C1 Ex Phys A Flashcards
energy
- what
- key roles (4)
- how much per day?
- energy is the ability to perform work
- comes from the breakdown of ATP
- key roles: 1. muscle contraction, 2. repair tissues, 3. nerve conduction, 4. hormone manufacturing
- typical person uses their own body weight + over in ATP per day
ATP
- role
- stored as?
- describe ATP splitting
- role of energy systems
- powers all metabolic reactions
- stored as glycogen or fat
ATP splitting
1. ATP molecule - 1 adenosine, 3 phosphates (Pi)
2. ADP molecule - 3rd Pi breaks off, releases energy, cause muscle contraction
3. ATP molecule - fuel used to resynthesise 3rd Pi to ADP
- ATP splitting/resynthesis must occur on an ongoing basis to generate constant energy
- this is the role of energy systems - breakdown fuel and use the energy to resynthesise ATP
creatine phosphate
- names
- storage
- sources
- usage
- known as: phosphocreatine, PC, CP, PCr
- storage: muscle + brain cells
- sources: half from food, half resynthesised by the body (in liver, kidneys, pancreas)
- usage: produces energy by splitting (used to regenerate ATP)
carbohydrates
- what
- transport
- storage (3)
- glycemic index
- includes sugars + starches, simple or complex
Transport: - broken down by digestive system into glucose
- transported in blood
- also, glucose is released from liver into blood to control blood glucose lvls
Storage: - in blood (GLUCOSE)
- in muscles + liver (GLYCOGEN)
- as fat (ADIPOSE TISSUE)
GLYCEMIC INDEX
- high GI - 70-100: quickly broken down, rapid energy release (jelly beans, sports drinks, fruit juice)
- medium GI - 55-70: (bread, couscous, sweet potato)
- low GI - 0-55: slow, sustained long term energy release (lentils, milk, carrots)
fats
-what
- made up of…
- transport
- storage
- sources
- why is it important? (6)
- high energy molecules
- made up of: triglycerides + fatty acids
- sources: food (oils, butter, avo, dairy, meat), and produced from storage of excess carbs
- transport: in blood as free fatty acids (FFAs)
Storage: - mostly as adipose tissue
- in muscles + liver (triglycerides)
- in blood (FFAs)
Important: - energy from fat breakdown mostly used during rest + periods of low int, sub max exercise
- produces most energy/gram than other fuels
- provides up to half of body’s everyday energy
- provides protection for organs
- production of cell membranes, hormones, cholestrol
- primary fuel source when carbs are depleted (long periods of exercise)
proteins
- made from…
- roles (4)
- usage
- transport
- storage
- made from AAs
Roles: - formation + growth of body tissues (esp muscles)
- repair + recovery of damaged tissues
- production of RBCs, hormones, enzymes
- emergency fuel source
- usage: event of extremity, after carbs/fats depleted (eg. ultra marathon, starvation)
- transport: in blood (AAs) to sites where needed
Storage: - not technically ‘stored’
- in blood/body fluids (AAs)
- in skeletal muscle (AAs)
- excess AAs converted to adipose tissue
hitting the wall
- occurs when liver + muscle glycogen stores are depleted
- fats must be used as primary energy source
- breakdown of fat is slow compared to carbs (requires more energy)
- ATP production is slowed
- results in sudden fatigue, decreased power output
- only occurs after extended period of exercise
glycogen sparing
- glycogen stores are not used early on in exercise due to body’s increased ability to use triglycerides as fuel
- aerobic system can metabolise fats efficiently, preserving glycogen stores for later
- this delays glycogen depletion, allowing athlete to access them at a later point
- = delayed exhaustion
ATP production during REST
(aerobic + fuel sources)
- energy requirement = low (not under physical stress)
- all energy supplied aerobically due to abundant O2 supply
- occurs in mitochondria
Fuel sources
- mostly fats (2/3), stored w/i muscle + body adipose tissue
- glucose/glycogen (1/3), breakdown in muscles + liver
- fat is richer source of energy, however requires abuandance of O2 to breakdown. therefore it is used at rest
ATP production during EXERCISE (anaerobic - why?)
