Transcript Recovery Following Exercise

Recovery Following Exercise
Objectives:
Define EPOC
Explain why there will always be an
oxygen deficit
Explain what the excess oxygen is
being used for in the fast and slow
replenishment stages
Acronyms game
What do each of these acronyms stand for / mean?
PCr, R.E.R, OBLA, VO2
max, ATP, PFK, ADP,
EPOC?
EPOC
What happens to an athlete’s
cardiorespiratory system during
exercise?
Why?
What happens after exercise? Why?
Following exercise…
… regardless of the type of exercise performed,
breathing rates will remain elevated during recovery.
This is called the excess post-exercise oxygen
consumption (EPOC)…
…and it enables the body to replenish ATP and PC stores,
remove lactic acid and restore muscle oxymyoglobin
levels.
Excess Post-Exercise Oxygen
Consumption (EPOC)
• EPOC is the total volume of oxygen that is consumed
after exercise which enables the body to fully recover
and return to its pre-exercise state.
•It includes the oxygen debt which is oxygen that is
used to restore muscle ATP and PC, and remove lactic
acid.
•It also includes the oxygen required to keep breathing
and heart rates elevated, and the oxygen restored to
muscle myoglobin.
Oxygen Debt
An oxygen debt will occur…
… when the body has exercised anaerobically, either at
the start of any exercise before the aerobic system
kicks in, during intense exercise lasting up to 3 mins, or
when the anaerobic threshold has been exceeded.
The oxygen debt is used to compensate for the oxygen
deficit – the amount of extra oxygen that would have
been required to complete the exercise aerobically.
As aerobic respiration does not happen for the first 3
mins of exercise, a deficit will always occur.
EPOC and Oxygen Deficit can be easily shown on a graph
of Oxygen Consumption during exercise:
VO2
(L/min)
Sub-maximal Exercise
Recovery
It does not necessarily follow that EPOC will equal
deficit, as extra oxygen is required post exercise to:
• Supply oxygen to re-saturate muscle myoglobin stores
• Supply energy for the increased cardiac and respiratory
rates that remain elevated during the recovery phase
Consequently the amount of oxygen consumed during the
EPOC is greater than that which might have been
consumed during the oxygen deficit.
The excess post-exercise oxygen consumption (EPOC) has
two components:
1. The fast replenishment stage (alactacid debt)
2. The slow replenishment stage (lactacid debt)
The fast replenishment stage
• This is the first component of the oxygen debt that is
replenished and requires up to 4 litres of oxygen.
•Within this component, the very first amount of oxygen
consumed is used to resaturate myoglobin with oxygen.
•The rest of the oxygen is required to produce sufficient
energy from aerobic respiration to restore the muscle ATP
and phosphocreatine stores
•It takes a short amount of time (2-3 mins) for this to be
replenished
•This means that after a short (<10s) bout of intense work,
the body will be sufficiently recovered after 3 mins to
repeat the exercise
Interval training plays on this quick replenishment of
phosphagens
Training can increase muscle PCr and ATP stores.
The Slow replenishment stage (Lactacid Debt)
 Can take up to 2 hours and require 5-10 litres of oxygen
which is used to do 4 main things:
1. Maintain the elevated heart and respiratory rates
2. Remove lactic acid from the muscles
 Most (65%) LA is converted into pyruvate and
oxidised into CO2 and H2O through aerobic
respiration – this requires oxygen!
 Typically this process of lactic acid removal takes
approx 1 hour, but it can be accelerated by a cool
down which ensures a rapid and continuous supply of
oxygen to the muscles
EFFECT OF COOL-DOWN ON LACTIC ACID REMOVAL
REMOVAL OF LACTIC ACID FOLLOWING EXERCISE
• cool-down continues to provide oxygen to skeletal muscle
• which therefore enhances oxidation of lactic acid
• and ensures that less lactic acid remains in tissue
• and there is less muscle soreness
The Slow replenishment stage (Lactacid Debt)
 3. Replenish muscle glycogen stores:
 This depends on the type of exercise performed and the
amount and timing of carbohydrate consumption following
exercise
 Continuous endurance activity: little glycogen
replenishment immediately after exercise, and can take up
to 48 hours
 High intensity short duration exercise: significant
muscle glycogen replenished within 30-60mins and all
within 24hrs
 Due to conversion of LA back into glycogen via cori cycle
 Replenishment occurs much more rapidly if a high carbs
meal (200-300g) is consumed within 45-60mins after
exercise – the carbohydrate window
The Slow replenishment stage (Lactacid Debt)
4. Meet the increased metabolic demands associated with
an elevated body temperature
 A 10˚C rise in body temperature doubles the rate of
metabolic reactions
 Body temp doesn’t change this much, but metabolism
does speed up meaning more oxygen is required!
Task:
Exam Questions
Q1- Outline the function and process of the fast component of the
recovery process.
(4 marks)
Q2- The Graph shows the oxygen consumption (VO2) of a subject
during a period of rest, sub maximal exercise and recovery.
a) (i) State which letter (A–F)
represents oxygen deficit and
which letter (A–F) represents
EPOC.
(2 marks)
(ii) How long did the exercise
last and what does letter F
represent?
(2 marks)
(b) EPOC consists of fast and
slow components. What are
the functions of the slow
component and how are these
functions achieved? (3 marks)
Q14 marks for 4 of:
A. EPOC explanation – volume of oxygen
consumed in recovery above the resting rate
B. The alactacid/alactic (debt/component)
C. Re-saturation of myoglobin/haemoglobin
with oxygen
D. Re-synthesise ATP/PC levels
E. Uses 2-4 litres of oxygen
F. Completed in 2-3 minutes
G. 50% PC stores replenished within 30
seconds/75% within 60 seconds
A – NOT repay oxygen debt
A – NOT removes lactic acid
Allow a few minutes
Q2(a)(i)
(ii)
(b)
1. Deficit . B;
2. EPOC . C. (Credit first two letters only)
2 marks
1. Duration = 14 mins;
2. F = steady state/period when VO2 remained
constant/consumption = requirement/supply and demand.
(Do not credit VO2 max/max VO2/plateau)
2 marks
1. Slow. extra oxygen needed;
2. For removal/breakdown of lactate/buffering;
3. For supply to/maintain breathing muscles;
4. For supply to/maintain heart muscles;
5. Lactate mainly converted back into pyruvate;
6. Oxidised to CO2 and water;
7. Produces ATP (to credit must link back to 6 or 7)
8. In inactive muscles other organs (liver);
9. Some lactate converted to glucose/glycogen/protein;
11. Some excreted in urine and sweat.
Homework: Revision for exam next
lesson.
Complete the key terms sheet with
detailed explanations for each term
AND
Produce detailed, neat, colourful
revision notes with diagrams.
2 sides of A4 max.