Energy Systems :) Flashcards
adenosine tri-phosphate
atp is the only useable form of energy in the body
energy from atp
energy is released by breaking down bonds via enzymes
-atp-ase breaks down atp into adp and pi
adp needs to be resynthesised either using food or phosphocreatine
aerobic system
used when intensity is low and oxygen supply is high
3 stages: glycolysis, krebs cycle, electron transport chain
glycolysis
in sarcoplasm of muscle
2 atp molecules formed
- glycogen into glucose via glycogen phosphorylase
- breakdown of glucose into pyruvic acid by phosphofructokinase
- split into two acetyl groups, carried by coenzyme a into the krebs cycle
krebs cycle
- series of cyclical reactions that produce energy
- coenzyme a combines with oxaloacetic acid to form citric acid
- this gives of carbon and hydrogen
- carbon forms carbon dioxide and is breathed out
- hydrogen taken to next stage - etc
- happens in matrix of mitochondria
- 2 atp molecules formed
beta oxidisation
process where fatty acids are broken down into acetyl co-enzyme a to enter the krebs cycle
electron transport chain
- hydrogen spilts into ions and electrons charged with potential energy
- electrons used to resynthesise atp
- ions are oxidised to form water
- happens in critae of mitochondria
- 34 molecules of atp produced
atp-pc system
- phosphocreatine is broken down by creatine kinase
- releases energy used to resynthesise ADP into ATP
- 1 ATP produced at fast rate
anaerobic glycolytic system
- glycogen into glucose (glycogen phosphorylase)
- glucose into pyruvic acid (phosphofructokinase)
- pyruvic acid into lactic acid (lactate dehydrogenase)
- produces 2 ATP
energy continuum
v high (>10) ATP-PC
high to v high (8-90 secs) ATP + ANAEROBIC
high (90 secs to 3 mins) ANAEROBIC + AEROBIC
low to medium (3+ mins) AEROBIC
slow twitch fibres atp generation
- main pathway via aerobic system
- produces max atp amount from each glucose molecule (36)
- production is slow but endurance based so less fatigue
fast twitch fibres - atp generation
fast twitch fibres recruited for high intensity - anaerobic resp
- main pathway for atp production is lactate anaerobic system (during glycolysis)
- atp production with no oxygen is not as efficient (2 mols)
- production is fast but cant last for long as fatigue quickly
oxygen consumption
amount of oxygen we use to produce atp
submaximal oxygen deficit
at the start of exercise there isnt enough oxygen available to provide all energy aerobically so its provided anaerobically to satisfy the increased demand for energy
maximum oxygen deficit
maximal accumulated oxygen deficit
gives indication of aerobic capacity
epoc
amount of oxygen consumed during recovery above what would be consumed during rest
fast replenishment stage
restoration of atp
-takes up to 2 mins and uses 0.5 l of oxygen
restoration of phosphocreatine stores
-complete re-saturation takes up to 3 mins but 50% of stores replenished after 30 seconds
re-saturation of myoglobin with oxgen
slow replenishment stage
removal of lactic acid
-5/6 litres of oxygen in 30 mins - 50% of lactic acid removed
maintenance of breathing and heart rate
glycogen replenishment
increase in body temp
removal of lactic acid
- oxidisation into co2 and water in inactive muscles to be used as energy
- transported into liver vid blood then converted into glucose
- converted into protein
- removed in sweat and urine
- oxidisation in mitochondria so cool down helps flushing through
cori cycle
the process where lactic acid is transported in the blood to the liver where it is converted into blood glucose and glycogen
maintenance of breathing and heart rate
requires extra oxygen for energy for respiratory and heart muscles
extra oxygen used to replenish ATP + phosphocreatine stores
glycogen replenishment
30 mins post ex: carbs and protein in 3:1 or 4:1
1-3 hours post ex: meal high in protein, carb and healthy fat
increase in body temp
higher temp leads to higher respiratory rates = more oxygen
lactate accumulation
- as lactate accumulates in muscles, more hydrogen ions are present
- acidity is increased slowing down enzyme activity
- glycogen breakdown affected leading to muscle fatigue
- lactate diffuses into blood and level can be measured
