Flashcards in Chapter 1 - Applied Anatomy And Physiology (Paper 1) Deck (166):
Where does the energy we use for muscle contractions come from?
Adenosine triphosphate (ATP)
What is Adenosine Triphosphate (ATP)?
The only useable form of energy in the body.
How do we get Adenosine Triphosphate?
The food we eat such as carbohydrates is broken down to release energy that is used to form ATP.
What does ATP consist of?
One molecule of Adenosine and three phosphates.
How is the energy from ATP released?
It is released by breaking down the bonds that hold the compound together.
What is the enzyme that breaks down Adenosine triphosphate?
What does ATPase break ATP down into?
It breaks down ATP into Adenosine di-phosphate (ADP) and an inorganic phosphate (Pi)
How does the body rebuild ATP?
It converts ADP and Pi back into ATP.
What are the three ways we can re-synthesise ATP?
1) Aerobic system
2) The ATP-PC system
3) Anaerobic glycolytic system
How are the energy systems fuelled?
Food or phosphocreatine which is found in the muscles.
What determines what energy system is used?
The type of exercise regarding the intensity, duration and whether oxygen is present.
The higher the intensity of the activity the more the individual will rely on the ... energy production
The lower the intensity and the longer the duration of the activity the more the individual will rely on the ... system
When is the aerobic system used?
When exercise is low and oxygen supply is high.
Give an example of an activity that uses the aerobic system.
What is broken down in the aerobic system?
This system breaks glucose into carbon dioxide and water which, in the presence of oxygen, which is much more efficient.
The complete oxidation of glucose can produce up to how many molecules of ATP?
Using the aerobic energy system what can also be broken down?
Fats in the form of fatty acids and proteins in the form of amino acids can be broken down. The products of fat and protein metabolism are reduced to the molecule acetyl coenzyme A that enters the Krebs cycle.
What are the three stages of the aerobic system?
2) Krebs cycle
3) Electron transport chain
A process in which glucose is converted into pyruvate to produce energy.
What is the sarcoplasm?
The fluid that surrounds the nucleus of a muscle fibre and is the site where anaerobic respiration takes place.
What is the Krebs cycle?
A series of cylindrical chemical reactions that take place using oxygen in the matrix of the mitochondria.
What happens during glycolysis? How many ATP molecules are formed?
Glycolysis is the breakdown of glucose to pyruvic acid. For every molecule of glucose undergoing glycolysis, a net of of two molecules of ATP is formed.
What is unusual about glycolysis?
It is anaerobic taking place in the sarcoplasm of the muscle cell.
Where does glycolysis occur?
In the sarcoplasm of the muscle cell.
Before the pyruvic acid produced in glycolysis can enter the next stage (Krebs cycle) what happens?
The pyruvic acid is oxidised into two acetyl groups and is then carried into Krebs cycle by coenzyme A.
What happens during the Krebs cycle?
The two acetyl groups diffuse into the matrix of the mitochondria and a complex cycle of reactions occurs. The acetyl groups combine with oxaloacetic acids, forming citric acid. Hydrogen is removed from the citric acid and the rearranged form of citric acid undergoes 'oxidative carboxylation' which simply means that carbon and hydrogen are given off. The carbon forms carbon dioxide which is transported to the lungs and breathed out and the hydrogen is taken to the electron transport chain. The reactions that occur result in the production of two molecules of ATP.
What is the electron transport chain?
Involves a series of chemical reactions in the cristae of the mitochondria where hydrogen is oxidised to water and 34 ATP are produced.
What happens in the electron transport chain?
Hydrogen is carried to the electron transport chain by hydrogen carriers. This occurs into the cristae of the mitochondria and the hydrogen splits its hydrogen ions and electrons and they are charged with potential energy. The hydrogen ions are oxidised to form water while the hydrogen electrons provide the energy to re-synthesise ATP.
What is the product of the Electron Transport Chain?
