Energy Systems (P1) Flashcards
What does ATP stand for and what is the definition?
Adenosine triphosphate is the only usable form of energy in the body.
How is ATP used to for energy?
The enzyme ATPase is used to break down ATP leaving ADP and an inorganic phosphate. This process releases energy.
What three energy systems help to convert fuel into energy?
- ATP-PC System
- Anaerobic Glycolytic System
- The Aerobic System
What two fuels fuel chemical reaction to resynthesise ATP?
Food and phosphocreatine (PC)
What is phosphocreatine?
An energy rich phosphate found in the sarcoplasm of the muscles
What fuel is used by the ATP-PC system?
PC
How does ATP-PC work to provide energy?
The system resythesises ATP when the enzyme creatine kinase detects high levels of ADP. It breaks down PC in the muscles to phosphate and creatine which releases energy. The energy is then used to convert ADP to ATP in a coupled reaction.
What is a coupled reaction?
When energy required by one process is supplied by another process.
What are the advantages of the ATP-PC system?
.ATP can be re-synthesised quickly
.PC stores can be replenished quickly- 50%-30s, 100%-3 minutes
.no fatiguing by-products
. length of the system can be increased by creatine supplementation
What are the disadvantages of the ATP-PC system?
.limited supply of PC (5-8 seconds worth)
. Only one mole of ATP can be re-synthesised for every mole of PC
. PC re-synthesis can only take place in the presence of oxygen
what does the duration of the anaerobic glycolytic system depend on?
The fitness of the individual and the intensity of the activity.
What fuel is used and broken down in the anaerobic glycolytic system and where does it come from?
Glucose- supplied form the digestion of carbohydrates and stored in muscles and liver as glycogen.
How does the anaerobic glycolytic system work to provide energy?
.enzyme glycogen phosphorylase breaks down glycogen to glucose
. enzyme phosphofructokinase breaks the glucose to pyruvic acid
. enzyme lactate dehydrogenase breaks down pyruvic acid into lactic acid
Through this process energy is released meaning two molecules of ATP is re-synthesised for one molecule of glucose broken down
What is the name of the process that occurs in the anaerobic glycolytic energy system?
Anaerobic glycolysis and takes place in the sarcoplasm of the muscle cell
What are the advantages of the anaerobic glycolytic system?
. quick re-synthesis of ATP and lasts longer than ATP-PC system
. presence of oxygen can allow lactic acid to be converted back into liver glycogen or used converted into co2 and h2o and used as a fuel
. used for sprint finish
What are the disadvantages of the anaerobic glycolytic system?
. lactic acid as a by-product
. small amount of energy released from glycogen under anaerobic conditions
When is the aerobic system the preferred energy system?
When exercise intensity is low and oxygen supply is high
What two sources of energy can the aerobic system break down for energy?
Glucose and fat
What are the three stages of the aerobic system?
1) Glycolysis/Beta oxidation
2) Krebs cycle
3) Electron transport chain
What is glycolysis in the aerobic system?
A process by which glucose is converted to pyruvate acid to produce two molecules of ATP for every molecule of glucose undergoing glycolysis. Takes place in the sarcoplasm of the muscle cell
How does the pyruvic acid from glycolysis enter the krebs cycle?
oxidised into two acetyl groups and carried by the coenzyme A
What is beta oxidation?
Stored fat is broken down into glycerol and free fatty acids. The fatty acids undergo beta oxidation where they are converted to acetyl coenzyme A in order to enter the krebs cycle. More ATP can be produced than glycolysis.
What is the krebs cycle?
The acetyle groups combine with oxaloacetic acid forming citric acid which undergoes oxidative carboxylation which gives off hydrogen and carbon. The carbon forms co2 and is breathed out and hydrogen is taken to the electron transport chain. 2 ATP is produced.
What is the electron transport chain?
Involves a series of chemical reactions in the cristae of the mitochondria where hydrogen splits into ions and electrons. The ions are oxidised to form water and the electrons provide the energy to re synthesise ATP. 34 ATP are produced.
What are the advantages of the aerobic system?
.More ATP produced- 36
. no fatiguing by products
. lots of glycogen and triglyceride stores so exercise can last for a long time
What are the disadvantages of the aerobic system?
. complicated system so can’t be used straight away
What is the energy continuum?
