The recovery process
This refers to the processes that occur to restore the body to a
pre-exercise state.
After exercise heart rate and respiration remain higher than
resting values.
This elevated heart rate and respiration is known as EPOC – Excess
Post exercise Oxygen Consumption.
We have stopped exercising but our heart rate and breathing rate
are still elevated. The reason for this is that some of the changes
that occur in our bodies during exercise need O2 to restore to
resting values – so the heart rate and respiration remain high until
resting values are achieved. This is also known as repaying the
oxygen debt.
There are two stages to the recovery process:
1 Alactacid component (fast)
2 Lactacid component (slow)
Alactacid component
- Restore ATP and PC (sometimes known as muscle phosphagens)
To restore ATP and PC takes approx. 3 to 4L of O2.
50% of PC is restored in 30 secs
75% of PC is restored in 1 min
100% takes approx 3 mins
Restore oxy-myoglobin within the muscle (myoglobin combines with
O2 ready to take O2 to the mitochondria when exercise begins
again) approx 0.5L of O2 for full recovery. Takes 1-2 mins.
Lactacid component
Requires 5 – 8 L of O2 (depending on the exercise intensity and
therefore the amount of lactic acid to remove)
- Remove/convert lactic acid:
65% oxidised (broken down to CO2 and H2O) and removed
20% converted into glycogen and stored (ready for exercise)
10% converted into protein
5 % converted into glucose (used to provide energy during
recovery process i.e. rebuild ATP and PC)
During an active recovery more O2 flushes out the muscles of lactic
acid – this can take 5 – 6 L of O2.
Removal of lactic acid takes approx 60 mins with an active recovery
(cool down). This is doubled without an active recovery.
-
Remove CO2
Increased heart rate and respiration helps remove the high
levels of CO2.
Most CO2 is carried in the plasma within red blood cells – (CO2
combines with water forming carbonic acid)
Some CO2 carried by haemoglobin
Some dissolved in the plasma
- Restore glycogen
Most glycogen stores can be restored within 10 – 12 hours.
To aid glycogen restoration a high carbohydrate meal should be
consumed within an hour of ceasing exercise.
How long restoration will take will depend on the type and duration
of the exercise – therefore the amount of glycogen depleted.
After a marathon – where muscle and liver glycogen stores are
almost totally depleted restoration can take several days.
Other processes occurring during recovery:
- Restore resting heart rate / stroke vol. / cardiac output
- Restore resting ventilation – breathing depth and rate (tidal
volume and frequency) and minute ventilation.
- Restore temperature to resting values.
Implications of the recovery process for planning
training sessions.
PC takes 3 min for full restoration and 30 secs for 50%. To increase
PC stores, full recovery should be prevented. E.g. interval training
30m high intensity sprint with 30 secs recovery.
Speed work – allow full recovery between work intervals (2-3 mins)
Warm up increases respiration and reduces the oxygen deficit (the
difference between the O2 required for the exercise intensity and
the actual O2 supplied –difference accounted for by the limited
ability to supply energy aerobically at the beginning of exercise, and
anaerobic exercise)
Active recovery (moderate intensity) removes lactic acid more
quickly after exercise which involved anaerobic work.
After aerobic work no active recovery is necessary (passive
recovery), active recovery can slow down recovery.
Opportunities for breaks in training and performance should be
maximised to allow restoration of PC, ATP and oxymyoglobin.
Opportunities within team sports are particularly important for
improved performance. E.g. Props in rugby ‘going down injured before
important scrums’ – allowing full or nearly full recovery of PC.
Aerobic training will improve O2 supply during activity limiting
oxygen debt and increase recovery time after exercise or between
bouts of anaerobic work during team sports.
A mix of anaerobic and aerobic training will help delay the ATP/PC
and lactic acid thresholds – improving performance.
Heart rate monitors can be used to monitor work intensity and when
thresholds are reached – this can be used to prevent OBLA from
occurring. This will help limit recovery time.
Summary
2 components alactacid (Fast) and lactacid (slow)
Fast:
Restore ATP and PC
Restore oxymyoglobin
Slow:
Remove lactic acid
Remove CO2
Restore glycogen stores
Others:
HR, SV and Q resting values restored.
F, TV and VE resting values restored.
Normal resting body temperature restored.
Exam tip:
- Be able to explain EPOC / O2 debt
- Describe the 2 components of the recovery process
- Explain the implications of the recovery process for
training ( inc.different intensities/work and rest
duration during interval training).
Familiarise yourself with EPOC diagram/graph – showing O2
consumption and time / O2 deficit / exercise VO2 uptake /EPOC
components (alactacid and lactacid). P384 in textbook.
Question – At the end of a team game players will experience
EPOC. Define EPOC, give the function of the alactacid and
lactacid components of EPOC, and explain how these functions
are achieved.
(7 marks)
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