34 ATP are formed.
What is stored fat broken down into to be transported by the blood?
It is broken down into glycerol and free fatty acids.
What is beta oxidation?
It is a process that converts the fatty acids into acetyl coenzyme A, which is the entry molecule for the Krebs cycle.
What provides a higher ATP yield glucose or fatty acids?
Fatty acids which is why in long duration, low-intensity exercise, fatty acids will be the predominant energy source.
Name three advantages of the aerobic system.
- More ATP can be produced: 36 ATP
- There are no fatiguing by-products (carbon dioxide and water)
- Lots of glycogen and triglycerides stores can last for a long time.
Name two disadvantages of the aerobic system.
-This is a complicated system so cannot be used straight away. It takes a while for enough oxygen to become available to meet the demands of the activity and ensure glycogen and fatty acids are completely broken down.
-Fatty acid transportation to muscles is low and also requires 15% more oxygen to be broken down than glycogen.
What is phosphocreatine (PC)?
An energy-rich phosphate compound found in the sarcoplasm of the muscles.
What is the fuel for the ATP-PC system?
Give examples of activities that use the ATP-PC system.
Its rapid availability is important for a single maximal movement such as the long jump take-off or shot putt.
How long can PC stores be used?
How is PC replenished?
During low intensity work when oxygen is available.
How does the ATP-PC system work?
It is an anaerobic process that re-synthesises ATP when the enzyme creatine kinase detects high levels of ADP. It breaks down the phosphocreatine in the muscles to phosphate and creatine, releasing energy. This energy is then used to convert ADP to ATP in a coupled reaction.
What does anaerobic mean?
A reaction that can occur without the presence of oxygen.
What is a coupled reaction?
When energy required by one process is supplied by another process.
What is the equation that represents the breakdown of phosphocreatine?
Phosphocreatine (PC) -> Phosphate (Pi) + Creatine (C) + energy
What is the equation that represents energy is used to make ATP?
Energy -> Pi + ADP -> ATP
How many ATP molecules are produced from one phosphocreatine molecule?
1 ATP molecule
Why is the ATP-PC system not very efficient?
It is because one molecule of phosphocreatine makes 1 molecule of ATP.
Name 4 advantages of the ATP-PC system.
- ATP can be re-synthesised rapidly using the ATP-PC system.
- Phosphocreatine stores can be re-synthesised quickly (30s = 50% replenishment and 3 mins = 100%)
- There are no fatiguing by-products.
- It is possible o extend the time the ATP-PC system can be utilised through use of creatine supplementation.
Name 3 disadvantages of the ATP-PC system.
- There is only a limited supply of phosphocreatine in the muscle cell, i.e. It can only last 10 seconds.
- 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 i.e. When the intensity of the exercise is reduced).
For high intensity activity lasting less than three seconds, how will energy be provided?
Energy will be provided from just the breakdown of ATP.
What is the short-term lactate anaerobic system/anaerobic glycolytic system?
Produces high powered energy for high intensity events such as the 400m.
What determined the length the short-term lactate anaerobic system/ anaerobic glycolytic system can be used?
This depends on the fitness of the individual and how high the intensity of the exercise is.
How does the short-term lactate anaerobic system/ anaerobic glycolytic system work?
When PC stores are low, the enzyme glycogen phosphorylase is activated to break down glycogen into glucose, which is further broke down to pyruvic acid by the enzyme phosphofructokinase. This process is called anaerobic glycolysis and takes place in the sarcoplasm of the muscle cell where oxygen is not available. Since this is an anaerobic process, the pyruvic acid is then further broken down into lactic acid by the enzyme lactate dehydrogenase (LDH). During anaerobic glycolysis, energy is released to allow ATP re-synthesise.
How many ATP molecules are produced from glucose during the short-term lactate anaerobic system/ anaerobic glycolytic system?
The net result is two molecules of ATP are produced for one molecule of glucose broken down.
