Energy systems - recovery

Question 1

What is submaximal oxygen deficit?

Answer 1

At the start of exercise, insufficient oxygen is distributed to the tissues for all the energy to be produced aerobically.
It takes time for the body to respond to the increase in demand for oxygen.
So, energy is intially provided anaerobically to satisfy the increase in demand until the body can cope.

Question 2

What is maximal oxygen deficit?

Answer 2

Maximal Accumulated Oxygen Deficit (MAOD).
It indicates anaerobic capacity.
The oxygen deficit is bigger as the performer is more short of oxygen so they do more work anaerobically.

Question 3

What is EPOC?

Answer 3

Excess Post-exercise Oxygen Consumption.
The volume of oxygen consumed during recovery above the resting rate.
There are two components:
Fast replenishment stage and the slow replenishment stage.

Question 4

What is the fast replenishment stage?

Answer 4

It uses the extra oxygen that is taken in during recovery to restore ATP and phosphocreatine and to re-saturate myoglobin with oxygen.

Question 5

How long does restoration of phosphocreatine take?

Answer 5

Complete restoration of phosphocreatine takes up to 3 minutes, but 50% of stores can be replenished after 30 seconds, during which approximately 3 litres of oxygen are consumed.

Question 6

Why is myoglobin replenished in the fast component?

Answer 6

Myoglobin has a high affinity for oxygen.
It stores oxygen in the sarcoplasm that has diffused from the haemoglobin in the blood.
After exercise, oxygen stores in the myoglobin are limited.
The surplus of oxygen supplied through EPOC helps replenish these stores.
It takes up to 2 minutes and uses approximately 0.5L of oxygen.

Question 7

What is the slow replenishment stage?

Answer 7

Its functions involve:
Removal of lactic acid
Maintenance of breathing and heart rate
Glycogen replenishment
Increase in body temperature.

Question 8

How does a cool-down aid in lactic acid removal?

Answer 8

The majority of lactic acid can be oxidised in the mitochondria, so performing a cool-down can accelerate its removal.
Exercise keeps the metabolic rate of muscles high and keeps capillaries dilated, which means oxygen can be flushed through, removing the accumulated lactic acid.

Question 9

How does removal of lactic acid occur?

Answer 9

Oxidation into carbon dioxide and water in the inactive muscles and organs and used by the muscles as an energy store.
Transported in the blood to the liver where it is converted to blood glycogen and glucose (Cori cycle).
Converted into protein.
Removed in sweat and urine.

Question 10

How long does lactic acid removal take?

Answer 10

The slow replenishment stage occurs as soon as lactic acid occurs in the muscle cell.
This can take up to 5-6L of oxygen in the first 30mins of recovery, removing up to 50% of lactic acid.
Full recovery may take an hour or longer, depending on the intensity and duration of exercise.

Question 11

What is maintenance of breathing and heart rates?

Answer 11

Maintaining breathing and heart rate requires extra oxygen to provide the energy needed for the respiratory and heart muscles.
This assists recovery as the extra oxygen is used to replenish ATP and phosphocreatine stores, re-saturate the myoglobin and remove lactic acid.
This returns the body back to its pre-exercise state.

Question 12

When is the optimal recovery after exercise?

Answer 12

There are two nutritional windows:
The first is 30 minutes after exercise, where both carbohydrates and proteins should be consumed in a 3:1 or 4:1 ratio.
The second is 1 to 3 hours after exercise, and a meal high in protein, carbohydrate and healthy fat should be consumed.

Question 13

How long does glycogen replenishment take?

Answer 13

It may take several days to complete the restoration of glycogen after a marathon.
But in less than an hour after short-duration, high-intensity exercise a significant amount of glycogen can be restored as lactic acid is converted back to blood glucose and glycogen in the liver via the Cori cycle.

Question 14

What does the length of glycogen replenishment depend on?

Answer 14

It depends on the type of exercise undertaken and when and how much carbohydrate is consumed following exercise.
Eating a high-carbohydrate meal will accelerate glycogen restoration.

Question 15

Why is an increase in body temperature needed?

Answer 15

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 is needed to fuel this increase in temperature until the body returns to normal.

Question 16

How is energy transferred during short-duration, high-intensity exercise?

