Energy systems

the only usable form of energy in the body

it breaks down ATP into ADP and PI
ADP + Pi + Energy

- The aerobic system
- The ATP-PC system
- The anaerobic glycolitic system

when intensity is low and oxygen supply is high, the aerobic system is the perfered energy pathway. the aerobic system breaks glucose into carbon dioxide and water, which is more efficient in the presence of oxygen

38

fats are broken down into fatty acids and proteins into amino acids. the products of fats and protein metabolism are reduced to produce acetyl-coA that enters the krebs cycle

- glycolysis - krebs cycle - electron transport chain

takes place in the sarcoplasm, it breaks glucose into pyruvic acid. net ATP 2. before pyruvic acid can enter the krebs cycle its oxidised in to 2 acetyl groups and then carried in by coA

2 acetyl groups diffuse into the matrix of the mitochondria. a complete cycle of reactions occur. acetyl combines with oxaloacetic acid, forming citric acid. hydrogen is removed from citric acid and rearranged form undergoes 'oxidative carboxylation' meaning carbon and hydrogen are givern off. carbon forms c02 and is taken to the lungs and breathed out and hydrogen is taken to the electron transport chain. 2ATP produced

hydrogen is carried hereby hydrogen carriers. occurs in the cristae of mitochondria. hydrogen splits into hydrogen ions and are charged with potential energy. H ions are oxidised to form water why the hydrogen electrons provide energy to resynthesise ATP. 34 ATP are formed

stored fat undergoes beta oxidation, where they are converted into acetyl coA which is the entry molecule for the krebs cycle.

- 36 more ATP can be produced. No fatiguing biproducts. lots of glycogen and triglycceride stores, so exercise can last for a long time

- complecated system so cant be used straight away. it takes a while for enough oxygen to become avalible to meet the demand of activity and ensure glycogen and fatty acids are broken down. - Fatty acid transportation to the muscles is low and also requires 15% more oxygen to be broken down than glycogen

energy system using phosphocreatine as its fule. PC can be broken down quickly and is easy to release energy to resynthesise ATP. rapid avalibilty is good for a simple maximal movement e.g shot put. but the disadvantage is that stores are limited as theres only enough PC stores to last 5-8 secs, and can only be replenished when oxygen is avalible

Anaerobic process and resynthesis ATP when the enzyme creatine kinase detects high levels of ADP. PC-->Pi+C+energy. this energy is then used to convert ADP to ATP in a coupled reaction: Energy-->+Pi+ADP-->ATP

when energy required by one process is supplied by another process

theres enough energy released to create one molecule of ATP this.

- ATP can be used re-synthesised rapidly using the ATP-PC system. -PC stores can be resynthesised quickly (30s=50% 3min=100%). - no fatiguing biproducts. -its possible to extend the time the ATP-PC system can be utilised through the use of creatine suppliment

-there is only a limited supply PC in the muscle cells. -only one molecule of ATP can be resynthasised for every mole of PC. -PC re-synthesis can only take place in the presence of oxygen

produces high powered energy for high intensity effort events e.g 400m

high intensity, longer exercise than the ATP-PC system does

it lasts up to 2-3 minutes at a reduced intensity and is dependent on the fitness of the individual, and the intensity of the exercise. working flat out of exaustion will mean the system lasts alot shorter time as the demand for energy is high

the breakdown of the fuel glucose

When the PC stores are low, glycogen phosphorylase is activated
to break down glycogen into glucose, which is then further broken down to
pyruvic acid by the phosphofructokinase. This 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,

- ATP can be resynthesised quickly and it lasts longer than the ATP-PC system. - in the presence of oxygen, lactic acid can be converted back into liver glycogen or used as a fule through oxidation into co2 and h2o. - it can be used for a sprint finish (extra burst of energy)

- lactic acid is a bi-product. - only a small amount of energy can be released from glycogen under anaerobic conditions (5% as opposed to 95%)

a term which describes they type of respiration used by a physical activity. whether its aerobic or anaaerobic depends on the intensity and duration.

- main pathway for ATP production is in the aerobic system. - produces the maximum amount of ATP avalible from each glucose molecule (up to 36 ATP). -production is slow but these fibers are more endurance based so are less likey to fatigue.