- energy requirement = high
- body under physical stress = increased O2 demand to working muscles
- respiratory + circulatory systems unable to meet this
- body starts producing energy anaerobically
- if the activity is sub max, aerobic can be used
traits of anaerobic vs aerobic systems
Anaerobic
- provides energy quickly + powerfully in absence of O2
- only operate for short period
- small ATP yield
- produce toxic byproducts with cause fatigue
Aerobic
- produce ATP for sustained period of time (at rest or sub max)
- slow, sustained release, not rapid
- large ATP yield
- no toxic byproducts
Why are both anaerobic + aerobic systems necessary?
- aerobic = effecient at producing ATP (large yield, long period of time, sustained release)
- however, anaerobic is essential as O2 transportation is not efficient enough to sustain ATP production during higher int exercise
- limited speed by circ + resp systems
- CO2/O2 exchange is often not rapid enough to sustain the body’s ATP supplies
- need to be able to produce energy w/o O2!!!!
ATP-PC system
- when?
- system type
- fuel
- duration
- effectiveness
- When: power/explosive efforts (sprint, throw, weight lift, jump)
- anaerobic (no O2)
Fuel
- phosphocreatine (PC)
- stores located w/i muscle
- ATP produced through PC breakdown in muscle
- splitting of PC allows a phosphate to synthesise to an ADP molecule = ATP
- this occurs until PC stores are depleted
Duration
- two parts of the system
- ATP stores w/i muscle (0-2 sec)
- PC stores (2-10 sec)
- overall, ATP-PC system dominant for first 10 sec of max effort exercise
- takes 3-5 min to restore ATP/PC stores w/i muscles during rest
Effectiveness
- speed is fast: produces ATP almost instantly
- however: produces a limited quantity of ATP, depleted quickly
lactic acid system
- when?
- system type
- byproducts
- fuel
- duration
- process
- dominant during high int (still sub max) exercise (400m sprint, 500m row, team game)
- anaerobic (no O2)
- Fuel: glycogen/glucose, the incomplete breakdown of glucose (anaerobic glycolysis)
- Duration: dominant from 10-30 sec until 2-3 min of high int (after which aerobic takes over)
PROCESS
- glycogen (stored in liver + skeletal muscle)
- broken down to glucose
- converted via GLYCOLYSIS to
- pyruvic acid (small ATP yield)
when insufficent O2 (too much pyruvate for aerobic system to use), converted to
- = LACTIC ACID, H+ ions
lactic acid accumulation
- lactic acid is produced by body constantly
- during rest + most exercise (not max), lactic acid production = the rate at which it is removed
- = no accumulation
AT HIGH INT:
- lactic acid & H+ ion production increases, rate of removal increases
- athlete will reach their lactate threshold
- if continued, LA + H continue to increase expotentially
- increase in muscle acidity, fatigue,
- cannot physically continue, must slow or stop
lactate threshold/lactate inflection point (LIP)
- graphs
- the point at which the production of lactate is greater than the rate of its removal
- once reached, LA + H increase expotentially
- also referred to as OBLA
lactic acid removal
- determined by?
- fates of LA
- rate of removal (muscle to blood stream) determined by rate of blood flow thru muscles)
FATES
- a little taken up by heart + skeletal muscle, converted to pyruvic acid, used for ATP
- MAJORITY converted by the liver to:
- 65% resynthesised to CO2 + H2O
- 20-25% to glycogen
- 10% to protein
- 5% to glucose
aerobic system
- when?