Answer 16

Energy has to be produced rapidly.
The aerobic system is too complicated to produce energy rapidly, so the body needs to rely on anaerobic respiration using the ATP-PC system and the anaerobic glycolytic.
However, these systems cannot produce energy for long periods of time, and OBLA occurs.

Question 17

Which factors affect the rate of lactate accumulation?

Answer 17

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

Question 18

How does exercise intensity affect lactate accumulation?

Answer 18

The higher the exercise intensity, the greater the demand for energy (ATP) and the faster OBLA occurs.
This is because when glycogen is broken down anaerobically into pyruvic acid, lactic acid is formed.

Question 19

How does muscle fibre type affect lactate accumulation?

Answer 19

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

Question 20

How does rate of blood lactate removal affect lactate accumulation?

Answer 20

If the rate of lactate removal is lower than the rate of lactate production, lactate will start to accumulate in the blood until OBLA is reached.

Question 21

How does the fitness of the performer affect lactate accumulation?

Answer 21

A person who trains regularly will be in a better position to delay OBLA, as adaptions occur to trained muscles.
Increased mitochondria and myoglobin content, and capillary density, improve the capacity for aerobic respiration and therefore avoid the use of the anaerobic glycolytic system.

Question 22

What is lactate accumulation?

Answer 22

The anaerobic-glycolytic system produces lactic acid as a result of glycolysis.
This lactic acid quickly breaks down, releasing hydrogen ions.
The remaining compound then combines with sodium or potassium ions to form salt lactate.
As lactate accumulates in the muscles, more hydrogen ions are present and this increases acidity.
This slows down enzyme activity and affects the breakdown of glycogen, causing muscle fatigue.

Question 23

What is lactate threshold?

Answer 23

The point at which lactic acid rapidly accumulates in the blood (increase by 2 millimoles per litre of blood above resting levels).
It is the crossing of the aerobic/anaerobic threshold.
We are constantly producing small amounts of lactate due to RBC activity when working at low intensity, but the levels are low and the body deals with these effectively.
As the intensity increases and the body is unable to produce enough oxygen to break down lactate, it accumulates - OBLA.

Question 24

What is OBLA?

Answer 24

Onset of Blood Lactate Accumulation.
The point when lactate levels go above 4 millimoles per litre.
At rest, approximately 1-2 millimoles per litre are found in the blood.
Measuring OBLA gives an indication of endurance capacity.
Some individuals can work at higher levels of intensity than others before OBLA and can delay LT.

Question 25

What are the measurements of lactate threshold?

Answer 25

It is expressed as a % of VO2 max. As fitness increases, the LT becomes delayed. Average performers have a LT of 50-60% of VO2 max. Elite performers have a LT of 70, 80 or 90% of VO2 max.

Question 26

How does training affect lactate threshold?

Answer 26

Training has a limited effect on VO2 max as it is genetically determined so the big difference in performance comes from the delayed LT. When we exercise, we tend to work just below our LT. The fitter we are, the higher our lactate threshold as a percentage of VO2 max, and hence the harder we can work.

Question 27

How does lactate-producing capacity and sprint/power performance vary?

Answer 27

Elite sprinters and power athletes will have a much better anaerobic endurance than non-elite sprinters. This is because their body has adapted to cope with higher levels of lactate. In addition, buffering will increase the rate of lactate removal and consequently will have lower lactate levels.

Question 28

What can elite performers do as well as lactate producing capacities?

Answer 28

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.

Question 29

What is buffering?

Answer 29

A process which aids the removal of lactate and maintains acidity levels in the blood and muscles. It works like a sponge soaking up the lactate. It means athletes will be able to work at higher intensities for longer before fatigue sets in.

Question 30

How is energy expenditure measured?

Answer 30

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

Question 31

What is indirect calorimetry?

Answer 31

It is a technique that provides an accurate estimate of energy expenditure through gas exchange. It measures how much carbon dioxide is produced and how much oxygen is consumed at rest and during aerobic exercise. Calculating the gas volumes also enables us to find out the main substrate being used (fat or carbohydrate). The accuracy is very reliable as it gives a precise calculation of VO2 and VO2 max.

Question 32

What is lactate sampling?