How long does the the short-term lactate anaerobic system/ anaerobic glycolytic system last?
Up to 3 mins but can peak at 45 seconds.
What are the key points about glycolysis?
-Breakdown of glucose to pyruvic acid.
-Produces two molecules of ATP.
-During intense exercise, pyruvic acid converted into lactic acid.
Name 3 advantages of the anaerobic glycolytic system.
-ATP can be re-synthesised quite quickly due to very few chemical reactions and lasts for longer than the ATP-PC system.
- In the presence of oxygen, lactic acid can be converted back into liver glycogen or used as a fuel through oxidation into carbon dioxide and water.
- It can be used for a sprint finish (i.e. To produce an extra burst of energy).
Name two disadvantages of the anaerobic glycolytic system.
-Lactic acid as the by-product! The accumulation of acid in the body de-natures enzymes and prevents them increasing the rate at which chemical reactions take place.
- Only a small amount of energy can be released from glycogen under anaerobic conditions (5% as opposed to 95% under aerobic conditions).
What is the energy continuum?
A term which describes the type of respiration used by physical activities. Whether it is aerobic or anaerobic respiration depends on the intensity and duration of the exercise.
Do the energy systems work independently?
No, they all contribute during all types of activities, but one of them will be the predominant energy provider.
What determines which energy system will be the predominant?
The intensity and duration of the activity.
The energy continuum is often explained in terms of threshold. Explain what this means.
The ATP-PC/anaerobic glycolytic threshold is the point at which the ATP-PC energy system is exhausted and the anaerobic glycolytic system takes over (8-10 seconds). The anaerobic glycolytic/aerobic threshold is the point at which the anaerobic glycolytic system is exhausted and the aerobic system takes over (3 mins).
Describe the ATP generation by slow twitch muscle fibre.
- The main pathway for ATP production is in the aerobic system.
- It produces the maximum amount of ATP available available from each glucose molecule (up to 36 ATP).
- Production is slow but these fibres are more endurance based so less likely to fatigue.
Describe the ATP generation of fast twitch muscle fibres.
- The main pathway for ATP production is via the lactate anaerobic glycolytic energy system (during glycolysis).
- ATP production in the absence of oxygen is not efficient - only two ATP produced per glucose molecule.
- Production of ATP this way is fast but cannot last for long as these fibres have least resistance to muscle fatigue.
What energy system is predominantly used for long periods of time at a low intensity? Explain why.
The aerobic system. This is because at low intensity exercise, the demand for oxygen can easily be met and glucose can be broken down much more efficiently when oxygen is present.
What source of food are used for energy at a low intensity?
Fats are used for energy at a low intensity, but as intensity increases there usage becomes limited because they require more oxygen than glucose in their breakdown. As soon as oxygen supplies become limited, fat use for energy drops.
Define oxygen consumption.
The amount of oxygen we use to produce ATP.
Define VO2 max.
The maximum volume of oxygen that can be taken up and utilised by the muscles per minute.
Define sub-maximal oxygen deficit.
When there is not enough oxygen available at the start of exercise to provide all the energy (ATP) aerobically.
At rest how much oxygen do we consume on average per minute?
0.3 to 0.4 litres per minute
As the intensity of of exercise increases, what happens to the amount of oxygen consumed?
The amount of oxygen consumed increases.
If the intensity of exercise continues to increase, does your oxygen consumption continue to increase too?
The oxygen consumption increases until the performer reaches maximal oxygen consumption (VO2 max)
What is the average maximal oxygen consumption per minute?
When we begin to exercise, insufficient oxygen is distributed to the tissues for all the energy to be provided aerobically. Why?
This is because it takes time for the circulatory system to respond to the increase in demand for oxygen and it also takes time for the mitochondria to adjust to the rate of aerobic respiration needed.
At the start of exercise when there is insufficient oxygen, how is energy provided?
