exercise post oxygen consumption (EPOC) Flashcards
what is steady state
During steady state exercise, the exercise is performed at an intensity such that energy expenditure is balanced with the energy required to perform the exercise.
VO2 max
The maximum or optimum rate at which the heart, lungs, and muscles can effectively use oxygen during exercise, used as a way of measuring a person’s individual aerobic capacity. Taking into consideration the size of the performer.
oxygen consumption
Oxygen consumption (V˙O 2) is the amount of oxygen taken in and used by the body per minute; thus, it is the rate of oxygen use. V˙O 2 is sometimes expressed in liters of O 2per minute (liters per minute).
submaximal o2 deficit
It can be described as the amount of oxygen consumed during recovery more than that which would have ordinarily been consumed at rest
Maximal oxygen deficit (MAOD)
indication of anaerobic capacity
Alactacid component (fast)
The resynthesis of ATP + PC stores in the muscles using oxygen.
Re-saturates myoglobin with o2 (myoglobin has a high affinity for o2 it stores o2 in the sarcoplasm that has diffused Hb from the blood. After exercise o2 stores in the myoglobin are limited. The surplus o2 supplied through EPOC helps replenish these stores- takes up to 2 mins and uses approximately 0.5L of o2.
- Complete restoration of PC stores takes up to 3 minutes
- 50% of PC stores can be replenished after 30 seconds
- 3Ls of o2 are consumed in order for the above to happen
Lactacid component (slow)
- removal of lactic acid (takes place in the following ways)
- When o2 is present lactic acid can be converted back into pyruvate and oxidised into CO2 and H2O in the inactive muscles and organs. This can then be used by the muscles as an energy source. Lactic acid can be transported In the blood to the liver where its converted into blood glucose and glycogen. (the Cori cycle)
- Lactic acid can be converted into protein
- Lactic acid can be removed in sweat and urine
slow component continued
The majority of lactic acid is oxidised in the mitochondria – performing a cool down will accelerate its removal
This takes up to 5-6 liters of o2 in the first half hour of recovery removing up to 50% of lactic acid produced (this can take over an hour to remove all lactic acid produced – depending on the intensity of the exercise)
oxygen deficit
A lack of oxygen in the circulatory systems + mitochondria so you will initially respire anaerobically until you reach steady state vo2.
EPOC (simple)
The volume of oxygen consumed during recovery which would have been consumed at rest during the same time.
EPOC (complex)
This is the excess o2 consumed following exercise which is needed to replace ATP which has been used up and to remove lactic acid created during the previous exercise.
what is the fast component (alactacid component)
- uses oxygen during recovery to restore ATP and PC stores
- Resaturates myoglobin without oxygen (myoglobin has a high affinity for oxygen. It stores oxygen in the sarcoplasm that has diffused Hb from the blood. after exercise oxygen stores in the myoglobin are limited. The surplus oxygen supplied through EPOC helps replenish these stores – takes up to 2 mins and uses approx.. O.5l of oxygen.
slow component (lactacid component)
- When oxygen is present lactic acid can convert back into pyruvate and oxidised into carbon dioxide and water in the inactive muscles and organs. This can then be used by the muscles as an anergy source.
- Lactic acid can be transported in the blood to the liver where it is converted to blood glucose and glycogen (The Cori cycle)
- Lactic acid can be converted into protein.
- Lactic acid can be removed in sweat and urine.
maintenance of breathing and heart rate
- After heavy exercise you continue to breathe heavily, and your HR slowly decreases in order to supply oxygen to your heart and respiratory muscles in order to assist recovery.
- Extra oxygen is used to replenish ATP and PC stores, resaturate myoglobin and remove lactic acid – returning the body to its pre-exercise state.
- Energy is needed for a high heart rate and breathing rate
glycogen replenishment
- Glycogen is the main energy provider for both the aerobic and anaerobic glycolytic energy systems.
- Glycogen is depleted during exercise.
- The replacement of glycogen stores depends on the type of exercise undertaken and when and how much carbohydrate are consumed following exercise.
- It may take several days to restore glycogen after a marathon but after less than an hour a significant amount of glycogen can be restored when lactic acid is converted back to blood glucose and glycogen in the liver via the Cori cycle.
- Eating a meal high in carbohydrates will accelerate glycogen restoration as well as eating within an hour after exercise.
- There are two nutritional windows for optimal recovery after exercise:
1. 30 mins after exercise carbohydrates and protein should be consumed in a 3:1 or 4:1 ratio. This combination helps the body to re-synthesize muscle glycogen more efficiently (e.g., athletes will drink a chocolate milkshake after exercise)
2. 1 – 3 hours after exercise a meal high in protein, carbohydrate and healthy fat should be consumed.
