5.3-5 Energy transfer, VO2 Max Flashcards
what is the lactate threshold
the point during exercise at which lactic acid quickly accumulates in the blood
what is OBLA (Onset of Blood Lactate Accumulation)
the point when lactate levels gove above 4 millimoles per litre
what is buffering
a process which aids the removal of lactate and maintains acidity levels in the blood and muscles
what is VO2 max
the maximum volume of oxygen that can be taken up by the muscles per minute
what is EPOC
the amount of oxygen consumed during recovery above that which would have been consumed at rest during the same time
what is the fast component of EPOC
the restoration of ATP and PC stores and the re saturation of myoglobin with oxygen
what is the criteria for OBLA to occur
85% of HRmax
75% of VO2 max
4mM of lactate accumulation
what are the different types of threshold
lactate threshold = aerobic
VO2 max = anaerobic
OBLA = anaerobic
what are factors that will affect the rate of lactate accumulation
- intensity of exercise
- fitness of performer
- VO2 max of performer
- performers OBLA
how does the intensity of exercise affect the rate of lactate accumulation
lactic acid will be present at submaximal exercise and as intensity increases lactic acid will not be able to be broken down so accumulation will increase
how does the fitness of a performer affect lactate accumulation
decrease lactate accumulation as you increase fitness as ability to clear lactate from your body increases as it becomes more adapted
how does the VO2 max of a performer affect lactate accumulation
higher VO2 max will decrease lactate accumulation as there is more oxygen present to aerobically respire
how does a performers OBLA affect lactate accumulation
performer can work at a higher intensity for longer until OBLA is achieved as they can delay lactate threshold
what is a buffering capacity
the ability of hydrogen carbonate ions to neutralise the effects of lactic acid
what is maximal oxygen deficit
when a performer lacks oxygen due to the intensity of the activity and anaerobic respiration occurs
what is submaximal oxygen deficit
when a performer lacks oxygen after exercising aerobically for a long period of time
what are the factors affecting VO2 max
- physiological
- training
- lifestyle
- body composition
- gender
- differences in age
- genetics
how does physiology affect VO2 max
- increased max CO/SV
- increased levels of haemoglobin and RBC
- increased myoglobin
- increased number and size of mitochondria
- increased SA of of alveoli
how does lifestyle affect VO2 max
smoking, sedentary lifestyle and poor diet will reduce VO2 max values
how does body composition affect VO2 max
higher percentage of body fat will decrease VO2 max
how does gender affect VO2 max
men have a 20% approx. higher VO2 max than women due to more muscle fibres
how does age affect VO2 max
as we get older VO2 max will decrease as our body becomes less efficient
how does genetics affect VO2 max
inherited physiological factors limit improvement
how does training affect VO2 max
aerobic training can improve VO2 max by 10-20%
what occurs during the fast component of EPOC (alactic)
- re saturation of myoglobin with oxygen
- resynthesis of ATP
- resynthesis of PC (50% takes 30s to resynthesise, 100% takes 2-mins)
what occurs during the slow component of EPOC (lactacyd)
- removal of lactic acid into lactate and h+ ions
- lactate is converted into urea, H2O and CO2 or glucose then glycogen (cori cycle in the liver)
- takes 5min-1h
what is the cori cycle
the process where lactic acid is transported in the blood to the liver where it is converted to blood glucose and glycogen
