energy systems Flashcards
1
Q
why do we need energy for exercise
A
more exercise = more energy
need constant supply to complete daily tasks
2
Q
role of ATP in exercise
A
- energy from food has to be converted into ATP before energy can be used
- enzymes are used to break down ATP into ADP and single phosphate
- ATP in muscle fibres, used within 2-3 seconds need to be resynthesis, done by joining ADP and single phosphate
3
Q
ATP
A
- adenosine triphosphate
- energy we use for muscle contractions
- only usable form of chemical energy in the body
4
Q
ATP molecule
A
- adensoine
- 3 phosphates
5
Q
energy systems
A
- ATP-PC system
- anaerobic system
- areobic system
- each is suited for intensity and duration + whether oxygen is present
6
Q
ATP-PC system
A
- trigger release of creatine kinase, causes phosphocreatine to be broken down anaerobically
- found in sarcoplasm of muscles
lasts 10 seconds - peak 3-5 seconds
- every 1 molecule of PC broken down there is enough energy released to create 1 molecule of ATP
- breaking down of PC to released energy is a coupled reaction
7
Q
advantages of ATP-PC system
A
- ATP can be synthesized rapidly using the ATP-PC system
8
Q
disadvantage of ATP-PC system
A
- only limited supply of phoshocreatine in muscle cell
- PC re-synthesis can only take place in the presence of oxygen
9
Q
anaerobic system
A
- lasts 3 minuets
- peak 1 minute
-eg boxing - glucogen broken by phosphorlayse into glucose
- broken down by phosphofructokinase into pyruvic acid
- cant be stored alone so converted into lactic acid (by product)
- 2 ATP produced
10
Q
advantage of anaerobic system
A
- ATP can be resynthesis quite quickly due to very few chemical reactions and lasts longer than the ATP-PC system
11
Q
disadvantage of anaerobic system
A
- lactic acid as the by-product
12
Q
aerobic system stages
A
- aerobic glycolysis
- krebs cycle
- electron transport chain
13
Q
aerobic glycolysis
A
- breakdown of glucose to pyruvic acid
- 2 ATP
- same as anaerobic glycolysis but occurs with oxygen
14
Q
krebs cycle
A
- once pyruvic acid diffuses into matrix of mitocondria cycle of reactions occur
- 2 ATP and also C02 removed
- hydrogen is taken to the electron transport chain
15
Q
Electron Transport Chain
A
- hydrogen splits into hydrogen ions and electrons and these are charged with potential energy
- hydrogen ions are oxidized to form water
- provides energy to resynthesise ATP
- 34 ATP molecules formed
16
Q
energy continuum
A
which energy system is used for different types of physical activity
17
Q
energy system threshold
A
when one energy system is exhausted and the other one takes over
18
Q
slow twitch muscle fibres
A
- aerobic system
- maximum amount of ATP available from each glucose molecule (upto 36)
- less likely to fatigue
19
Q
fast twitch muscle fibres
A
- anaerobic energy sytem
- only 2ATP produced
- fatigue easier
20
Q
oxygen consumption
A
- amount of oxygen we use to produce ATP
- known as VO2
21
Q
oxygen consumption during exercise
A
- oxygen consumption increases - use more oxygen to produce more ATP
- insufficient O2 is distributed to the tissues for all energy to be provided aerobically
- takes more time for circulatory system to respond to higher demands
- energy is provided anaerobically
- causes O2 deficit
21
Q
vo2 max
A
- maximum volume of O2 that can be taken up and used by the muscles per minute
- 3-6 litres per minute
21
Q
EPOC
A
- excess post-exercise oxygen consumption
- amount of oxygen consumed during recovery about that which would have been consumed at rest during the same time
21
Q
fast component of EPOC
A
- uses extra O2 which is taken in during recovery
- resnythesis of muscle ATP and replenishment of phosphocreatine stores and re saturation of muscle myglobin with oxygen
- high intensity- creates oxygen debt, fast component focuses on repaying by resting levels
- immediately after exercise - 2-3 minuets
21
oxygen deficit
volume difference between an ideal and real O2 uptake
21
slow component of EPOC
- hours after exercise, vo2 higher than resting levels
- lactic acid removed - converted to pyruvic acid then glucose and glycogen (cori cycle) which removed by sweat/urine
- glycogen replenished - stored in muscles as glucose
- sustaining recovery process - maintenance of HR and BR, increase body temp
21
lactate accumulation
- lactic acid breaks down releasing hydrogen ions
- remaining then combines with sodium ions to form salt lactate
- accumulates in muscles, more hydrogen ions present- increase acidity
- slows down enzyme activity affects breakdown of glycogen causing muscle fatigue
21
lactate threshold
- point during exercise at which lactic acid quickly accumulates in the blood
- occurs when body works anaerobically
21
factors affecting lactate accumulation
- exercise intensity
- muscle fibre type
- rate of blood lactate removal
- respiratory exchange ratio
- fitness of performer
21
OBLA
