Energy systems Flashcards
What does measuring OBLA do?
- gives an indication of endurance capacity
- higher levels of fitness Delay OBLA/lactate threshold
How does the Anaerobic Glycolytic System Provide energy ?
- glycogen broken down by enzymes into glucose.
- Glucose is broken down enzymes into Pyruvic acid.
- 4 ATP is created, 2 used for glycolysis and 2 for muscle contraction
- When O2 is not present, Pyruvic acid is broken down into Lactic acid.
At what intensity is the ATP-PC system used?
- High intensity
How long does the ATP-PC system last?
- 10-12 seconds
What are the stages of the ATP-PC system?
- Phosphocreatine is broken down into phosphate and creatine
- Using the phosphate, ATP is resynthesized
- The breakdown of the ATP produces energy with a by-product of creatine.
What is OBLA?
- the point when lactate levels go above 4 millimoles per litre
- intensity increases = body unable to produce enough oxygen to break down lactate
How long is the recovery process of the ATP-PC system and what sporting activities is it used?
- 30 Secs
- 100m
- shot-put
How long does our ATP store last?
- 2 seconds
Give 3 examples of when the anaerobic glycolytic system is used in sport
- 200m
- 400m
- games sports
How long is the recovery process of the anaerobic glycolytic system?
- up to 1 hour
What is the duration intensity of the anaerobic glycolytic system?
- High intensity
- medium duration
What happens when ATP is broken down?
- it leaves the compound of ADP (adenosine triphosphate)
What are the 3 stages in the aerobic system?
- glycolysis
- krebs cycle
- electron transport stage
What is involved in the Electron transport chain Stage ?
- hydrogen is oxidised to water and enough energy is resynthesized to produce 38 ATP.
what 2 energy systems are used in the aerobic system?
- Glucose
- Triglycerides
How is glucose used as the aerobic energy system?
- Glucose is broken down into pyruvate via glycolysis. enough energy is produced to resynthesise 2 ATP.
- pyruvate is converted into Acetyl CoA
- Acetyl CoA enters krebs cycle.
- Produces citric acid and hydrogen ions and 2ATP
- hydrogen ions get oxidised into water and enough energy to resynthesize 38 ATP
How is glucose used as the aerobic energy system?
- Glucose is broken down into pyruvate via glycolysis. enough energy is produced to resynthesise 2 ATP.
- pyruvate is converted into Acetyl CoA
- Acetyl CoA enters krebs cycle.
- Produces citric acid and hydrogen ions and 2ATP
- hydrogen ions get oxidised into water and enough energy to resynthesize 38 ATP
How are triglycerides used in the aerobic energy system?
- Triglycerides are broken down into glycerol + fatty acids
- glycerol + fatty acids broken down into Acetyl CoA via beta oxidation
- Acetyl CoA enters krebs cycle.
- Produces citric acid and hydrogen ions and 2ATP
- hydrogen ions get oxidised into water and enough energy to resynthesize 38 ATP
3 Advantages of the ATP-PC system
- quick release of energy
- no need for O2
- No harmful by-products
2 Advantages of the Anaerobic glycolytic system
- relatively quick release of energy
- no need for O2
3 Advantages of the aerobic system
- Can be used with multiple energy stores
- no harmful by-products
- If we have an energy store it can be used indefinitely
Disadvantages of the ATP-PC system
- not used for long
- recovery takes 30 seconds
- limited energy stores
Disadvantages of the Anaerobic glycolytic system
- harmful by-products
- full recovery takes over an hour and requires O2
Disadvantages of the aerobic system
- needs O2
- takes a long time for energy to be produced
What is Arterio-Venous Difference (A-VO2 diff)?
- the difference between the oxygen content of the arterial blood arriving at the muscle and the venous blood leaving the muscle
What is EPOC?
- Excess post-exercise oxygen consumption
- O2 debt- the amount of oxygen consumed during recovery above that which would have been consumed at rest during the same time
What is involved in the Glycolysis Stage?