Energy is provided anaerobically to satisfy the increase in demand for energy until the circulatory system and mitochondria can cope. (Sub-maximal oxygen deficit)
What is maximal oxygen deficit usually referred to as?
Maximal accumulated oxygen deficit (MAOD)
On a graph what is the clear difference between sub-maximal oxygen deficit and maximal accumulated oxygen deficit?
Oxygen deficit is bigger during maximal exercise as the performer is short of more oxygen at the start as they have to work more anaerobically.
What does recovery involve?
Returning the body to its pre-exercise state.
What is excess post-exercise oxygen consumption (EPOC)?
The amount of oxygen consumed during recovery above that which would have been consumed at rest during the same time.
Why is a performer breathless after exercise?
When a performer finishes exercise, oxygen consumption still remains quite high in comparison with oxygen consumption at rest. This is because extra oxygen needs to be taken in and used to try to help the performer recover.
What are the two main components to excess post-exercise oxygen consumption?
-The fast component
-The slow component
What is the fast component?
The restoration of ATP and phosphocreatine stores and the re-saturation of myoglobin with oxygen.
What does the fast component use?
Extra oxygen that is taking in during recovery.
Where does the myoglobin store oxygen?
In the sarcoplasm
What is the slow component? What are the several functions?
The slow component is the oxygen consumed during the slow replenishment stage. It has several function; removal of lactic acid, maintenance of breathing and heart rates, glycogen replenishment and increase in body temperature.
How can lactic acid be removed?
-When oxygen is present, lactic acid can be converted back into pyruvate and oxidised into carbon dioxide and water in the inactive muscles and organs. This can be used by the muscles as an energy source.
-Transported in the blood to the liver where it is converted to blood glucose and glycogen (Cori cycle).
-Converted into protein
-Removed in sweat and urine
What is the cori cycle?
The process where lactic acid is transported in the blood to the liver where it is converted to blood glucose and glycogen.
Why can a cool-down performed directly after exercise aid the removal of lactic acid?
The majority of lactic acid can be oxidised in mitochondria so performing a cool-down can accelerate its removal. This is because exercise keeps the metabolic rate of muscles high and keeps capillaries dilated, which means oxygen can be flushed through, removing the accumulated lactic acid.
How does the slow component aid the maintenance of breathing and heart rates?
Main ting breathing and heart rates requires extra oxygen to provide the energy needed for the respiratory and heart muscles. This assists recovery as the extra oxygen is used to replenish ATP and phosphocreatine stores, re-saturate the myoglobin and remove lactic acid, therefore returning the body back to its pre-exercise state.
How does the slow component aid glycogen replenishment?
Glycogen is the main energy provider and, as it is the fuel for both the aerobic system and anaerobic glycolytic system, it will be depleted during exercise. The replacement of glycogen stores depends on the type of exercise undertaken and when and how munch carbohydrate is consumed following exercise. It may take several days to complete the restoration of glycogen after a marathon, but in less than a hour after a high duration, short intensity exercise, a significant amount of glycogen can be restored as lactic acid is converted back to blood glucose and glycogen in the liver via the cori cycle.
Eating a meal high in .... will accelerate glycogen restoration.
What are the two nutritional windows for optimal recovery after exercise?
- 30 minutes after exercise where both carbohydrates and proteins should be consumed in a 3:1 or 4:1 ratio.
- 1-3hrs after exercise and a meal of high protein, carbohydrate and healthy fat should be consumed.
Why is a combination of both carbohydrates and protein important after exercise?
The combination of carbohydrates and protein helps the body to re-synthesise muscle glycogen much more efficiently than just consuming carbohydrates on their own.
How does the slow component increase the body temperature? Why?
Extra oxygen from the slow component of the excess post-exercise oxygen consumption (EPOC) is used to fuel the increase the body temperature. This is needed because when the temperature remains high, respiratory rates will also remain high and this will help the performer take in more oxygen during recovery.
What is the difference between lactic acid and lactate?