Location, fuel, process, byproducts, yield:
- glycolysis
- citric acid cycle
- electron transport chain
- dominant during sub-max efforts from 2-5 min onwards
- most efficient system, produces most ATP overall
- slow ATP production, large yield
- CO2, H2O + heat byproducts
GLYCOLYSIS
- occurs in muscle cell
- glycogen -> glucose -> pyruvic acid
- anaerobic breakdown of glycogen/glucose
- occurs in both aerobic + anaerobic systems (in LA system, P is converted to lactate instead)
- only needed when carbs are used as the fuel source (fats + proteins go straight to next stage)
CITRIC ACID CYCLE
- occurs in mitochondria
- fuel: pyruvic acid / fats (lipolysis) /prtoteins
- aerobic, fuel combines with O2
- byproducts: CO2 (released via lungs), H+ ions (used in next stage)
- ATP yield: small
ELECTRON TRANSPORT CHAIN
- occurs in mitochondria
- byproducts: H2O (diffuses into tissues/blood), heat (released)
- aerobic
- ATP yield: LARGE (majority)
Summarise the AEROBIC system (flow chart process)
- glycogen
- glucose
- broken down via GLYCOLYSIS (small ATP yield) to:
- pyruvate (or fats/proteins used instead)
- if O2 present:
- CITRIC ACID CYCLE (byproducts: CO2 - released, H+ ions - used) + small ATP yield
- E TRANSPORT CHAIN (byproducts: H2O - diffuses into body, heat - released) + large ATP yield
- total: 30-38 ATP
roles of haemoglobin vs myoglobin
- H: TRANSPORTS O2 in the blood to capillary beds of muscles
- M: ATTRACTS O2 from bloodstream into muscle cells + STORES O2 within muscle cells
myoglobin (definition + role)
- red oxygen binding protein in skeletal muscle cells
- when O2 diffusion from blood -> muscle is too slow for O2 demands, myoglobin will release O2
- ROLES: ATTRACTS O2 to muscles, STORES O2 in muscles, RELEASES O2 when needed
- usually during intermittent exercise
Describe how aerobic training enhances O2 efficiency within the body.
enhances the body’s ability to attract O2 into muscle cells = performance increase:
- increased size + number of mitochondria
- increased myoglobin stores
muscle fibre types
- how does it vary w/i individuals?
List the:
Aer/an, fatigue res, blood supp, colour, fibre diameter, contract speed/force, mito, exercise type:
- slow twitch 1A
- fast twitch 2A
- fast twitch 2B
- skeletal muscle fibre makeup is determined by genetics
- all muscles contain varying proportions of fibres w/i them
- fibre makeup varies w/i diff muscles of smae indv. eg. slow dom leg, vs fast dom arm
SLOW TWITCH (1A)
- aerobic
- high fatigue resistant
- red
- small fibre diameter
- contract slowly, low force
- high mitochondria
- endurance exercise (repeated contractions)
FAST TWITCH (2A)
- anaerobic + aerobic
- medium fatigue resistant
- pink
- medium fibre diameter
- contract rapidly, medium force
- medium mitochondria
- medium distance/efforts (repeated contractions)
FAST TWITCH (2B)
- anaerobic
- low fatigue resistant
- white
- large fibre diameter
- contract rapidly, high force
- low mitochondria
- short, rapid, intense efforts
energy system interplay
the ongoing and continual overlapping contribution of the 3 energy systems during exercise
Describe how energy system interplay changes dependent on 3 factors:
- duration
- intensity
- activity type
- all 3 energy systems operate at any one time
- however, which system is DOMINANT at a given time changes
- transition is gradual
- dominance depends on 3 factors:
DURATION
- ATP-PC: 0-10 sec dominant
- LA: 10-60 sec dominant
- Aerobic: over 1-2 minutes becomes dominant (at sub max)
INTENSITY
- high intensity: O2 cannot circulate at a rapid enough rate = ATP-PC + LA system dominant
- low/medium intensity: sub max = aerobic dominant
- @ start of any activity, ATP-PC + LA dominant
- @ any point where aerobic cannot sustain exercise, the anaerobic systems make up the difference
ACTIVITY TYPE
- fast, rapid movements = ATP-PC
- sub-max = aerobic
How does aerobic fitness influence energy system interplay?
will influence which system is the dominant energy producer
- increases in aerobic fitness = better ability to utilise O2 thru delivery/transport
- therefore, better Ae fitness will mean the aerobic system will become dominant earlier on.
acute responses vs chronic responses
- how are they grouped?
- acute: immediate changes w/i the body in response to exercise
- chronic: long-term, semi-permanent adaptations as a result of regular exercise (take at min 6 weeks to develop)
- responses can be grouped into 3 categories: cardiovascular, respiratory, muscular
CARDIOVASCULAR acute responses
- what do they do?
