Adaptations to Prolonged Exercise

Question 1

According to Bouchard et al 1999 what percentage of VO2max is due to heritability (and how much is specifically maternal heritability?)

Answer 1

47% Heritable. 28% Maternal Heritability

Question 2

What is the primary adaptation to endurance training?

Answer 2

Increase in VO2max

Question 3

Why is VO2max more heritable from the mother than the father?

Answer 3

You inherit your mitochondria from your mother

Question 4

What is the ‘Oxygen Deficit’ when exercise intensity increases?

Answer 4

When intensity increseases, oxygen demand increases immediately, but oxygen uptake increases gradually. Difference between these is the oxygen deficit

Question 5

How do you calculate VO2 gain?

Answer 5

Change in oxygen uptake/change in resistance or work

Question 6

What is the ‘time constant’ of the VO2 response?

Answer 6

1/4 of how long it takes to reach steady state. Divide time taken by 4.

Question 7

What is the implication of having greater VO2 gain? (Burnley and Jones 2007)

Answer 7

Smaller time constant, so smaller oxygen debt, so sparing glycogen stores, phosphocreatine stores, and reducing the increase in metabolites associated with fatigue from glycolysis

Question 8

What did Koppo et al 2004 find about differences in time constants between trained and untrained individuals at various intensities?

Answer 8

Untrained people have significantly higher time constant at all intensities. At lactate threshold, untrained have double the time constant of trained.

Question 9

What specific situation can exercise affect the lungs to improve endurance performance? Give reference

Answer 9

Swimming can increase lung capacity (Clanton et al 1987)

Question 10

What is the main measure of respiratory muscle strength?

Answer 10

Maximal inspiratory/expiratory mouth pressure (MIP/MEP)

Question 11

What are the measures of measuring respiratory muscle endurance?

Answer 11

• Maximum voluntary ventilation (MVV)
• Maximum sustainable ventilatory capacity (MSV)
• Maximum sustainable inspiritory pressuer
• Incremental pressure threshold loading
• Breathing endurance against fixed load

Question 12

What effect does running have on respiratory muscle strength and endurance? give reference

Answer 12

Significant increase in RM endurance, no significant change in RM strength (Robinson and Kjeldgaard 1982)

Question 13

What effect does swimming have on respiratory muscle strength and endurance?

Answer 13

Significant increase in both RM strength and endurance (Clanton et al 1987)

Question 14

In what ways can training affect haemoglobin to increase endurance performance?

Answer 14

• Very little change in haemoglobin concentration
• No change to percent saturation
• Increase in total haemoglobin mass

Question 15

What can explain the increase in total haemoglobin mass from training, when haemoglobin concentration does not change?

Answer 15

More blood.

Question 16

Why do trained athletes have a lower heart rate at any given intensity than an untrained athlete, but a higher oxygen uptake? Reference

Answer 16

Higher stroke volume (Saltin 1969)

Question 17

Apart from cardiac hypertrophy, what explains the higher stroke volume in athletes?

Answer 17

Increased preload (filling of the heart) due to plasma volume expansion from training (up to 500ml of plasma volume gain within first week of training)

Question 18

Summarise the adaptations to oxygen delivery due to endurance exercise

Answer 18

• Little adaptation in lungs
• Increased maximal cardiac output
• Increased total haemoglobin

Question 19

What is angiogenesis?

Answer 19

Growth of new blood vessels

Question 20

What is angiogenesis intussusception?

Answer 20

Splitting of blood vessel into two separate new blood vessels

Question 21

What is angiogenesis ‘sprouting’?

Answer 21

When a new blood vessel shunts out of the side of an existing blood vessel

Question 22

According to Prior et al 2004, what is the difference in capillary density between trained and untrained individuals?

Answer 22

Trained individuals have 2-3 times more capillaries per muscle fibre

Question 23

what impact does endurance have on mitchondria?

Answer 23

Increases the size and number/density of mitochondria

Question 24

What is one measure commonly used to estimate the change in size/number of mitochondria?

Answer 24

Increase in oxidative enzymes e.g. citrate synthase and succinate dehydrogenase, as they increase in parallel with mitochondria with response to exercise

Question 25

What are the main consequences of mitochondrial adaptation?

Answer 25

• Increases fat metabolism (because mitochondria are necessary for fat oxidation) so less glycogen depletion
• Greater sensitivity to changes in ADP, meaning quicker VO2 response to increased workload

Question 26

What is a secondary consequence of mitochondria increasing fat metabolism, and so less glycogen depletion

Answer 26

Decreased rate of glycolysis means decreased lactate accumulation so less fatigue and HIGHER LACTATE THRESHOLD