Energy transfer, VO2 Max Flashcards
What is lactate threshold?
the point during exercise at which lactic acid quickly accumulates in the blood
What is OBLA?
Point when lactate levels go above 4 millimoles per litres
What is VO2 max?
the maximum volume of oxygen that can be taken up by the muscles per minute
What is sub maximal oxygen deficit?
when there is not enough oxygen available at the start of exercise to provide all the energy aerobically / when a performer lacks oxygen after exercising aerobically for a long period of time
What is maximal oxygen deficit?
when a performer lacks oxygen due to the intensity of the activity and anaerobic respiration occurs
What happens above the aerobic threshold?
energy produced by formation of lactate
crossing lactate threshold
causes exponential increase in lactate
Why can you still exercise between aerobic and anaerobic threshold?
although increase in accumulation of lactate, theres no decrease in clearance of lactate
What happens after anaerobic threshold?
drastic increase as ability to clear lactate decreases
What are the criteria for OBLA?
85% HR
75% VO2 max
What causes lactate accumulation?
higher intensity exercise causes more lactic acid produced
lactate accumulates in muscles, slowing enzyme activity, affecting break down of glycogen, causing muscle fatigue, inhibiting muscular contractions
What cause OBLA?
as intensity of exercise increases, body is unable to produce enough oxygen to break down lactate, so levels of lactate build up
What does measuring OBLA give an indication of?
endurance capacity
as fitness increases, lactate threshold becomes delayed
an elite performer has a higher lactate threshold as a percentage of VO2 max e.g. 90% of VO2 max
What factors affects lactate accumulation?
intensity of exercise
fitness of performer - body increases ability to clear lactate
VO2 Max of performer - delays lactate accumulation
Performers OBLA - can delay lactate threshold
What is buffering capacity?
the ability of hydrogen carbonate ions to neutralise the effects of lactic acid
What factors affect VO2 Max?
physiological
lifestyle
body composition
gender
age
genetics
training
What physiological factors affect VO2 Max?
Increased max cardiac output
increased stroke volume
less O2 being used by heart muscle so more available to muscles
increased levels haemoglobin/rbc
increased myoglobin, number of mitochondria, lactate tolerance
How will lifestyle affect VO2 Max?
smoking, sedentary lifestyle, poor diet, poor fitness reduce
How will body composition affect VO2 Max?
higher % body fat decreases VO2 Max
How will gender affect VO2 Max?
men have more muscle so more mitochondria for energy production/myoglobin for oxygen to bind
How will age affect VO2 Max?
VO2 max decreases with age as body systems become less efficient
How will genetics affect VO2 Max?
inherited factors of physiology
How will training affect VO2 Max?
aerobic training improves VO2 Max