- main path is via the lactate anaerobic energy system. -ATP production in the absence of oxygen isnt efficient. -production of ATP is fact but cant last long as they will fatigue

rest 0.3-0.4l. during exercise 3-6l

when theres not enough oxygen avalible at the start of exercise to provide all the energy aerobically

the amount of oxygen consumed during recovery above that which would have been consumed at rest during the same time

Fast component and slow component

restoration of ATP and phosphocreatine stores and the re-saturation of myoglobin with oxygen

oxygen consumed during this stage has several functions: - removal of lactic acid, -maintanence of breathing and heart rates, glycogen replenishment, increase in body temperature

lactic acid can be removed in the following ways: - in the presence of oxygen lactic acid can be converted back into pyruvate and oxidised into c02 +water, eventaully used for energy. -transported i the blood to the liver where it is converted to blood glucose and glycogen (cori cycle). -converted into protein. -removed in sweat and urine. Most lactic acid can be oxidised in the mitochondria, so a cool down can accelerate its removal as the boy is flushed with oxygen rich blood

maintaining BR and HR requires extra oxygen to provide energy needed for respiritory and heart muscles. assists recovery as extra oxygen is used to replenish ATP and PC stores, resaturate myoglobi and remove lactic acid, returning the body to pre-exercised state

Glycogen replenishment depends on type of exercise and how much carbohydrate is consumed after exercise. it may take several days to complete the restoration of glycogen after a marathon, but after half an hour a significant amount is restored as lactic acid is converted to blood glucose and glycogen via the cori cycle. eating a high carb meal will accelerate restoration .

when temp remains high respiritory rate remains high so willhelp performer take in more oxygen during recovery. extra oxygen is needed to fule this increased temp until the body returns to normal.

lactic acid breaks down creating lactate. as lactate accumulates, more H ions are present, this increases acidity. this increase in acidity denatures enzymes. glycogen cant be broken down as effectively and fatigue sets in. Lactate moves from the muscle to blood. blood lactate can be measured

the point when lactate levels go above 4 milimoles per liter

the point that lactic acid quickly accumulates in the blood during exercise

a percentage of VO2 max

as fitness increases the lactate threshold becomes delayed.

average 50-60% of their vo2 max and elite is 70, 80 or sometimes 90 % of their vo2 max, training has limited effect on vo2 max as its mainly genetic

the fitter we are the higher the lactate threshold

exercise intensity, muscle fiber type, rate of blood lactate removal, the respiritory exchange ratio, and the fitness of the performer

the higher the intensity of exercise, the greater the demand for atp and so the faster obla occurs

slow twitch muscle fibers produce less lactate than fast twitch. when slow twitch muscle fibers use glycogen as a fule, due to the presence of oxygen, the glycogen can be broken down much more effectivley and with little lactate production

rate of lactate removal is equivilent to the rate of lactate production, then the concentration of lactate in the blood is remains constant. If lactate production increases, then lactate will start to accumulate in the blood until obla is reached

the ratio of carbon dioxide produced to oxygen consumed. as the the ratio has a value close to 1:0, glycogen becomes perfered fule and there is a greater change of the accumulation of lactate

a person who trains regularly will be in a better position to delay obla, increased myoglobin and mitochondria, together with an increased capillary density, improve the capacity for aerobic respiration and so avoid the use of lactate anaerobic system

elite sprinters and power atheletes will have much better anaerobic endurance, as the body has adapted to cope with higher levels of lactate. also through buffering they will be able to increase the rate of lactate removal and so they will have lower lactate levels. this means that athletes will be able to work at higher intensities for longer before fatigue sets in.

buffering is a process which aids the removal of lactate and maintains acidity levels in the blood and muscle

physiological, lifestyle, training, genetics, gender, body composition, and differences in age

increased: max CO, greater HR range, less oxygen being used by the heart muscle, so more avalible to the muscles

smoking, sedentry lifestyles, poor diet and fitness. all can reduce VO2 max

can be improved by upto 20% following a period of aerobic training

inherited factors of physiology limit possible improvement

men have aprox 20% higher than women

a higher percentage of body fat decreased VO2 max

as we get older our VO2 max declines as our body systems become less efficient

indirect calorimetry, lactate sampling, VO2 max text and Respiritory Exchange Ratio (RER)

its a technique that provides an accurate estimate of energy expediture through gas exchange

measures the production of CO2 and/ or the consumption of O2. it measures how much carbon dioxide is produced and how much is produced both at rest and during aerobic exercise.

