available.
  • Because it is an anaerobic process the pyruvic acid is then further broken down into lactic acid by the enzyme lactate dehydrogenase (LDH).
  • During anaerobic glycolysis, energy is released to allow ATP re-synthesis.
  • The net result is 2 molecules of ATP produced for one molecule of glucose broken down. (There are actually 4 moles of ATP produced but 2 are used to provide energy for glycolysis itself.)
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44
Q

Where does anaerobic glycolysis take place?

A

In the sarcoplasm of the muscle cell where oxygen isn’t available.

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45
Q

How much energy is produced by the ATP-PC system?

A

One molecule of ATP can be re-synthesised for every mole of PC.

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46
Q

How much energy is produced by the short-term lactate anaerobic system (lactic acid system)?

A

2 molecules of ATP produced for one molecule of glucose broken down. (There are actually 4 moles of ATP produced but 2 are used to provide energy for glycolysis itself.)

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47
Q

What are the advantages of the anaerobic glycolytic system?

A
  • ATP can be re-synthesised quite quickly due to very few chemical reactions and lasts for longer than the ATP-PC system.
  • In the presence of oxygen, lactic acid can be converted back into liver glycogen or used as a fuel through oxidation into carbon dioxide and water.
  • It can be used for a sprint finish (i.e. to produce an extra burst of energy).
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48
Q

What are the disadvantages of the anaerobic glycolytic system?

A
  • Lactic acid as the by-product! The accumulation of acid in the body denatures enzymes and prevents them increasing the rate at which chemical reactions take place.
  • Only a small amount of energy can be released from glycogen under anaerobic conditions (5% as opposed to 95% under aerobic conditions).
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49
Q

What is the energy continuum?

A

A term which describes the type of respiration used by physical activities. Whether it is aerobic or anaerobic respiration depends on the intensity and duration of the exercise.

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50
Q

What is the ATP-PC/anaerobic glycolytic threshold?

A

The point at which the ATP-PC energy system is exhausted and the anaerobic glycolytic system takes over.

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51
Q

What is energy supplied by when the duration of the performance is less than 10s?

A

ATP-PC

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52
Q

What is energy supplied by when the duration of the performance is 8-90s?

A

ATP-PC and anaerobic glycolytic.

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53
Q

What is energy supplied by when the duration of the performance is 90s-3mins?

A

Anaerobic glycolytic and aerobic.

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54
Q

What is energy supplied by when the duration of the performance is 3+mins?

A

Aerobic.

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55
Q

What are some examples of activities that have their energy supplied by the ATP-PC system and that last less than 10s?

A

100m, long jump, etc.

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56
Q

What are some examples of activities that have their energy supplied by the ATP-PC system and the anaerobic glycolytic system and that last 8-90s?

A

200m, 400m, gymnastic floor routine, etc.

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57
Q

What are some examples of activities that have their energy supplied by the anaerobic glycolytic system and aerobic system and that last 90s-3mins?

A

1500m, a round of boxing, etc.

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58
Q

What are some examples of activities that have their energy supplied by the aerobic system and that last 3+mins?

A

Marathon, cross country skiing, etc.

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59
Q

What type of exercise are slow twitch muscle fibres used for?

A

Low to medium intensity.

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60
Q

What do slow twitch muscle fibres use as their main method of receiving fuel?

A

Aerobic respiration.

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61
Q

What type of exercise are fast twitch muscle fibres used for?

A

High intensity.

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62
Q

What do fast twitch muscle fibres use as their main method of receiving fuel?

A

Anaerobic respiration.

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63
Q

Which type of respiration is the quickest?

A

Anaerobic.

