Adaptations to Prolonged Exercise Flashcards
According to Bouchard et al 1999 what percentage of VO2max is due to heritability (and how much is specifically maternal heritability?)
47% Heritable. 28% Maternal Heritability
What is the primary adaptation to endurance training?
Increase in VO2max
Why is VO2max more heritable from the mother than the father?
You inherit your mitochondria from your mother
What is the ‘Oxygen Deficit’ when exercise intensity increases?
When intensity increseases, oxygen demand increases immediately, but oxygen uptake increases gradually. Difference between these is the oxygen deficit
How do you calculate VO2 gain?
Change in oxygen uptake/change in resistance or work
What is the ‘time constant’ of the VO2 response?
1/4 of how long it takes to reach steady state. Divide time taken by 4.
What is the implication of having greater VO2 gain? (Burnley and Jones 2007)
Smaller time constant, so smaller oxygen debt, so sparing glycogen stores, phosphocreatine stores, and reducing the increase in metabolites associated with fatigue from glycolysis
What did Koppo et al 2004 find about differences in time constants between trained and untrained individuals at various intensities?
Untrained people have significantly higher time constant at all intensities. At lactate threshold, untrained have double the time constant of trained.
What specific situation can exercise affect the lungs to improve endurance performance? Give reference
Swimming can increase lung capacity (Clanton et al 1987)
What is the main measure of respiratory muscle strength?
Maximal inspiratory/expiratory mouth pressure (MIP/MEP)
What are the measures of measuring respiratory muscle endurance?
- Maximum voluntary ventilation (MVV)
- Maximum sustainable ventilatory capacity (MSV)
- Maximum sustainable inspiritory pressuer
- Incremental pressure threshold loading
- Breathing endurance against fixed load
What effect does running have on respiratory muscle strength and endurance? give reference
Significant increase in RM endurance, no significant change in RM strength (Robinson and Kjeldgaard 1982)
What effect does swimming have on respiratory muscle strength and endurance?
Significant increase in both RM strength and endurance (Clanton et al 1987)
In what ways can training affect haemoglobin to increase endurance performance?
- Very little change in haemoglobin concentration
- No change to percent saturation
- Increase in total haemoglobin mass
What can explain the increase in total haemoglobin mass from training, when haemoglobin concentration does not change?
More blood.
Why do trained athletes have a lower heart rate at any given intensity than an untrained athlete, but a higher oxygen uptake? Reference
Higher stroke volume (Saltin 1969)
Apart from cardiac hypertrophy, what explains the higher stroke volume in athletes?
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)
Summarise the adaptations to oxygen delivery due to endurance exercise
- Little adaptation in lungs
- Increased maximal cardiac output
- Increased total haemoglobin
What is angiogenesis?
Growth of new blood vessels
What is angiogenesis intussusception?
Splitting of blood vessel into two separate new blood vessels
What is angiogenesis ‘sprouting’?
When a new blood vessel shunts out of the side of an existing blood vessel
According to Prior et al 2004, what is the difference in capillary density between trained and untrained individuals?
Trained individuals have 2-3 times more capillaries per muscle fibre
what impact does endurance have on mitchondria?
Increases the size and number/density of mitochondria
What is one measure commonly used to estimate the change in size/number of mitochondria?
Increase in oxidative enzymes e.g. citrate synthase and succinate dehydrogenase, as they increase in parallel with mitochondria with response to exercise
What are the main consequences of mitochondrial adaptation?
- 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
What is a secondary consequence of mitochondria increasing fat metabolism, and so less glycogen depletion
Decreased rate of glycolysis means decreased lactate accumulation so less fatigue and HIGHER LACTATE THRESHOLD