A term which describes the type of respiration used by physical activities. The energy system used depends on the activities duration, intensity, fitness of the individual, presence or lack of oxygen
What is the duration of activities for each energy system?
<10 =ATP-PC
8-90 secs= ATP-PC and anaerobic glycolytic
3+ mins= aerobic
What is the ATP generation of the slow twitch fibres?
. Mainly aerobic system
. produces max ATP
. production is slow but fatigue is unlikely
What is the ATP generation of the fast twitch fibres?
Mainly anaerobic systems
. ATP production is not efficient
. ATP production is fast but doesnt last as long as the muscle fibres are less resistant to fatigue
What is oxygen consumption?
The amount of oxygen we use to produce ATP
What is VO2 max?
The maximum volume of oxygen that can be taken up by the muscles per minute.
What is the sub-maximal oxygen deficit?
When there is not enough oxygen available at the start of exercise to provide all the energy aerobically.
What is MAOD?
Maximal accumulated oxygen defecit and gives an indication of anaerobic capacity
What is EPOC?
Excess Post Exercise Oxygen Consumption. The amount of oxygen consumed during recovery above that which would have been consumed at rest during the same time.
What are the two components of EPOC?
fast and slow
What is the fast component of EPOC?
The restoration of PC and ATP stores and the re-saturation of myoglobin and oxygen.
During the fast component of EPOC, how long do PC stores take to replenish and how much oxygen is consumed?
100%- 3minutes
50%- 30 seconds
3 litres
During the fast component of EPOC, how long does it take to replenish myoglobin stores and how much oxygen is consumed?
up to 2 minutes
0.5 litres
What is lactate accumulation?
When lactic acid builds up in the body and then breaks down giving off hydrogen ions and the remaining compound combines with sodium or potassium ions to form salt lactate.
How affect does the accumulation of lactate have?
Denatures enzymes affecting the break down of glycogen causing muscle fatigue
What is the lactate threshold?
The point during exercise at which lactic acid quickly accumulates in the blood
What is OBLA?
(Onset Blood Lactate Accumulation) The point when lactate levels go above 4 millimoles per litre
What is the relationship between lactate threshold and the VO2 max?
Lactate threshold is a percentage of VO2 max. Average performers have lactate threshold of 50-60% of VO2 max. elite performers=70,80,90% of VO2 max. The fitter we are the higher the lactate threshold % of our VO2 max.
What are the factors that affect lactate accumulation?
Exercise intensity Muscle fibre type Rate of blood lactate removal The respiratory exchange ratio Fitness of the performer
What physiological factors increase an individuals VO2 max?
Increased cardiac output Increased stroke volume/ejection fraction greater heart rate range increased levels of haemoglobin increased stores of glycogen increased lactate tolerance
What is lactate sampling?
Lactate sampling involves involves taking a tiny blood sample on a handheld device which analyses the blood and indicates how much lactate is in it.
What are the four functions of the slow component of EPOC?
. Removal of lactic acid
. Maintenance of breathing and heart rate
. Glycogen replenishment
. Increase in body temperature
How is lactic acid removed in the slow component of EPOC?
. Full recovery may take up to an hour or longer
. When oxygen is present, lactic acid can be converted back into pyruvate and oxidised into CO2 and H2O
. Transported in the blood to the liver where it is converted to blood glucose and glycogen (the Cori cycle)
. Converted into protein
. Removed in sweat and urine
Explain the maintenance of breathing and heart rates in the slow component?
This assists recovery as the extra oxygen is used to to replenish ATP and PC stores an other recovery parts. This helps return the body to pre-exercise state.
Explain the glycogen replenishment in the slow component in the slow component?
. May take several days to fully recover glycogen stores after a maraphon
. Cori cycle converts lactic acid back to blood glucose and glycogen in the liver
. In the first 30 minutes after exercise carbohydrates and protein should be consumed in a 3/4:1 ratio.
Explain the increase in body temperature in the slow component?
When temperatures remains high, respiratory rates will also remain high and help the performer take in more oxygen during recovery.
What factors affect the rate of lactate accumulation?
. Exercise intensity . Muscle fibre types . Rate of blood lactate removal . The respiratory exchange ratio . Fitness of the performer
How does exercise intensity affect the rate of lactate accumulation?
. the higher the exercise intensity, the greater the demand for energy (ATP) and the faster OBLA occurs
How does muscle fibre type affect the rate of lactate accumulation?