- onset blood lactate accumulation
- point at which the concentration of lactate acid in the blood rapidly increases
- occurs when lactate levels go over 4mmol/L
- measuring gives indication of endurance capacity
21
factors affecting lactate accumulation
exercise intensity
- greater intensity = greater demand for ATP production
- more glucose broken down= more lactic acid produced through anaerobic glycolysis
21
factors affecting lactate accumulation
muscle fibre type
- fast twitch- more anaerobic enzymes, greater capability to quickly break glucose down- more lactic acid
21
factors affecting lactate accumulation
respiratory exchange ratio
- rate of CO2 produced: 02 consumed
- ratio value close to 1:0, glycogen become preferred fuel, greater chance of accumulation
21
factors affecting lactate accumulation
rate of blood lactate removal
- if rate of production is greater than removal
21
factors affecting lactate accumulation
fitness of performer
- fitter person- more mitocondria and myoglobin, increase capacity or aerobic respiration- avoid the use of lactate anaerobic system
21
buffering
aids the removal of lactate and maintains acidity levels in the blood and muscle
21
VO2 max
- maximum volume of air that can be utilized per minute/unit of time
- higher VO2 max the more delay in lactic acid build s up, lactate threshold increases
- average women 35-44 ml/kg/min
21
factors affecting VO2 max
- physiological
- lifestyle
- body composition
- gender
- age
- training
-genetics
21
cori cycle
- lactic acid is transported in the blood to the liver where it is converted to blood glucose and glycogen
21
measurements of energy expenditure
- indirect calorimetry
- lactate sampling
- VO2 max test
- RER
21
indirect calorimetry
overview
- provides accurate estimate if energy expenditure through gas exchange
- measures how much CO2 is produced and how much O2 is consumed
- determines energy requirements and responds to nutrition over time
21
indirect calorimetry
method
- headgear from cart is attached to performer
- inspired and expired gas flows, volumes + concentrations of O2 and CO2 measured then converted into heat equivalent
- measured as REE
21
lactate sampling
- taking small blood sample (earlobe or fingertip) and a handheld device analyses the blood and indicates how much lactate is present
- taken before during and after exercise
- the higher the exercise intensity at which lactate threshold occurs, the fitter the athlete is
- idea of level of fitness
- allows performer to select relevant training zones
21
VO2 max test
- the multi stage fitness test - only gives prediction
- direct gas analyse - increasing intensity on treadmill, runs to exhaustion while air that is expired is calculated by computer, volume and concentration of O2 in expired air is measure and compared with % of O2 in air to see how much O2 has been used
21
respiratory exchange ratio
RER
- ratio of CO2 produced compared to O2 consumed
- RER= CO2 per minuet ./. O2 consumed per minute
- RER value close to 1 - using carbs
- RER value approx to 0.7- using fats
- RER value greater than 1 - anaerobic respiration
- calculating RER determines which energy source is being oxidised and whether working an/aerobically
21
respiratory exchange ratio
method
- perfomer attached to gas analyser
- on treadmill or cycle ergometer, helps create accurate readings for athlete
21
respiratory exchange ratio
factors
- muscle glycogen content
- training volume
- amount of type 1 fibres
- lactate
- dietary fat intake
21
altitude training
- PP of O2 decreases higher
- 2500m+
- less O2 drawn to alveoli per breath
- creates shallower diffusion gradient between alveoli and capillary blood - less diffusion occurs
- haemoglobin less saturated -less O2 delivered
- body acclimates to conditions develops way to cope with O2 reduction
21
altitude training
over time benefits
* more alveoli
* greater capillary network
* blood+ muscles that function in slight hypoxic state
* body needs to develop more red blood cells - EPO is produced
21
HIIT training
- both an/aerobic training
- short intervals of maximum intensity followed by recovery interval of low to moderate intensity
- work is anaerobic, recovery is aerobic
- improves fat burning, glucose metabolism
22
HITT training
variables
- duration of work interval / recovery
- intensity of work interval
- number of work intervals / recovery
23
plyometrics
- high intensity explosive activities and uses fast twitch muscle fibres
- muscles can generate more force if they have been previously stretched
- eccentric phase then amortisation phase ( time between eccentric and concentric muscle contractions) then concentric phases (uses stored energy to increases force of contraction)
24
speed agility quickness
- improves multi-directional movement through developing the intramuscular system
- eg zig zag runs, foot ladders
- maximum force at high speeds
- energy provided anaerobically