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64
Q

Summarise ATP generation in slow twitch (type 1) muscle fibres

A
  • The main pathway for ATP production is in the aerobic system.
  • It produces the maximum amount of ATP available from each glucose molecule (up to 36 ATP).
  • Production is slow but these fibres are more endurance based so less likely to fatigue.
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65
Q

Summarise ATP generation in fast twitch (type 2x) muscle fibres

A
  • The main pathway for ATP production is via the lactate anaerobic energy system (during glycolysis).
  • ATP production in the absence of oxygen is not efficient as only 2 ATP produced per glucose molecule.
  • Production of ATP this way is fast but cannot last for long as these fibres have least resistance to muscle fatigue.
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66
Q

Why is the aerobic system the preferred energy system at low intensity/long duration exercise?

A

Because the demand for oxygen can be met and glucose can be broken down much more efficiently when oxygen is present.

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67
Q

When are fats used in energy production?

A

At low intensity, but as intensity increases, their usage becomes limited because they require more oxygen than glucose in their breakdown. As soon as oxygen supplies become limited, fat use for energy drops.

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68
Q

What is oxygen consumption?

A

The amount of oxygen we use to produce ATP.

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69
Q

What is VO2 max?

A

The maximum volume of oxygen that can be taken up by the muscles per minute.

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70
Q

What is sub-maximal oxygen deficit?

A

When there is not enough oxygen available at the start of exercise to provide all the energy (ATP) aerobically.

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71
Q

At what rate do we consume oxygen at rest?

A

Approx 0.3 to 0.4 litres per min.

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72
Q

What happens to oxygen consumption at the start of exercise?

A

It increases.

73
Q

Why does oxygen consumption increase at the start of exercise?

A

Because we use more oxygen to provide more ATP.

74
Q

What happens to oxygen consumption as the intensity of exercise increases?

A

It increases until a performer reaches sub-maximal oxygen consumption which can be 3-6 litres per min.

75
Q

At what value is sub-maximal oxygen consumption?

A

3-6 litres per min.

76
Q

What is an average VO2 max value?

A

3-6 litres per min.

77
Q

When we start to exercise, why is not all of our energy provided aerobically?

A

Because insufficient oxygen is distributed to the tissues as it takes time for the circulatory system to respond to the increase in demand for oxygen and it also takes time for the mitochondria to adjust to the rate to aerobic respiration needed. As a result, energy is provided anaerobically to satisfy the increase in demand for energy until the circulatory system and mitochondria can cope.

78
Q

What does maximum oxygen deficit give an indication for?

A

Anaerobic capacity.

79
Q

What is maximum oxygen deficit usually referred to as?

A

Maximal accumulated oxygen deficit or MAOD.

80
Q

What is EPOC?

A

The amount of oxygen consumed during recovery above that which would have been consumed at rest during the same time.

81
Q

What does EPOC stand for?

A

Excess post-exercise oxygen consumption.

82
Q

What are the 2 main components of EPOC?

A

Fast EPOC and slow EPOC.

83
Q

Why do we experience EPOC?

A

Because when we finish exercise, oxygen consumption still remains quite high in comparison with oxygen consumption at rest because extra oxygen needs to be taken in and used to try to help the performer recover.

It is the breathlessness at the end of exercise.

84
Q

What is the fast component of EPOC?

A

The restoration of ATP and phosphocreatine stores and the re-saturation of myoglobin with oxygen.

85
Q

How long does restoration of phosphocreatine take in the fast component of EPOC?

A

3mins for 100%.

30s for 50%.

86
Q

Approximately how many litres of oxygen are consumed in the 30s it takes for 50% of the PC stores to be replenished in the fast component of EPOC?

A

3 litres.

87
Q

What are the oxygen stores like in the myoglobin after exercise and what does this mean happens?

A

They are limited so the surplus of oxygen supplied through EPOC helps to replenish these stores, taking up to 2 mins and using approximately 0.5 litres of oxygen.

88
Q

Approximately how long does it take for EPOC to replenish the oxygen stores in the myoglobin?

A

2mins.

89
Q

Approximately how many litres of oxygen are used to replenish the oxygen stores in the myoglobin in 2 mins?

A

0.5 litres.

90
Q

What is the slow component of EPOC?

A

The removal of lactic acid, maintaining breathing rate and heart rate, glycogen replenishment and increase in body temperature.

