Energy for exercise Flashcards
(15 cards)
Describe the characteristics of the ATP/PC system?
Reaction = anaerobic
Fuel = phosphocreatine
Site = sarcoplasm
Enzyme = creatine kinase
Yield = 1:1
Byproduct = none
Intensity = very high
Duration = 2-10 seconds
Stages = PC - P + C + energy
energy + ADP + Pi - ATP
What are the strengths and weaknesses of the ATP/PC system?
Strengths:
- no O2 delay
- PC readily available
- simple + rapid
- no fatiguing byproducts
Weaknesses:
- low ATP yield
- small PC stores = rapid fatigue
What are the characteristics of the glycolytic system?
Reaction = anaerobic
Fuel = glycogen/glucose
Site = sarcoplasm
Enzyme = GPP, PFK, LDH
Yield = 2:1
Byproduct = lactic acid
Intensity = high
Duration = 10s-3minutes
Stages = glucose undergoes glycolysis
pyruvic acid - lactic acid
What are the strengths and weaknesses of the glycolytic system?
Strengths:
- no O2 delay
- large fuel store
- high intensity
- lactic acid can be recycled
Weaknesses:
- fatiguing byproduct
- relatively low yield
- lengthy recovery
What are the characteristics of the aerobic system?
Reaction = aerobic
Fuel = glycogen/glucose
Site = sarcoplasm, matrix, cristae
Enzyme = PFK and coenzyme A
Yield = 38:1
Byproduct = CO2 + H20
Intensity = low
Duration = above 3 minutes
Stages = glycolysis, krebs, electron transport chain
What are the strengths and weaknesses of the aerobic system?
Strengths:
- large fuels
- high ATP yield
- large duration
- no fatiguing byproducts
Weaknesses:
- delay for O2
- complex reaction
- slow energy production
What is recovery?
Returning the body to it’s pre-exercise state
What is EPOC?
Volume of O2 consumed post exercise to return the body to a pre-exercise state
What happens in the fast alactacid stage of recovery and how long does this take?
Replenishment of PC stores and blood and muscle O2
Takes up to 3 minutes
How long does phosphocreatine replenishment take?
- 3 minutes for full PC recovery
- 30s for 50% and 60s for 75%
- requires approximately 3-4L of O2
How long does replenishment of blood and muscle O2 take?
- 1st minute O2 re-saturates blood associating with haemoglobin
- 3 minutes in oxymyoglobin links are restored in the muscle cells
What happens during the slow lactacid stage of recovery and how long does this take?
Elevated ventilation, circulation and temperature and removal of lactic acid
3 minutes up to 24 hours
What is the purpose of elevated ventilation and circulation?
- respiratory rate, depth and HR remain elevated
- they gradually decrease to resting levels
- maximises O2 delivery and byproduct removal
What is the purpose of elevated temperature?
- increases metabolic rate
- accounts for 60-70% of slow component
How is lactic acid removed from the body?
- 50-70% converted back into pyruvate to enter the krebs cycle
- 10-25% converted back into glucose/glycogen
- converted into proteins
- removed via sweating and urine