Lactic acid is produced as a by-product by the anaerobic glycolytic system as a result of glycolysis. Lactate however is a salt formed when the H+ ions are released from the lactic acid and the remaining bit of the acid joins Na+ ions. Glycolysis produces lactic acid which immediately disassociates and lactate is formed.
When the intensity of exercise is higher, the more .... is produced?
How does lactate form?
Lactic acid releases H+ ions. The remaining compound combines with sodium ions (Na+) or potassium ions (K+) to form the salt lactate.
What increases the acidity within the muscles?
The presence of hydrogen ions.
As lactate accumulates in the muscles, more ...... are present.
What causes muscle fatigue?
When lactate accumulates in the muscles it slows down the enzyme activity which affects the breakdown of glycogen.
How can lactate be measured?
The lactate produced in the muscles diffuses into the blood and blood lactate can be measured.
What is the lactate threshold?
The point during exercise at which lactic acid quickly accumulates in the blood.
What is the crossing over from working aerobically to anaerobically known as?
What is OBLA?
Onset blood lactate accumulation and this is the point when lactate levels go above 4 millimoles per litre.
How many millimoles of lactate are present in the blood during rest?
1-2 millimoles per litre
What does OBLA give an indication of?
Measuring OBLA gives an indication of endurance capacity. Some individuals can work at higher levels of intensity than others before OBLA and can delay when the threshold occurs.
How is lactate threshold expressed?
It is expressed as a percentage of VO2 max.
How does the lactate threshold change as fitness level changes?
As fitness increases, the lactate threshold becomes delayed. The fitter we are, the higher our lactate threshold as a percentage of our VO2 max and hence the harder we can work.
Compare and average performers lactate threshold of their VO2 max to an elite performers.
Average performers may have a lactate threshold of 50-60% of their VO2 max, whereas elite performers may have a lactate threshold that is 70,80,90% of their VO2 max.
Does training have a large impact on VO2 max?
No, VO2 max is largely genetically determined and training only has a limited effect.
What is a good practical example to illustrate the OBLA? Why?
The multi-stage fitness test. As the test becomes more and more demanding because of the reduced time to complete each shuttle, the performer eventually reaches a point where energy cannot be provided aerobically. This means the performer has to use the anaerobic system to re-synthesise ATP. Levels of lactate produced in the muscles increases until eventually muscle fatigue occurs and the performer slows down or is no longer able to keep up with the bleep.
What are the factors that affect the rate of lactate accumulation?
-Muscle fibre type
-Rate of blood lactate removal
-The respiratory exchange ratio
-Fitness of the performer
How does the intensity of an exercise affect the rate of lactate accumulation?
The higher the exercise intensity, the greater the demand for energy (ATP) and the faster OBLA occurs. Fast twitch fibres are used for high intensity exercise and can only maintain their workload with the use of glycogen as a fuel. When glycogen is broken down in the absence of oxygen into pyruvic acid, lactic acid is formed.
How does the muscle fibre type affect the rate of lactate accumulation?
Slow twitch fibres produce less lactate than fast twitch fibres. When slow twitch fibres use glycogen as a fuel, due to the presence of oxygen, the glycogen can be broken down much more effectively and with little lactate production.
How does the rate of lactate removal affect the rate of lactate accumulation?
If the rate of lactate removal is equivalent to the rate of lactate production, then the concentration of blood lactate remains constant. If lactate production increases, the 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 respiratory exchange ratio is the ratio of carbon dioxide produced compared to oxygen consumed. As this ratio has a value close to 1:0, glycogen becomes the preferred fuel and there is a greater chance of the accumulation of lactate.
How does the fitness of the performer affect the rate of lactate accumulation?
A person who trains regularly will be in a better position to delay the OBLA as adaptations occur to trained muscles. Increased numbers of mitochondria and myoglobin, together with an increase in the capillary density, improve the capacity for aerobic respiration and therefore avoid the use of the lactate anaerobic system.