91
Q

How can lactic acid be removed in the slow component of EPOC?

A

It can be converted back into pyvurate (if oxygen is present) and oxidised into carbon dioxide and water in the inactive muscles and organs. This can then be used by the muscles as an energy source.

Transported in the blood to the liver where it is converted to blood glucose and glycogen (the Cori cycle).

Converted into protein.

Removed in sweat and urine.

92
Q

What is the Cori cycle?

A

The process where lactic acid is transported in the blood to the liver where it is converted to blood glucose and glycogen.

93
Q

What can accelerate the removal of lactic acid?

A

A cool down.

94
Q

How does a cool down help to accelerate lactate removal in the slow component of EPOC?

A

The majority of lactic acid can be oxidised in mitochondria. This means a cool down can help because exercise keeps the metabolic rate of muscles high and keeps capillaries dilated meaning oxygen can be flushed through, removing the accumulated lactic acid.

95
Q

When does the slow replenishment stage of recovery begin and when does it end?

A

As soon as lactic acid appears in the muscle cell, and will continue using breathed oxygen until recovery is complete.

96
Q

How much oxygen can the slow component of EPOC take up in the first half hour of recovery and how much lactic acid can this remove?

A

Up to 5-6 litres of oxygen removing up to 50% of the lactic acid.

97
Q

Why is it important that there is maintenance of breathing and heart rates during the slow component of EPOC?

A

Because it requires extra oxygen to provide energy needed for the respiratory and heart muscles and this assists recovery as the extra oxygen is used to replenish ATP and PC stores, re-saturate the myoglobin and remove lactic acid, therefore returning the body back to its pre-exercise state.

98
Q

Why is glycogen replenishment in the slow component of EPOC important?

A

GLycogen is the main energy provider and as it is the fuel for both the aerobic and lactic acid system, it will be depleted during exercise.

99
Q

What does the replacement of glycogen stores after exercise depend on?

A

The type of exercise undertaken and when and how much carbohydrate is consumed following exercise.

100
Q

How long can the replenishment of glycogen stores take after exercise in the slow component of EPOC?

A

Several days after a marathon but in less than an hour after high duration, short intensity exercise, a significant amount of glycogen can be restored as lactic acid and is converted back to blood glucose and glycogen in the liver via the Cori cycle.

101
Q

What will accelerate glycogen restoration after exercise?

A

Eating a high carbohydrate meal within one hour.

102
Q

What are the 2 nutritional windows for optimal recovery after exercise?

A

The first 30 mins where both carbohydrates and proteins should be consumed in a 3:1 or 4:1 ratio. The combination of carbohydrate and protein helps the body to re-synthesise muscle glycogen much more efficiently than just consuming carbohydrates on their own. Many elite athletes drink chocolate milk to do this.

The second nutritional window is 1-3 hours after exercise and a meal high in protein, carbohydrate and healthy fat should be consumed.

103
Q

Why is it important to have an increase in body temperature during the slow component of EPOC?

A

When temperature remains high, respiratory rates will also remain high and this will help the performer take in more oxygen during recovery. However, extra oxygen (from the slow component of EPOC) is needed to fuel this increase in temperature until the body returns to normal.

104
Q

What energy system is used during short duratio/high intensity exercise?

A

The ATP-PC system and lactic acid.

105
Q

How does lactic acid become lactate?

A

The lactic acid quickly breaks down releasing hydrogen ions (H+). The remaining compound then combines with sodium ions (Na+) or potassium ions (K+) to form the salt lactate.

106
Q

What is the lactate threshold?

A

The point during exercise at which lactic acid quickly accumulates in the blood.

107
Q

At what point is the lactate threshold reached?

A

When there is an increase of 2 millimoles per litre of blood above resting levels of lactic acid.

108
Q

What does OBLA stand for?

A

Onset blood lactate accumulation.

109
Q

What is OBLA?

A

The point when lactate levels go above 4 millimoles per litre.

110
Q

At rest, approximately how much lactate can be found in the blood?