Answer 32

It is an accurate and objective measure of the level of lactate in the blood. It can also be used to measure exercise intensity, give an idea of fitness level and enable the performer to select relevant training zones. Regular testing provides a comparison to see whether improvements have occurred. Lower lactate level at the same intensity indicates increase in peak speed/power, increased time to exhaustion, improved recovery heart rate and higher lactate threshold.

Question 33

What is the VO2 max test?

Answer 33

Most commonly the multi-stage fitness test. Performs a 20m progressive shuttle run to a bleep, until they reach complete exhaustion. The Harvard step test and the Cooper 12 minute run also used, but they only give an indication or prediction of VO2 max. A lab can produce more valid and reliable results using direct gas analysis, involving increasing intensities on a treadmill, cycle ergometer or rowing machine.

Question 34

What is Respiratory Exchange Ratio?

Answer 34

The ratio of carbon dioxide produced compared to oxygen consumed. It is used as a measure of exercise intensity. It calculates energy expenditure and provides information about the use of fats and carbohydrates during exercise. It determines which energy sources are being oxidised and whether the performer is working aerobically or anaerobically.

Question 35

What do the RER values mean?

Answer 35

A RER value close to 1 = using carbohydrates. 0.7 value = performer using fats. Greater than 1 value = anaerobic respiration, so more CO2 being produced than O2 consumed.

Question 36

What is altitude training?

Answer 36

It is usually done at 2500m+ above sea level, where the partial pressure of oxygen is lower, for a minimum of 30 days.

Question 37

What is the physiology behind altitude training?

Answer 37

The low partial pressure of oxygen reduces the concentration gradient so low oxygen diffuses into the blood. The haemoglobin is not fully saturated with oxygen, resulting in low oxygen carrying capacity of the blood. EPO is triggered and begins the production of more red blood cells, meaning more haemoglobin in the blood and more oxygen can be carried. More oxygen is transported to the muscles so they can work for longer aerobically.

Question 38

What are the advantages of altitude training?

Answer 38

Increased number of red blood cells. Increased concentration of haemoglobin. Increased blood viscosity. Increased capillarisation. Increased lactate tolerance. Increases aerobic system. Benefits can last up to 14 days.

Question 39

What are the disadvantages of altitude training?

Answer 39

Altitude sickness. Expensive. Difficult to train due to lack of oxygen. Psychological problems due to being away from home. Benefits can be quickly lost on return to sea level. Only trains aerobic system. Body only produces limited EPO. Detraining as intensity has to reduce when the performer first trains due to decreased oxygen availability.

Question 40

What is High Intensity Interval Training?

Answer 40

HIIT can be used for both aerobic and anaerobic training. It involves short intervals of maximum intensity exercise followed by a recovery interval of low-moderate intensity exercise. The work interval is anaerobic and recovery is aerobic.

Question 41

What are the benefits of HIIT?

Answer 41

Pushing your body to the max during the work interval increases the amount of calories you burn. This is because it takes longer to recover from each work session. HIIT therefore improves fat burning potential, glucose metabolism and both aerobic and anaerobic endurance.

Question 42

What is plyometric training?

Answer 42

It improves speed and power. It involves high-intensity explosive activities such as hopping, bounding, depth jumping and medicine ball work using fast twitch fibres. It works on the concept that muscles can generate more force if they have previously been stretched. Training stimulates adaptations within the neuromuscular system and results in a more powerful contraction being worked.

Question 43

What is phase 1 of plyometrics?

Answer 43

The eccentric phase, on landing, the muscle performs an eccentric contraction, where it lengthens under tension.

Question 44

What is phase 2 of plyometrics?

Answer 44

The amortisation phase: The time between the eccentric and concentric muscle contraction. This time needs to be as short as possible so that the energy stored from the eccentric contraction is not lost. When an eccentric contraction occurs, a lot of the energy required to lengthen the muscle is lost as heat, but some can be stored and is available for the concentric contraction.

Question 45

What is phase 3 of plyometrics?

Answer 45

The concentric or muscle contraction phase which uses the stored energy to increase the force of contraction.

Question 46

What is Speed, Agility, Quickness in SAQ?

Answer 46

Speed refers to how fast a person can move over a specified distance or how quickly a body part can be put into motion. Agility is the ability to move and position the body quickly and effectively while under control.