What types of people will have better anaerobic endurance?
Elite sprinters and power athletes
Why do elite sprinters and power athletes have a better anaerobic endurance?
This is because their body has adapted to cope with high levels of lactate. In addition, through a process called buffering, they will be able to increase the rate of lactate removal and consequently have lower lactate levels.
What is buffering?
A process which aids the removal of lactate and maintains acidity levels in the blood and muscle.
What does buffering allow athletes to do?
It allows the athletes to be able to work at higher intensities for longer before fatigue sets in. As well as being able to tolerate higher levels of lactate.
What adaptive responses will occur to athletes producing lots of lactate?
There will be a greater number and size of mitochondria and the associated oxidative enzymes, increased capillary density and more myoglobin.
What physiological factors affect VO2 max?
-Increased maximum cardiac output
-Increased stroke volume/ ejection fraction/ cardiac hypertrophy
-Greater heart rate range
-Less oxygen being used for heart muscle so more available to the muscles
-Increased levels of haemoglobin and red blood cell count
-Increased stores of glycogen and triglycerides
-Increased myoglobin content
-Increased capillarisation around the muscles
-Increased number and size of mitochondria
-Increased surface area of alveoli
-Increased lactate tolerance
What are the lifestyle factors that affect VO2 max?
Can all reduce VO2 max values
How can training affect VO2 max?
VO2 max can be improved by up to 10-20% following a period of aerobic training (continuous, fartlek and aerobic interval)
How can genetics affect VO2 max?
Inherited factors of physiology limit possible improvements.
How can differences in age affect our VO2 max?
As we get older our VO2 max declines as our body systems become less efficient.
How does gender affect VO2 max?
Males generally have approx. 20% higher VO2 max than women.
How does body composition affect VO2 max?
A higher percentage of body fat decreases VO2 max.
What is calorimetry?
The calculation of heat in physical changes and chemical reactions.
What is indirect calorimetry?
Measures the production of CO2 and/or the consumption of O2.
What are the measurement of energy expenditure?
-VO2 max test
-Respiratory exchange ratio
How does indirect calorimetry measure energy expenditure?
It is a technique that provides an accurate estimate of energy expenditure through gas exchange.
By calculating the gas volumes from indirect calorimetry also enables us to?
Find out the main substrate being used (fat or carbohydrate)
What is lactate sampling?
It involves taking a tiny blood sample and a handheld device analyses the blood and indicates how much lactate is present.
What can lactate sampling be used for?
Measuring exercise intensity
Using lactate sampling how do you determine the fitness of an athlete?
The higher the exercise intensity at which the lactate threshold occurs, the fitter the athlete is considered to be.
How can lactate sampling be used to see improvements in athletes fitness have occurred?
Regular lactate testing provides a comparison form which the coach and performer can see whether improvement has occurred. If test results show a lower lactate level at the same intensity of exercise, this should indicate that the performer has an increased peak speed/power, increased time to exhaustion, improved recovery heart rate and finally a higher lactate threshold.
How is VO2 max tested accurately in sport science labs?
Through the use of direct gas analysis and the use of either a treadmill, cycle ergometer or rowing machine. For example, an individual runs on a treadmill to exhaustion while the air that is expired is calculated by computer software. The volume and concentration of oxygen in expired air is then measured and compared with the percentage of oxygen that is in the atmospheric air to see how much oxygen has been used during the task.
What is direct gas analysis?
Measures the concentration of oxygen that is inspired and the concentration of carbon dioxide that is expired.
What is a cycle ergometer?
A stationary bike that measures how much work is being performed.
What is the respiratory exchange ratio (RER)?
The ratio of carbon dioxide produced compared to oxygen consumed.
What information does the Respiratory exchange ratio provide? Why?
It provides information on the fuel usage during exercise. Energy sources such as carbohydrates, fats and protein can all be oxidised to produce energy. For a certain volume of oxygen, the energy released will depend upon the energy source. Calculating the Respiratory exchange ratio will determine which of these energy sources is being oxidised and hence whether the performer is working aerobically or anaerobically.
