Lecture 19 - Integration I Flashcards
What is the most common measure for cardiorespiratory fitness?
VO2max
What is VO2max?
VO2max is a measure of the maximal rate of O2 consumption per minute.
Until what point does oxygen uptake increase linearly to speed?
VO2max
What is the VO2max in trained individuals compared to untrained?
VO2max found at higher speed and oxygen uptake
What sports increase VO2max?
Sports that require more endurance (that is length of continual exercise)
How can VO2max drop?
Age
What are factors that effect VO2max?
Genetics
- initial value
- how much it can change
Sex (male higher than female)
Training
What are the 4 major adaptions that can improve VO2max?
Respiratory pulmonary diffusion
Maximal cardiac output (amount of blood leaving heart)
Muscle capacity to extract O2 from circulating RBCs
Blood’s capacity to transport O2
At rest, what % of oxygen do muscle fibres extract?
60%
What is the haematocrit?
Haematocrit is % of blood made up of cells of which 99% are RBCs.
Haematocrit is 41-50% in adult males, and 36-46% in adult women.
What is the avg haemoglobin (Hg) in whole blood?
15g Hg per 100 ml of whole blood
How much oxygen can 1g of Hg bind?
1.33 ml of oxygen
How can athletes increase RBCs in blood?
Training at high altitude
Blood doping (donor blood or EPO)
Where is EPO produced?
In kidney
What does EPO do?
Enter bone marrow to stimulate RBC production - increase RBC production which increases oxygen capacity
How does O2 move into muscle cells?
O2 gradient
O2 moves from the high concentration in blood and to a low concentration in the muscle cells.
What establishes the O2 gradient between blood and muscle cells?
The O2 gradient is generated by the oxidation of O2 in muscle cells by the energy-generating mitochondria.
What happens when there is an increase in mitochondria in muscles? relating to O2
The more mitochondria in the muscles, the more O2 can be used and therefore more O2 the muscles can extract because of a greater diffusion gradient.
How can mitochondria be increased?
With training
What is the crossover concept- carbohydrates vs fats?
At rest and low to moderate intensities (below 60% of maximal oxygen uptake), lipids serve as the main substrate for generating ATP. During high-intensity exercise (>75% of maximal oxygen
uptake) a shift to CHO.
What will training do to crossover point?
Training will shift the crossover point towards higher exercise intensities.
What are the important fuel sources of ATP generation?
Fat and CHOs are important fuel sources for ATP generation by mitochondria.
What is needed for the oxidation of fats and CHOs?
Oxygen