A

1-2 millimoles per litre of blood.

111
Q

At what point does OBLA occur?

A

When the concentration of lactate is around 4mmol per litre.

112
Q

What does measuring OBLA give an indication of?

A

Endurance capacity.

113
Q

What is lactate threshold expressed as?

A

A percentage of VO2 max.

114
Q

At what % of VO2 max is an average performers lactate threshold?

A

50%-60%.

115
Q

At what % of VO2 max is an elite performers lactate threshold?

A

70, 80 or even 90%.

116
Q

How is VO2 max determined?

A

Mainly genetically - training has little impact.

117
Q

What are the factors that affect the rate of lactate accumulation?

A 
Exercise intensity.
Muscle fibre type.
Rate of blood lactate removal.
The respiratory exchange ratio.
Fitness of the performer.
118
Q

How does exercise intensity affect the rate of lactate accumulation?

A

The higher the intensity, the greater the demand for energy (ATP) and the faster OBLA occurs.

Fast twitch fibres are used at high intensity and can only maintain their workload with the use of glycogen as a fuel. When glycogen is broken down when there is no oxygen into pyruvic acid, lactic acid is formed.

119
Q

How does muscle fibre type affect the rate of lactate accumulation?

A

Slow twitch fibres produce less lactate than fast twitch fibres. When slow twitch fibres use glycogen as a fuel, due to the presence of oxygen, the glycogen can be broken down more effectively and with little lactate production.

120
Q

How does rate of blood lactate removal affect the rate of lactate accumulation?

A

If the rate of lactate removal is equal to the rate of lactate production, then the concentration of blood lactate remains constant. If lactate production increases, then lactate will start to accumulate in the blood until OBLA is reached.

121
Q

How does the respiratory exchange ratio affect the rate of lactate accumulation?

A

It is the ratio of carbon dioxide produced compared to oxygen consumed. As this ratio has a value close to 1:0, glycogen becomes the preferred fuel and there is a greater chance of the accumulation of lactate.

122
Q

How does fitness of the performer affect the rate of lactate accumulation?

A

A person who trains regularly will be in a better position to delay OBLA as adaptations occur to trained muscles. Increased numbers of mitochondria and myoglobin, together with an increase in capillary density, improve the capacity for aerobic respiration and therefore avoid the use of the lactate anaerobic system.

123
Q

Who will have much better anaerobic endurance, an elite sprinter or a non-elite sprinter and why?

A

Elite sprinters because their body has adapted to cope with higher levels of lactate. Also, through the buffering process, they’ll be able to increase the rate of lactate removal and so have lower lactate levels.

124
Q

Why is lactate buffering good?

A

Because it means athletes will be able to work at higher intensities for longer before fatigue sets in. As well as being able to tolerate higher levels of lactate, the trained status of their working muscles will lead to adaptive responses. There will be a greater number and size of mitochondria and the associated oxidative enzymes, increased capillary density and more myoglobin.

125
Q

What is buffering?

A

A process which aids the removal of lactate and maintains acidity levels in the blood and muscle.

126
Q

What are the factors affecting VO2 max?

A 
Training
Physiological
Lifestyle
Body composition
Gender
Differences in age
Genetics
127
Q

How can training affect VO2 max?

A

VO2 max can be improved by up to 10-20% following a period of aerobic training (continuous, fartlek and aerobic interval).

128
Q

How can physiological factors affect VO2 max?

A
  • Increased max cardiac output.
  • Increased SV/ejection fraction/cardiac hypertrophy.
  • Greater HRR.
  • Increased levels of Hb and RBC count.
  • Increased stores of glycogen and triglycerides.
  • Increased myoglobin content.
  • Increased capillarisation around the muscles.
  • Increased number and size of mitochondria.
  • Increased SA of alveoli.
  • Increased lactate tolerance.
  • Less oxygen being used for heart muscle so more available to the muscles.
129
Q

How can lifestyle affect VO2 max?

A

Smoking, sedentary lifestyle, poor diet and poor fitness can all reduce VO2 max values.