factors affecting lactate accumulation
-exercise intensity
higher the intensity of exercise faster obla occurs
-muscle fibre type
slow twitch fibres produce less lactate - glycogen broken down effectively
-rer
ratio of close to 1.0 means more lactate will accumulate
-rate of blood lactate removal
the slower the removal rate the more lactate will accumulate
-fitness of performer
fitter performer can delay obla by increasing mito & myo to use aerobic system
obla
the point where the lactate levels go above 4 millimoles per litre
lactate threshold
the point when lactate starts rapidly accumulating in the blood
- percentage of vo2 max (average 50-60)
- fitter you are the higher your lactate threshold percentage is
vo2 max
the maximum amount of oxygen that can be utilised by the muscles per minute
-largely genetically determined
buffering
process which aids the removal of lactate and maintains acidity levels in the blood and muscle
-athletes can work at higher intensities for longer before fatigue
indirect calorimetry
measures how much carbon dioxide is produced and how much oxygen is consumed at rest and during exercise
precise calculation of vo2 max (max amount of oxygen muscles can use in 1 min)
lactate sampling
blood samples taken at progressive levels to analyse lactic acid levels
when lactic acid reaches 4 mmols = lactate threshold
obla score written as a % of your VO2 max
useful for endurance athletes
vo2 max test
bleep test - 12 min copper run - direct gas analysis
exercise is performed (on ergometer?) increasing gradually, concentration of oxygen inspired and concentration of co2 expired recorded
athlete is considered to have reached their VO2 max: a plateau or ‘peaking over’ in oxygen uptake, maximal heart rate reached, attainment of a respiratory exchange ratio of 1.15 or greater, and exhaustion
respiratory exchange ratio
ratio of carbon dioxide produced compared to oxygen consumed
calculates energy expenditure and info about carbs and fats used
rer closer to 1 - using carbs
rer of 0.7 - using fats
rer greater than 1 - anaerobic respiration
altitude training
done at 2500 above sea level where partial pressure is lower
- body to produces greater amounts of EPO (erythropoietin) in the kidneys,
- increase in red blood cells produced
- when the athlete competes at sea level - there is a greater amount of oxygen carrying red blood cells available
- greater transport of oxygen to the muscles for metabolism
altitude training advantages
- increased number of red blood cells
- increased concentration of haemoglobin
- increased blood viscosity
- increased capillarisation
- enhanced oxygen transport
- increased lactate tolerance
altitude training disadvantages
- expensive
- altitude sickness
- difficult to train due to lack of oxygen
- detraining because intensity has to reduce when they first train
- benefits quickly lost when back at sea level
- psychological problems when away from home
hitt
used for both aerobic and anaerobic training
short intervals of maximum intensity followed by recovery interval of low intensity
improves fat burning potential, glucose metabolism and an/aerobic endurance
plyometrics
repeated rapid stretching and contracting of muscles to increase muscle power
(jumping, hopping, bounding) fast twitch fibres
-muscles can generate more force if previously stretched
stretch shortening cycle:
1.eccentric phase or pre-loading phase: on landing muscle performs eccentric contractions where is lengthens under tension. some energy lost as heat
- amortisation phase: time between eccentric and concentric contractions. needs to be as short as possible so energy stored from eccentric contraction isnt lost
- concentric/contraction phase: uses stored energy to increase force of contraction
saq
speed is how fast a person can move over a specified distance or how quickly a body part can be put into motion
agility is ability to move and position the body quickly whilst controlling it
saq aims to improve multi-directional movement through developing neuromuscular system
-zigzag runs, foot ladders and passing a ball quickly
uses activites performed at maximum force at high speed - anaerobic energy
factors affecting vo2 max
