1.1 Energy Systems Flashcards
What is adenosine triphosphate (ATP) and how is energy produced from it
- The only usable form of energy in the body
- ATPase (enzyme) breaks down ATP into ADP (adenosine di-phosphate)
How long does stored ATP in the muscles provide the body with energy
2-3 seconds
What are the 3 energy systems
- ATP-PC system
- anaerobic glycolytic
- aerobic
Intensity and duration of the ATP-PC system
- maximal high intensity
- > 10 seconds
Intensity and duration of the anaerobic glycolytic system
- mid to high intensity
- 2-3 mins
Intensity and duration of the aerobic system
- low intensity
- duration 2 minutes to hours
Explain how the ATP-PC system works
- phosphocreatine broken down into phosphate and creating by creating kinase (enzyme) creating energy
- this energy is then used to combine ADP with phosphate to make 1 ATP
Advantages of the ATP-PC system
- ATP can be re synthesised rapidly
- phosphocreatine stores can be replenished quickly 50% in 30 seconds 100% in 3 minutes
- no fatiguing by products
- ATP-PC system can be boosted through creating supplements
Disadvantages of the ATP-PC system
- only lasts 10 seconds
- low ATP yield only 1
- PC can only be resynthesised in the presence of oxygen (when intensity drops)
What is the anaerobic glycolytic system
Glycogen from the liver/muscle is broken down into glucose
Glucose is then further broken down by the enzyme (PFK) into pyruvic acid
This produces 2 ATP and in the absence of oxygen lactic acid
Advantages of the anaerobic glycolytic system
- ATP resynthesised fairly quickly
- lasts longer than the ATP-PC system
- in the presence of oxygen lactic acid can be converted back into glycogen or be used as fuel through oxidation
Disadvantages of the anaerobic glycolytic system
- lactic acid is a fatiguing byproduct
- only small yield of ATP out of the glycogen
Explain how the aerobic system produces energy
Three stages:
1. Glycolysis - glycogen broken down into glucose which is broken down by PFK into pyruvic acid
Before stage two the pyruvic acid is oxidised into two acetyl groups
2. Kerbs cycle- the acetyl groups are carried by coenzyme A into the matrix of the mitochondria where they combine with oxaloacetic acid to from citric acid, creates 2 ATP and byproducts of carbon dioxide and hydrogen
3. Electron transport chain - hydrogen split into ions and electrons, ions are oxidised to make water and the electrons provide energy to resynthesise 34 ATP
Advantages of the aerobic energy system
- high ATP yield 38
- no fatiguing by products
- can last a long time
Disadvantages of the aerobic energy system
- complicated system can’t be used straight away, takes a while for oxygen levels to meet the demand of the exercise
- can’t be used at high or maximal intensities
define oxygen consumption
the amount of oxygen we use to produce ATP (VO2)
what is meant by VO2 max
the maximum volume of oxygen that can be taken up by the muscles per minute
what is the volume of oxygen consumption at rest
0.3-0.4 litres per minute
what is the range of maximal oxygen consumption when exercising
3-6 litres per minute
explain how oxygen deficit is created
when exercise is started the aerobic system is not meeting the oxygen demands, this means energy must be created anaerobically. this can come on different scales.
sub-maximal oxygen debt
maximal accumulated oxygen deficit (MAOD)
what are the two components of EPOC
fast component
slow component
what is meant by EPOC
- excess post-exercise oxygen consumption
- returns the body to its pre-exercise state
outline the fast component of EPOC
- occurs 2-3 minutes following the event
- uses around 1-4 litres of O2
- restores PC stores
- restores oxygen in the myoglobin
outline the slow component of EPOC
- can take up to an hour or longer
- removal of lactic acid
- glycogen replenishment
- maintains HR and BR
what is OBLA
Onset Blood Lactate Accumulation
- when lactate levels go above 4 millimoles per L
- above 4 breaches the threshold that a performer can manage and causes rapid lactate build-up
- this is around the same in every individual
- HOWEVER each individual reaches OBLA at a different intensity
- well-trained athletes with a high VO2 max will reach higher intensities before they reach OBLA
what physiological factors affect the rate of lactate accumulation
- exercise intensity (higher intensity, faster OBLA)
- muscle fibre types (slow twitch, less lactate)
- the rate of blood lactate removal
- the respiratory exchange ratio
- fitness of the performer (fitter person, OBLA delayed)
what are the factors affecting VO2 max
- cardiac hypertrophy, leading to higher SV,Q and ejection fraction
- increased myoglobin, haemoglobin, red blood cells, mitochondria
capillary density
how is lactic acid removed during the slow component of EPOC
- coverted back into pyruvate and CO2 and water in the presence of oxygen
- transported to the liver to be turned into glycogen or glucose
- converted into protein
- removed in sweat and urine
what is meant by buffering
- process that aids the removal of lactate and maintains acidity levels
- allows athletes to work at higher intensities for longer as OBLA is delayed
- they fatigue slower
what are the non-physiological factors affecting VO2 max
- gender (males tend to have higher VO2 maxes)
- age (VO2 gradually declines with age)
- lifestyle choices (smoking destroys alveoli reducing VO2 max)
- genetics, children tend to inherit similar VO2 maxes to their parents
- training, aerobic training can improve VO2 max by 10-20%
what are the 4 measures of energy expenditure?