130
Q

How can body composition affect VO2 max?

A

A higher percentage of body fat decreases VO2 max.

131
Q

How can gender affect VO2 max?

A

Men generally have approx. 20% higher VO2 max than women.

132
Q

How can differences in age affect VO2 max?

A

As we get older our VO2 max declines as our body systems become less efficient.

133
Q

How can genetics affect VO2 max?

A

Inherited factors of physiology limit possible improvement.

134
Q

Why is measuring energy expenditure useful?

A

As it gives an indication of the intensity of the exercise being performed and can be used to identify levels of fitness. It will also highlight the dietary requirements needed for a performer to recover and replace the energy they have used, as well as providing feedback on the effectiveness of a training programme.

135
Q

What measurements can be used to gauge energy expenditure?

A

Indirect calorimetry.
Lactate sampling.
VO2 max test.
Respiratory exchange ratio (RER).

136
Q

What is calorimetry?

A

The calculation of heat in physical changes and chemical reactions.

137
Q

What does indirect calorimetry do?

A

Measures the production of CO2 and/or the consumption of O2.

138
Q

When can indirect calorimetry be measured?

A

At rest or in aerobic exercise.

139
Q

What does calculating gas volumes in indirect calorimetry allow us to do apart from just measuring energy expenditure?

A

Find out the main substrate being used (fat or carbohydrate).

140
Q

How accurate is indirect calorimetry and why?

A

The accuracy is very reliable as it give a precise calculation of VO2 (oxygen consumption) and VO2 max.

141
Q

Why is lactate sampling used amongst elite performers?

A

To monitor training and predict performance. It can also be used to measure exercise intensity. It allows the performer to select relevant training zones either in HR or power (watts) in order to get the desidered training effect.

Regular lactate testing provides a comparison so the coach and the performer can see whether improvement has occurred.

142
Q

What is lactate sampling?

A

Involves taking a tiny blood sample and a handheld device analyses the blood and indicates how much lactate is present.

143
Q

What could you say has happened if a performer uses a lactate sampling test and it shows a lower lactate level at the same intensity of exercise?

A

The performer has an increase in peak speed/power, increased time to exhaustion, improved recovery heart rate and finally a higher lactate threshold.

144
Q

When can lactate sampling be used?

A

Any time in training.

145
Q

What is direct gas analysis?

A

Measures the concentration of oxygen that is inspired and the concentration of carbon dioxide that is expired.

146
Q

What is a cycle ergometer?

A

A stationary bike that measures how much work is being performed.

147
Q

How can VO2 max be measured?

A

Simple testing such as the multi-stage fitness test, the Harvard step test or Cooper’s 12 minute run but these only give an indication or prediction of VO2 max.

Sports labs use direct gas analysis to get much more valid and reliable results.

148
Q

Explain how VO2 max is measured in a lab

A

Involves increasing intensities on a treadmill, cycle ergometer or rowing machine.

Using a treadmill - a performer runs on a treadmill until exhaustion while the air that is expired is calculated by computer software. The volume and concentration of oxygen in the expired air is then measured and compared with the percentage of oxygen that is in atmospheric air to see how much oxygen has been used during the task.

149
Q

What is the respiratory exchange ratio (RER)?

A

The ratio of CO2 produced compared to O2 consumed.

150
Q

What is the respiratory exchange ratio (RER) used as a measure of?

A

Exercise intensity.

151
Q

Apart from exercise intensity, what does the respiratory exchange ratio (RER) provide information about?

A

Fuel usage during exercise.

152
Q

The RER ratio is calculated using what equation?

A

CO2 expired per min (VCO2) / O2 consumed per min (VO2)

153
Q

What does an RER value close to 1 suggest?

A

A performer uses carbohydrates as fuel.

154
Q

What does an RER value of approx. 0.7 suggest?

A

A performer uses fats as fuel.

155
Q

What does an RER value greater than 1 suggest?

A

Anaerobic respiration so more CO2 being produced than O2 consumed.

