Transcript A2 Physical Education The Recovery process Oxygen debt & deficit

A2 Physical
Education
The Recovery process
Oxygen debt & deficit
O2 requirement
O2 deficit
Oxygen
consumption
Steady state
O2consumption
EPOC/Oxygen debt
Resting O2
consumption
Start
Exercise
End
Exercise
End
Recovery
Oxygen debt & deficit
 HR does not immediately return to its normal resting
value.
 It is elevated to help the body return to its pre-exercise state
 This process is known as recovery.
 The old term for this elevated HR was Oxygen Debt,
as it was thought that you had to pay back the oxygen
that you borrowed.
 This analogy is not quite accurate and more up-to-date
terminology is required to explain the process of
recovery.
Oxygen deficit
 It takes the aerobic system a little while to provide
energy for muscular work, even at low intensities.
 During this time, the anaerobic processes must provide
energy.
 Oxygen deficit can be thought of as the extra amount
of oxygen that would be needed to complete the entire
activity aerobically.
 The extra oxygen that the body takes in after exercise
is known as:
 Excessive post-exercise oxygen consumption (EPOC)
The Recovery process
 When you cease to exercise your HR begins to
drop very quickly, but its recovery begins to
slow down very gradually.
 This caused researchers to formulate the idea
that recovery takes place in two stages:
 The fast immediate stage
 A slower longer stage.
Alactic debt
(the fast stage)
 During this stage the energy provided by the
elevated metabolism is used to help the PC
system recover.
 It takes approximately:
 3 mins for the PC stores to fully replenish.
 30 secs for 50% recovery.
 This process requires approximately 4 litres of
oxygen.
Myoglobin
 Myoglobin is a protein molecule similar to
haemoglobin, that helps with the transport of oxygen.
 It is found within the muscle sarcoplasm and helps to
transfer the oxygen from the blood supply to the
mitochondria, where it is needed to fuel aerobic
metabolism.
 It has a higher affinity for oxygen that haemoglobin.
 It takes approx. 0.51secs to replace the oxygen stored
in myoglobin and the process takes 1-2 mins.
 During recovery, with elevated ventilation and HR there
is a surplus of oxygen available for this to occur.
Lactic debt
(the slow stage)
 Lactic acid is removed from the body.
 It can take as long as an hour for all of it to be
removed.
 Lactic acid can be removed in 4 ways:
 60% is converted back to pyruvic acid and enters
the Kreb’s Cycle; it is used in aerobic metabolism
 It can be coverted back to glucose (a process
known as gluconeogenesis that takes place in the
Cori Cycle)
 It can be converted into proteins
 It can be removed via sweating and in urine.
Removal of CO2
 The increased concentration of CO2 formed as
a waste product from the aerobic system has
to be removed from the body.
 The majority of CO2 (70%) is removed in the
plasma of the blood by forming carbonic acid.
 Chemoreceptors detect levels of CO2 /low pH and
stimulate the cardiac and respiratory control
centres. Hence, both cardiac output and respiratory
rate remain higher during recovery to expel the CO2
from the lungs.
Replenishment of
glycogen stores
 Following exercise, glycogen stores in the liver
and muscles will be depleted.
 The only way to replenish these stores is through
ingestion of CHO.
 Often this is through eating, but some athletes have
to take glucose solutions intravenously to replace it
more quickly.
 It can take about 48 hours with a high CHO meal to
totally restore glycogen after a heavy bout of
training.
Implications of recovery for
planning training sessions.
 The restoration of PC is very rapid and full
recovery only takes 2-3 mins.
 If speed work is the specific objective of the training session,
sufficient recovery time should be allowed to ensure full
recovery.
 Use an active cool-down during recovery time.
 Removal of lactic acid is considerably quicker
 Moderate intensity (35% of VO2 max) seems to be most
beneficial
 Monitor training intensities so that OBLA can be
avoided and the quality of training maintained.
 Warm up thoroughly before training.
 This will help reduce oxygen deficit by increasing the oxygen
supply to the working muscles and ensure myoglobin stores
are full.