- indirect calorimetry
- lactate sampling
- VO2 max test
- respiratory exchange ratio
what is lactate sampling
- taking a small sample of the blood when the athlete is completing the activity
- shows the number of millimoles of lactate in the blood at a given time
- can be used to identify when the performer hits OBLA, this is an indication the performer is beyond their VO2 max and is now using their anaerobic energy systems
- can also be used to ensure the athlete is training at the correct intensity
what is the respiratory exchange ratio
- the ratio of carbon dioxide produced compared to oxygen consumed
- requires the athlete to be attached to a gas analyser whilst on a treadmill
= VCO2 / VO2 - indicates fuel usage during exercise
- around 0.7 indicates fat is the predominant fuel source (lower intensity)
- around 1 indicates carbohydrates in the predominant fuel source (higher intensity)
- over 1 is an indication of anaerobic exercise (even higher intensity)
what is indirect calorimetry
- measure of CO2 production and O2 consumption
- can be used to calculate the respiratory exchange ratio
- gives an accurate objective measure of VO2 max
- can be used to monitor progress
what is a VO2 max test
- could be in the form of the bleep test or Cooper run in which the performer goes until exhaustion
- the level reached is then compared to a chart
- OR gas analysis in a lab could be used to provide more reliable and valid results
- in which a performer reaches exhaustion whilst their CO2 production and O2 consumption is measured
what is altitude training
- training above 2500m above sea level where the partial pressure of oxygen is lower
- this leads to the body making adaptations to increasing its oxygen-carrying capacity
- such as increased EPO, increased red blood cells, increased myoglobin, increased capillarization
evaluate altitude training
+ allows athletes to work at higher intensities for longer
+ delays OBLA
+ quicker recovery/buffering
- benefits are quickly lost when they return to sea level
- hypoxia (altitude sickness)
- initial loss of performance
- psychologically challenging being away from home
what is plyometric training
- the use of explosive movements like hopping, jumping, bounding to train the muscles fast twitch fibres
3 stages: PAM
1 Pre-loading - an eccentric contraction that stretches the muscle
2 Amortisation - the time between eccentric and concentric contraction, needs to be short so the stored energy from the eccentric contraction can be used
3 muscle contraction- concentric contraction is more explosive because the muscle spindle trigger the stretch reflex
evaluate the use of plyometric training
+ builds power
+ develops anaerobic systems
+ develops fast twitch fibres
+ can replicate sport-specific movements
- it may be difficult to replicate some movements
- high risk of injury
what is HIIT
- high-intensity interval training involves periods of high-intensity work followed by short periods of rest
- the training can be altered to be most suitable by …
1 changing duration of work
2 changing duration of rest
3 changing intensity/speed of work
4 changing number of work/rest intervals
evaluate HIIT training
+ trains both aerobic and anaerobic energy systems
+ dynamic and adaptable
+ increases performer’s lactate tolerance
- high intensity increases risk of injury
- not as appropriate for an aerobic endurance athlete
what is SAQ training
- speed agility and quickness training aims to improve multi-directional training
- may involve ladders and zig-zag movements
evaluate SAQ
+ increases power and agility
+ Improved reaction time
+ Better spatial awareness
+ trains anaerobic energy systems
- not as effective for aerobic endurance athletes