How is the Respiratory Exchange ratio calculated?
RER = Carbon dioxide expired per minute (VCO2) / Oxygen consumed per minute
What does a RER value close to 1 mean?
Performer is using carbohydrates
What does a RER value of approx 0.7 mean?
The performer is using fats
What does an RER greater than 1 mean?
Anaerobic respiration so more CO2 being produced than O2 consumed.
What is altitude training?
Usually done at 2500 m+ above sea level where the partial pressure of oxygen is low.
Explain how altitude training impacts the energy systems?
The partial pressure of O2 is lower at higher altitudes. Therefore there is a reduction in the diffusion gradient of oxygen between the air and the lungs and between the alveoli and the blood. This means that not as much oxygen diffuses into the blood so haemoglobin is not as fully saturated with oxygen, which results in the lower O2 carrying capacity of the blood. As less O2 is therefore delivered to the working muscles, there is a reduction in aerobic performance and VO2 max and a quicker onset of anaerobic respiration.
What are the disadvantages of altitude training?
-When the athletes first experiences altitude, it is very difficult to train at the same intensity due to the reduction in the partial pressure of oxygen so there can be a loss of fitness or detraining.
-Altitude sickness is a possibility, which can shave a detrimental effect on the training programme.
-The benefits gained from the altitude training can be lost very quickly on return to sea level and the body can only produce a limited amount of EPO.
-Living away from home can also result in psychological problems such as homesickness.
Name four specialist training g methods that affect the energy systems.
-High intensity interval training
-Speed, agility, quickness (SAQ)
What are the four main variables of high intensity interval training?
-The duration of the work interval
-The intensity or speed of the work interval
-The duration of the recovery interval
-The number of work intervals and recovery intervals
What is high intensity interval training?
High intensity interval training involves short intervals of maximum intensity exercise followed by a recovery interval of low to moderate intensity exercise.
Which aerobic/anaerobic is used during high intensity interval training?
Both. The work interval is anaerobic and the rest interval is aerobic.
What are the benefits of high intensity interval training?
By pushing your body to the max during the work interval increases the amount of calories you burn as it takes longer to recover from each work session. HIIT therefore improves fat burning potential, glucose metabolism and both aerobic and anaerobic endurance.
What are the different variations of HIIT?
-Different number of high intensity work intervals and low intensity recovery intervals.
-Different lengths of time for the work and recovery intervals
-Different exercise intensity for the recovery interval (low or medium intensity)
What is plyometrics?
Involves repeated rapid stretching and contracting of muscles to increase muscle power.
What does plyometrics training involve?
High intensity explosive activities including hopping, bounding, depth jumping and medicine ball work
What is the basis of plyometrics?
It works on the concept that muscles can generate more force if they have been previously been stretched.
What are the three phases of the stretch shortening cycle?
-Eccentric phase or pre-loading/pre-stretching phase. On landing, the muscle performs an eccentric contraction where it lengthens under tension.
-Amortisation phase is next and is the time between the eccentric and concentric muscle contraction. The time needs to be as short as possible so the energy stored from the eccentric contraction is not lost. When an eccentric contraction occurs, a lot of the energy required to stretch or lengthen the muscle is lost as heat but some of the energy can be stored and is then available for the subsequent concentric contraction.
-Concentric muscle contraction phase uses the stored energy to increase the force of the contraction.
What is speed?
Speed refers to how fast a person can move over a specified distance or how quickly a body part can be put into motion.
What is agility?
The ability to move and position the body quickly and effectively while under control.
What does good agility require?
A combination of speed, co-ordination, balance and flexibility.
What is Speed, agility, quickness training?
This is a type of training that aims to improve multi-directional movement through developing neuromuscular system.
How is the energy provided during SAQ?
Anaerobically as they are performed with maximum force at high speed.