Energy Transfer During Long Duration / Low Intensity Exercise

Question 1

Oxygen consumption: maximal and submaximal oxygen deficit

Answer 1

• start of EX use more o2 to provide more ATP so the o2 consumption increases
• start of EX energy is provided anaerobically to satisfy the increase in demand for energy until the circulatory system and mitochondria can cope = submaximal oxygen deficit
• maximum o2 deficit is usually referred to as maximal accumulated oxygen deficit or MAOD.
  . Gives indication for anaerobic capacity.

Question 2

Oxygen consumption during recovery (EPOC)

Answer 2

• recovery = returning the body to its pre-exercise state
• the breathlessness after exercise is referred to as EPOC

Question 3

Fast component of EPOC

Answer 3

• uses extra o2 that is taken in during recovery to restore ATP and phosphocreatine + re-saturate myoglobin with o2.
• complete restoration of phosphocreatine takes up to 3 minutes but 50% can be replenished after only 30 seconds
• myoglobin has a high affinity for o2 - stores o2 in the sarcoplasm that has diffused from the Hb in the blood
• after EX o2 stores in the myoglobin are limited - the surplus of o2 supplied in EPOC helps replenish these stores, taking up to 2 minutes and using approx 0.5 litres of o2.

Question 4

What are the functions of the slow component of EPOC

Answer 4

1. Removal of lactic acid
2. Maintenance of breathing and heart rate
3. Glycogen replenishment
4. Increase in body temperature

Question 5

Describe the removal of lactic acid in the slow component

Answer 5

• L.A accumulates during EX and needs to be removed
  L.A can be removed in the following ways:
  . O2 present - L.A can be converted backn into pyruvate and oxidised into Co2 and H2O in the inactive muscles and organs + used by the muscles as an energy source
  . Transported in the blood to the liver where it is converted to blood glucose and glycogen
  . Converted into protein
  . Removed in sweat and urine

Question 6

Describe the maintenance of breathing and heart rate in the slow component

Answer 6

• requires extra o2 to provide the energy needed for the respiratory and heart muscles
• assists recovery as the extra o2 used to replenish ATP and phosphocreatine stores, re-saturate the myoglobin and remove L.A

Question 7

Describe the glycogen replenishment in the slow component

Answer 7

• as glycogen is the main fuel for both the aerobic and anaerobic glycolytic systems - depleted during EX
• the replacement of glycogen stores depends on the type of EX and when and how much carbs is consumed following EX
• glycogen can be replaced in less than an hour after high duration, short intensity EX, glycogen can be replaced quickly as L.A is converted back to blood glucose and glycogen in the liver via the cori-cycle
• 2 nutritional windows for optimal recovery
  1. 30 mins after exercise - both carbs and proteins = helps body re-synthesise muscle glycogen more efficiently rather than just carbs
  2. 1-3 hours after exercise = meal high in protein, carbs and healthy fat.

Question 8

Describe the increase in body temperate in the slow component

Answer 8

• when temp remains high, respiratory rates remain high, so it will help the performer take in more o2 during recovery.
• however extra o2 is needed to fuel this increase in temp until the body returns to normal