- It is the breakdown of glucose into pyruvic acid
- enough energy is produced to make 2 ATP.
Why does the size of EPOC change?
- it changes because you need more O2 to remove lactic acid.
-
when is EPOC used?
- fast and slow replenishment stages
- re-saturates myoglobin and replenish ATP stores
What happens in the slow replenishment stage of EPOC
- maintain breathing rate and heart rate
- Body temperature stays elevated
- This helps to remove lactic acid and replenish muscle glycogen
What is VO2 max
- The amount of O2 that can be consumed and utilised by the working muscles per minute
What are the stages of the fast replenishment stage?
- uses the extra oxygen taken in during recovery to restore ATP and phosphocreatine, and to re-saturate myoglobin with oxygen.
- Complete restoration of phosphocreatine takes up to 3 minutes
- 50% of stores can be replenished after only 30 seconds.
- The process uses 2–3 litres of oxygen.
How is lactic acid removed in the slow replenishment stage?
- oxidation of CO2 and water in the inactive muscles are used as energy stores
- transported into the blood and enters the cori cycle
- Cori cycle turns this into glucose and glycogen
- This is turned into protein and removed via sweat
How does a cool-down help with the removal of lactic acid?
- exercise keeps the metabolic rate of muscles high and keeps capillaries dilated
- allows O2 to be flushed through and removes lactic acid
What is the lactate threshold?
- It is the exercise intensity at which lactic acid begins to increase rapidly in the blood.
What is the the LT of an average performer?
- 50-60% of their VO2 max
What is the LT of an elite performer?
- 70-90% of their VO2 max
What is an effect of fitness on LT
- The fitter we are, the higher our LT is as a percentage of our VO2 max
- it means we can work harder
Name factors which affect VO2 max/aerobic power
- higher VO2=bigger endurance capacity
- allows for the performer to work at a high intensity for longer due to more O2 to muscles
Physiological factors affecting VO2 max
- Increased cardiac output
- increased stroke volume + cardiac hypertrophy
- Less O2 consumption from the heart so more for muscles
- Increased haemoglobin and red blood cells
What is the effect of training on VO2 max?
- aerobic training can improve VO2 max by up to 10-20%
- results in an increase in the efficiency of oxygen transport within the body.
What is the effects of genetics on VO2 max?
- VO2 is genetically determined
- genetics can account for as much as 47% of the inter-individual variance in training responses
- The genes impact cardiorespiratory endurance:
- regulation and adaptation of the cardiovascular system, lactate clearance, mitochondrial function
What is the effects of age difference on VO2 max
- VO2 lowers with age because our body becomes less efficient
- 1% decrease each year
What is the effects of gender on VO2 max?
- Men have a 20% higher VO2 max than women
What is the effects of body composition on VO2 max?
- A higher % of body fat decreases VO2 max
- An increase in lean body mass contributes to strength and power development.
How does a lifestyle effect VO2 max?
- Smoking, poor diet, sedentary lifestyle poor fitness have negative effects on VO2 max
What is a test to measure VO2 max?
- Incremental treadmill test
- Harvard step test
- Cooper 12 min run
What is an indirect calorimetry test?
- It is an accurate estimate of energy expenditure via gas exchange
What is lactate sampling?
- it is an accurate and objective measure of lactate in the blood
What does RER stand for, and what is it?
- Respiratory Exchange Ratio
- It measure the Ratio of CO2:O2 consumed
What are the RER values?
- RER value close to 1 -> carbs used
- RER value approximately 0.7 -> fats used
- RER greater than 1 -> anaerobic respiration occurring; more CO2 produced than O2 consumed
What does indirect calorimetry measure?
- measure amount of CO2 produced
- amount of O2 consumed at rest and aerobic exercise
What does lactate sampling measure?
- can measure exercise intensity
- measures the lactate build up in the blood
What do the results of a lactate threshold test tell us?
- A lower lactate at the same intensity of exercise means the performer has had an:
- increase in peak speed + power
- increase time to exhaustion
- Increased recovery rate
- improved lactate threshold
What do gas volumes tell us about in indirect calorimetry?