Slow twitch fibres produce less lactate than fast twitch fibres.
How does the rate of blood lactate removal affect the rate of lactate accumulation?
If lactate production is greater than lactate removal , then lactate will start to accumulate in the blood until OBLA is reached.
How does the respiratory exchange ratio affect the rate of lactate accumulation?
The ratio of carbon dioxide produced compared to oxygen consumed. When the ratio has a value greater than 1:0, there is anaerobic respiration and there is a greater chance of the accumulation of lactate because there is more CO2 produced compared to O2 consumed.
How does the fitness of the performer affect the rate of lactate accumulation?
A person who trains regularly will be in a better at delaying OBLA because of the adapted muscles. Increased number of mitochondria and myoglobin and an increase in capillary density. This improves the capacity
How does training affect VO2 max?
Can be improved by 10-20% following a period of aerobic training
How does genetics affect VO2 max?
inherited factors may limit possible improvements
How does differences in age affect VO2 max?
Age decreases vo2 max
How does gender affect VO2 max?
Men have 20% higher vo2 max
How does body composition affect VO2 max?
Higher % of body fat decreases VO2 max
How does lifestyle affect VO2 max?
Smoking, sedentary lifestyle and poor diet will all reduce VO2 max levels
What can be used to measure energy expenditure?
Indirect calorimetry, lactate sampling, VO2 max test, respiratory exchange ratio (RER)
What is indirect calorimetry?
Measurement of energy expenditure through gaseous exchange. It measures how much CO2 is produced and how much oxygen is consumed at rest and during aerobic exercise. Also indicates VO2 max.
What is lactate sampling?
. Involves taking a tiny blood sample and a handheld device analyses the blood and indicates how much lactate is present.
. Can measure the exercise intensity
. Can give an idea on the level of fitness
. Allows the performer to choose relevant training zones
. Can show improvements
What is the VO2 max test?
. Known as direct gas analysis
. Measures the concentration of oxygen that is inspired and the concentration of carbon dioxide expired.
. Shows how much oxygen is used during performance
What is the respiratory exchange ratio test?
. Ratio of carbon dioxide produced compared to oxygen consumed and used to measure exercise intensity. . . .
. Provides information about fuel usage during exerciser
. The RER determines which energy source is being oxidised and this infers whether the performer is working aerobically or anaerobically
How is HIIT training made specific to an event?
. duration of the work interval
. intensity of the work interval
. duration of the recovery interval
. the number of work and recovery intervals
What is HIIT training?
. Can be used for aerobic and anaerobic training
. Form of training in which periods of work are interspersed with recovery periods
. work is anaerobic and the rest period is aerobic
What is plyometrics?
. Involves repeated rapid stretching and contracting of muscles to increase muscle power.
. when there is an eccentric contraction followed by a concentric contraction, the force generated can be dramatically increased
What are the three stages of plyometrics (stretch shortening cycle)?
. Eccentric phase
. Amortisation phase- time between eccentric and concentric contractions which is short and stores energy
. Concentric phase- muscle uses the stored energy to increase the force of contraction
What values from a RER test shows whether a performer is using carbohydrates, fats or working anaerobically?
. close to 1=carbohydrates
. 0.7= fats
. >1=anaerobic respiration
What is the definition of altitude training?
Usually done at 2500+m above sea level where the partial pressure of oxygen is lower
How does altitude training work?
. Smaller diffusion gradient at high altitudes
. less diffusion of oxygen into the blood so haemoglobin is not as fully saturated
. more haemoglobin is required as less is carried in each one
. less oxygen delivered to muscles=reduction in aerobic capacity
. when returning to sea level, the greater number of haemoglobin fill with oxygen so there is greater oxygen delivery to muscles than before altitude training
What are the advantages of altitude training?
. increase in aerobic performance at sea level
. acclimatisation to lower partial pressure of oxygen e.g England
What are the disadvantages of altitude training?
. can be a loss fitness at first due to lower training intensities
. altitude sickness can disrupt training programmes
. benefits can be lost quickly at sea level
. homelessness
What are two example of plyometrics?
. leg strength- line of benches, boxes and hurdles to be jumped
. arm strength- clap press ups
What is SAQ (speed, agility, quickness) training? and give an example
. Type of anaerobic training that aims to improve aims to improve ,multi directional movement. e.g zig zag runs, foot ladders
