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A2 Epoc, OBLA, VO2
A2 AQA Epoc fatigue obla and vo2max
Question | Answer |
---|---|
Definition of VO2max? | “The maximum volume of oxygen that can be utilised or consumed by the working muscles per minute” |
What type of activity will benefit from a high VO2 max? | Endurance event |
Vo2 max dependes on two factors what are they | Effective oxygen delivery Aerobic friendly structure |
Name two tests for VO2 max? | Multi stage fitness Cooper 12 min run |
Name 3 physiological factors that contribute to a high VO2 max | High number of slow twitch fibres High capillary density High number of mitochondria High blood volume & haemoglobin content |
Factors that affect VO2 max | Age, gender,lifestyle, training,physiology, genetics, body composition |
What is OBLA | Onset of blood lactate accumulation |
At what level is OBLA said to occur? | When blood lactate levels exceed 4mmol per litre of blood |
Why does OBLA occur? | Because of an increase in exercise intensity & lactate production |
How much is the normal level of blood lactate when not exercising? | 1-2mmol per litre of blood |
OBLA is measured as a percentage of what? | VO2max |
OBLA depends on what? | Aerobic fitness of athlete a highly trained individual can work at 85% of V02 max |
How can you increase your OBLA level? | Through training relevant energy and muscle fibres and buffering |
How much can our VO2 max be improved through training? | Up to 10-20% through aerobic training |
Why does VO2 max increase through aerobic training? | Increase in max CO / increased SV, ejection fraction, cardiac hypertrophy / increased blood vol / increased myoglobin / increased no. & size of mitochondria |
How can one person be fitter than another if they have the same VO2max? | If they have a higher OBLA level i.e. 75% of Vo2 max compared to 55%. They would be able to work at a higher intensity for longer |
What does EPOC stand for? | Excess post exercise oxygen consumption |
What are the two stages? | Fast replenishment and slow replenishment |
Name three causes of fatigue during exercise? | Reduced rate of ATP resynthesis/Dehydration/Glycogen depletion/Reduced levels of calcium/accumulation of H+ions/reduced levels of acetylcholine |
What happens during the slow replenishment stage? | Removal of lactic acid / maintenance of heart rate and respiratory rate /replenishment of glycogen stores / elevated body temp |
What is an oxygen deficit? | The volume of oxygen required to complete the exercise aerobically |
How long is the fast replenishment stage? | Usually complete within 2-3 minutes |
What is recovery? | The return of the body to its pre exercise state. |
When can you recover from exercise? | The return of the body to its pre exercise state. |
How long can the slow replenishment stage last? | Up to two hours |
What happens during the fast replenishment stage? | Re-saturation of myoglobin and resynthesis of ATP PCr |
When can you recover from exercise? | When there is sufficient oxygen available |