- they can help find the main substrate being used?
Advantages of indirect calorimetry
- accurate
- helps find main substrate being used
Advantages of RER
- Helps find the source being used
- Accurate
Advantages of VO2 max
- When special equipment is being used it is accurate
Advantages of lactate threshold
- Accurate and objective
- can be more realistic
Disadvantages of Indirect calorimetry
- Expensive
- Doesn’t replicate competition due to the stationary equipment
Disadvantages of RER
- Expensive
- Doesn’t replicate competition
Disadvantages of VO2 max
- When no equipment is used it isn’t as accurate
Disadvantages of lactate sampling
- may require athlete consent
What are the advantages of altitude training
- increased EPO prod
- increased red blood cell prod
- increased O2 carrying capacity
- increased VO2 max
- improved aerobic performance
Disadvantages of altitude training are?
- phycological issues due to being away from home
- Altitude sickness
- Detraining
- Lose benefits quickly when you return to normal altitude
- Expensive
What is detraining?
- this is where we have put ourselves in an environment with less O2
- less effective as you cannot train with as high intensity as normal
Why is altitude training effective?
- Low PP of O2
- Makes body adapt to cope with the environment
What is HIIT training?
- High Intensity Interval Training
- Periods of anaerobic work and aerobic work
How does HIIT training work?
- Anaerobic work followed by periods of aerobic work
- aerobic work acts as a break
- Enables body to adapt and recover the anaerobic glycolytic system
Advantages of HIIT training are?
- increased lactate buffering capacity
- replicates sport
- can be personalised
- increases aerobic power and CV endurance
What are the disadvantages of HIIT training?
- work/rest intervals differ by position which makes it difficult to calculate
- high intensity reduces the skill quality
- can lead to injury
What is plyometric training?
- are exercises in which muscles exert maximum force in short intervals of time
- jumping, hopping, bounding causes repeated, rapid contractions to occur
- increases power
What is the process in the shortening cycle?
1) eccentric phase- when landing an eccentric contraction occurs
2) amortisation phase- this is the time between eccentric and concentric contraction
3) muscle contraction phase- stored energy is used to increase the force of contraction
What are the advantages and disadvantages of plyometrics?
- increases speed and force of contraction
- increases no. type IIx Muscle Fibres
- can cause injury due to large strain on joint
- more suited to legs
What is SAQ training?
- Multi directional movement aimed at improving neuromuscular system
- more suited to games players
How does SAQ work?
- movements fire up the motor neurons and contracts the muscle fibres.
- This increases the speed of contractions
what are the advantages and disadvantages of SAQ training?
- Can be tailored to a specific sport
- improves Speed, Agility, Quickness
- needs equipment to be effective
Explain how energy is produced in a 400m race. (3 marks)
- Energy is produced via the anaerobic glycolytic system
- Glycogen is broken down into glucose via PFK enzyme
- glucose is broken down into pyruvate and energy through glycolysis.
- This process is anaerobic and therefore produces lactic acid as a by-product
Explain how triglycerides are used as an energy source during an open water swimming event. (4 marks)
- Triglycerides are an aerobic system and so they use O2
- triglycerides are broken down into glycerides and fatty acids via beta oxidation
- Acetyl CoA produced and enters Krebs cycle which produces energy.
Describe the processes that occur in the slow replenishment stage of EPOC. (4 marks).
- HR and respiratory rate stay high to keep O2 flowing
- Body temp stays high to keep the speed of chemical processes high
- lactic acid is removed by oxidising carbon dioxide in the inactive muscles to be used as an energy store
- enters the cori cycle, turning it into glucose and glycogen.
What is the difference between OBLA and lactate threshold? (2 marks)
- OBLA is lactate accumulation to 4mmols/l
- LT is lactate accumulation to 2mmols/l above resting level
- LT is relative to an athlete’s resting level of lactate whereas OBLA is absolute.
