Adaptations to endurance exercise

Question 1

How much are changes to VO2 max attributed to genetic factors?
How much is maternal heritability and why?

Answer 1

~47%

~28% due to maternal heritability as we inherit our mitochondria from our mother
- (Bouchard et al, 1999)

Question 2

Define O2 deficit

Answer 2

the difference between O2 requirement and O2 uptake at the onset of exercise.
- (Burnley & Jones, 2007)

Question 3

Why does an O2 deficit occur?

Answer 3

Upon beginning of exercise, your body requires a set amount of oxygen. Your body can’t keep up with the demands straight away and gradually increases O2 uptake.

Question 4

What is the time constant of the VO2 response?

Answer 4

1/4 of the time taken to reach steady state of oxygen uptake

Question 5

What are the implications of a reduced time constant of VO2 response?

Answer 5

less O2 deficit, therefore…

less reliance on anaerobic energy systems, therefore…

> less PCr depletion
less glycogen depletion
blunt the increase in metabolites associated with fatigue

• (Burnley & Jones, 2007)

Question 6

What determines VO2 kinetics?

Answer 6

training status

trained cyclists reach steady state quicker (reduced time constant) than untrained cyclists in multiple power output conditions
- (Koppo et al, 2004)

Question 7

What effect does endurance exercise have on…

1. time constant of VO2 response
2. O2 deficit
3. VO2 max

Answer 7

1. reduces
2. reduces
3. improves

Question 8

What 2 processes can the physiological adaptations associated with endurance exercise be split in to?

Answer 8

1. O2 delivery (central aspects)

2. O2 delivery (peripheral aspects)

Question 9

Do the lungs adapt to (get larger from) running or rowing?

Answer 9

no,

large lung capacities in these sports are seen likely as a result of genetic endowment

Question 10

do the lungs adapt to (get larger from) swimming?

Answer 10

you bet your ass they do,

a progressive swimming programme for competitive female college swimmers over 10 weeks was shown to…
>increase vital capacity
>increase total lung capacity
- (Clanton et al, 1987)

Question 11

What effect does running training have on respiratory muscles?

Answer 11

. no change to maximum inspiratory pressure (strength)
. 16% increase to maximum sustainable ventilatory capacity (endurance)
- (Robinson & Kjeldgaard, 1982)

Question 12

What effect does swimming training have on respiratory muscles?

Answer 12

. 17% increase to maximum inspiratory pressure (strength)
. 113% increase to time @ 65% MIP (endurance)
- (Clanton et al, 1987)

Question 13

Are we able to effectively compare the effects of running and swimming training on inspiratory muscle endurance from the studies of Robinson & Kjeldgaard,
(1982) and Clanton et al (1987) ?

Answer 13

No,

they used different measures to assess inspiratory muscle endurance

Question 14

True or false…

haemoglobin saturation and concentration (per L of blood) significantly increase with endurance training

Answer 14

False,
no changes to saturation
only slight increase in concentration

Question 15

What is the effect of endurance training on total haemoglobin mass and why does this change occur?

Answer 15

Total haemoglobin mass increases, due to rises in blood volume with endurance training.

Question 16

What effect does endurance training have on heart rate at any given intensity (O2 uptake)?

Answer 16

HR is lower is at any given O2 uptake

- (Saltin, 1969)

Question 17

Does Stroke volume change with endurance training?

Answer 17

yes,
increases for any given oxygen uptake
- (Saltin, 1969)

Question 18

What causes the increase to cardiac output with training?

Answer 18

Increases to SV, as HR drops

Question 19

What causes the increase in stroke volume with endurance exercise?

Answer 19

> increased blood plasma volume (short term)

> cardiac hypertrophy (long term)

Question 20

What effect does increasing plasma volume by 200-300 mL via infusion have on VO2 max?

Answer 20

5percenters

Increases it by roughly 5%

Question 21

What is the overall effect of all of these adaptations to O2 delivery?

Answer 21

Increased maximal delivery of O2 to periphery

Question 22

What effect does training have on capillary density, and by what process do these changes occur?

Answer 22

training = increased capillary density (2-3 x more capillaries per muscle fibre)
occurs due to angiogenesis which takes one of two forms…
> sprouting - new vessel sprouts from another
> intussusception - one vessel split in two

• (Prior et al, 2004)

Question 23

True or false…

endurance training increases the size AND number of mitochondria

Answer 23

True

Question 24

How is citrate synthase activity influenced by activity?

Answer 24

it is proportional to the number of muscle contraction an individual makes.
Immobilised (x0.7)
moderate training (x1.5)
elite training (x3)

Question 25

What are 3 consequences of the mitochondrial adaptations as a response to endurance exercise?

Answer 25

1. mitochondria are closer to intramuscular triglycerides (more CSA touching)
   as a result…
2. increased fat metabolism during exercise
   as a result…
3. less depletion of glycogen stores during activity

Question 26

What effect does training have on the formation of lactate?

Answer 26

increased mitochondria = decreased accumulation of pyruvate

Question 27

What effect does training have on the removal of lactate?

Answer 27

better maintenance of blood flow to the kidneys and liver = greater removal of lactate

Question 28

What effect does a higher lactate threshold have on endurance performance?

Answer 28

you’re able to work for longer at a higher percentage of VO2 max

Question 29

What is a-vO2 diff?

Answer 29

arteriovenous O2 difference
the difference in O2 content of the arterial and venous blood.

gives an indication of much much oxygen is removed from the blood as it circulates through the body

Question 30

What is the effect of detraining on VO2 max?

Answer 30

rapid decline, mainly due to decreases in stroke volume

- (Coyle et al, 1984)

Question 31

What is the effect of detraining on a-vO2 diff?

Answer 31

little change after 3 weeks, then gradual decline.

- (Coyle et al, 1984)

Question 32

How do the adaptations to the mitochondria respond to detraining?

Answer 32

rapid decline
after 1 week off training, 50% of the gains from 6 weeks of training were lost. It took roughly 4 weeks to regain back what was lost in 1 week of detraining.

Question 33

What are the early increases in maximal oxygen uptake with training primarily down to?

Answer 33

increases in maximal cardiac output (increased stroke volume)

Question 34

Why may an untrained individual gain weight at the beginning of an endurance training protocol?

Answer 34

Increased blood volume