calculating the gas volumes also enables us to find out the main substance being used (fat or carbohydrates). the test is very reliable as it give a precise calculation of VO2 and VO2 max

lactate sampling involves taking a tiney blood sample and a handheld device analyses the blood and indicates how much lactate is present. it is accurate and objective. it can also be used to measure exercise intensity. the higher the exercise intensity that lactate threshold occurs, the fitter the performer is thought to be.

the performer has an increase in peak power/speed, an increased time to exaustion, improved recovery heart rate and a higher lactate threshold.

multi stage fitness tests including:bleep test, cooper run, harvard step test. these results get compared against a standardised resuls table, however they only give an indication of VO2 max. sports scientists use more valid and reliale including direct gas analysis and cycle ergometer

the ratio of carbon dioxide produced compared to oxygen consumed

fule usage during exercise. energy stores such as carbohydrates, fats and proteincan all be oxidised to produce energy. calculation the RER will indicate which of these is being oxidised to produce energy, and hence wether the performer is respiering aerobically and anaerobically

RER = carbon dioxide expired per minute (VCO2) / oxygen consumed per minute (Vo2)

A RER close to 1 = performer is using carbohydrates
A RER aprox 0.7 = a performer is using fats
A RER greater than 1 = anaerobic respiration

Altitude training, HIIT, Speed, agility, quickness, and plyometrics

typically completed at 2500+ above sea level where the partial pressure of oxygen is lower.

the partial pressure of oxygen drops, so there is a Reduced diffusion gradient between the air and the lungs and between the alveoli and the blood. so the haemoglobin isnt fully saturated with oxygen, resulting in the blood having a lower O2 carrying capacity. so less O2 is delivered to the working muscles, aerobic performance and VO2 max is reduced and there is a quicker onset of anaerobic respiration

many performance benifits. it is also completed to acclimatise players to a lower level of oxygen avalibility in the atmosphere e.g if they are going to performe in countries with low oxygen levels like south africa

- when an athlete first experiences altitude it can be difficult to train at the same intensity due to the reduction in partial pressure.
-also altitude sickness can be detrimental.
-benifits gained from altitude training can be lost very quickly once returned to sea level, and the body can only produce a limited abount of EPO
-finally, living away from home can cause homesickness

High intensity interval training
it can be used for both aerobic and anaerobic training
its a form of training in which periods of work are broken up by periods of recovery

-duration of work interval
-intensity/speed of the work interval
-duration of the recovery interval
-number of work intervals and recovery

short intervals of maximum intensity exercise followed by a recovery period of low intensity exercise. the work interval in anaerobic and the rest interval is aerobic

fat burning potential, glucose metabolism, and both aerobic and anaerobic indurance

-different numbers of high intensity work intervals and low intensity recovery intervals.
-different lengths of time for work and recovery intervals
-different exercise intensity for the recovery interval

training which uses high intensity explosive activities such as hopping, bounding, depth jumping, and medicine ball work
it uses fast twitch fibers

if a greater anaerobic capacity is necessary e.g speed for 100m, or power for long jump then p

muscles can generate more force if they have previously been streached. if the eccentric contraction occurs first, followed by the concentric contraction, then the force generated can be dramatically increased. this is called the streach shortening cycle

eccentric phase/ preloading phase/ prestreaching phase
Amortisation phase
concentric or muscle contraction phase

upon landing the muscle performs an eccentric contraction where it lengthens under tension

the time between the eccentric and concentric phase. this time needs to be as short as possible so the energy from the eccentric contraction isnt lost (lots is lost as heat)

uses the stored energy to increase the force of contraction

how fast a person can move or how quicly a body part can be put into motion

its effective in most sports but mostly in games when combined with agility, which is the ability to move and position the body quickly and effectivley whilst under control

a combination of speed, co-ordination, balance and flexibility. these can all be develope through SAQ

multi-directional movement through developing the neuromuscular system

the anaerobic system