156
Q

What does measuring the respiratory exchange ratio require and athlete to do?

A

Requires them to be attached to a gas analyser while on a treadmill or cycle ergometer so that accurate readings can be taken on the amount of carbon dioxide produced compared to oxygen consumed.

157
Q

What is altitude training?

A

A specialist training method usually done at 2500m+ above sea level for several weeks where the partial pressure of oxygen is lower.

158
Q

What are the specialist training methods?

A

Altitude training, SAQ training, HIIT, Plyometrics.

159
Q

Why is altitude training used by athletes/what happens at altitude?

A

The partial pressure of oxygen drops as altitude increases therefore there is a huger reduction in the diffusion gradient of oxygen between the air in the lungs and between the alveoli and blood. This means that not as much oxygen diffuses into the blood so Hb is not fully saturated with O2 which results in the lower O2 carrying capacity of the blood. As less O2 is delivered to the working muscles, there is a reduction in aerobic performance and VO2 max and quicker onset of anaerobic respiration.

160
Q

What are the advantages of altitude training?

A
  • Acclimatises players to the lower level of oxygen available in the atmosphere.
  • Increased O2 carrying capacity.
161
Q

What are the disadvantages of altitude training?

A
  • Very difficult to train at the same intensity due to the reduction in the partial pressure of oxygen so there can be a loss of fitness or detraining.
  • Altitude sickness can have a detrimental effect on a training programme.
  • The benefits gained can be lost very quickly on return to sea level and the body can only produce a limited amount of EPO.
  • Living away from home can also result in psychological problems such as homesickness.
162
Q

What time of training can interval/HIIT training be used for?

A

Both aerobic and anaerobic.

163
Q

What is interval training?

A

A form of training in which periods of work are interspersed with recovery periods.

164
Q

What four main variables are used to ensure the interval training is specific?

A
  • The duration of the work interval.
  • The intensity or speed of the work interval.
  • The duration of the recovery interval.
  • The number of work intervals and recovery intervals.
165
Q

What is HIIT?

A

Involves short intervals of maximum intensity followed by a recovery interval of low to moderate intensity exercise.

166
Q

What does HIIT improve?

A

Fat burning potential, glucose metabolism and both aerobic and anaerobic endurance.

167
Q

What do the many variations of HITT involve?

A
  • Different numbers of high intensity work intervals and low intensity recovery intervals.
  • Different lengths of time for the work and recovery intervals.
  • Different exercise intensity for the recovery interval (low or medium intensity).
168
Q

What are plyometrics?

A

Involves repeated rapid stretching and contracting of muscles to increase muscle power.

169
Q

What movements does plyometrics involve?

A

Hopping, bounding, depth jumping and medicind ball work.

170
Q

What muscle fibres does plyometrics use?

A

Fast twitch muscle fibres.

171
Q

What is the stretch shortening cycle?

A

3 phases:

  1. Eccentric phase or pre-loading/pre-stretching phase. On landing, the muscle performs an eccentric contraction where it lengthens under tension.
  2. Amortisation phase is next and is the time between the eccentric and concentric muscle contractions. This needs to be as short as possible so the energy stored from the eccentric contraction is not lost.
  3. Concentric or muscle contraction phase uses the stored energy to increase the force of the contraction (more stretch = more force).
172
Q

What is speed?

A

How fast a person can move over a specified distance or how quickly a body part can be put into action.

173
Q

In what sports is SAQ the most important?

A

Games players.

174
Q

What does SAQ stand for?

A

Speed, agility, quickness.

175
Q

What is agility?

A

The ability to move and position the body quickly and effectively while under control.

176
Q

What does good agility require?

A

A combination of speed, co-ordination, balance and flexibility.

177
Q

What is SAQ training?

A

A type of training that aims to improve multi-directional movement through developing the neuromuscular system.

178
Q

How is energy provided in SAQ training?

A

Anaerobically because it uses activities performed with maximum force at high speed.

A-level PE (16 decks)

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