- list (7)
facilitate the efficient delivery of O2 to working muscles in order to meet the increased demand for energy
- > HR
- > SV
- > Q
- > BP
- changed blood redisribution
- > a-VO2 diff
- > GE
CARDIOVASCULAR acute responses
- heart rate (HR)
- increased
- > demand for fuel, O2 + removal of waste products
- heart required to pump faster + harder to supply > blood to body
- MHR = 220 - age
CARDIOVASCULAR acute responses
- stroke volume (SV)
- increased
- volume of blood ejected from left ventricle w each beat (mL/beat)
- increases then plateaus
- affected by 3 factors:
- Frank-Starling Mechanism (> amount of blood in L ventricle = stronger contraction = more blood returning to heart - a cycle)
- Neural Stimulation (nerves in heart increase contractions)
- Peripheral Resistance (resistance of blood movement caused by small vessels is decreased by vasodilation)
CARDIOVASCULAR acute responses
- cardiac output (Q)
- volume of blood pumped by heart per minute (L/min)
- Q = SV x HR
- also increased by chronic adapation
CARDIOVASCULAR acute responses
- blood pressure (BP)
- increased
- the pressure exerted by the blood against the walls of the blood vessels as it circulates
- eg. 120/80
- Systolic: BP as heart contracts (ejects), higher + first of two values
- Diastolic: BP as heart relaxes (fills), lower + second of two values
- BP affected by: gender (females have lower), age (increases), exercise (increases Sys BP), stress/excitement (increases)
CARDIOVASCULAR acute responses
- blood redistribution
- changes
- systemic blood flow = flow of blood around the body, affected by:
- VASODILATION: capillaries + arteries expand, increasing blood flow
- VASOCONSTRICTION: capillaries + arteries constrict, decreasing blood flow
- blood flows to tissues/cells based on lvl of activity and therefore O2 demand
- more blood is suppled to body parts working harder than others.
During rest:
- constrict to muscles (not needed), dilate to organs
- 15-20% systemic blood flow to muscles
During exercise:
- dilate to muscles (needed), constrict to organs
- 80-90% systemic blood flow to muscles
CARDIOVASCULAR acute responses
- arteriovenous blood difference (a-VO2 diff)
- increased
- the diff between blood O2 conc in the arteries versus the veins (mL/100mL)
At rest:
- arteries have a greater conc of O2
- O2 diffuses into blood from lungs
- O2 rich blood moves from heart into arteries
- carried around body, diffuses out
- returns via veins
During exercise
- demand is increased
- more O2 required, more is used from the blood
- therefore, venous blood returning will have a lower O2 conc compared to @ rest
- = a-VO2 diff is GREATER during exercise
- REST: arteries around 20mL/100mL, veins 15mL/100mL
- EXERCISE: arteries around 20mL/100mL, veins 5mL/100mL
CARDIOVASCULAR acute responses
- gas exchange
- changes
- O2 into blood from lungs, CO2 out of blood and respired in exhale
- site of external GE: alveoli (air-blood, blood-air)
- site of internal GE: muscle fibres (blood-cells, cells-blood)
RESPIRATORY acute responses
- what do they do?
- respiratory rate (RR)
- tidal volume (TV)
- pulmonary/minute ventilation (VE)
- O2 uptake (VO2)
- facilitate an increase in O2 availability and CO2 removal (= enhance gas exchange)
RR
- increases
- no. breaths taken per min (/min)
- increases in exercise due to > O2 demand
TV
- increases
- volume of air inhaled AND exhaled per breath
VE
- increases
- volume of air moved in AND out of respiratory tract each minute (L)
- VE = RR x TV
VO2
- increases
O2 DEFICIT
- define
- why does it happen?
O2 DEFICIT: when there is a difference between the amount of O2 required for the task (demand) and the amount the body is able to supply
Why?
- aerobic system is preferred over anaerobic systems (more efficient, no byproducts)
- when moving from rest -> exercise, or to a higher intensity, aerobic system takes time to adjust its acute responses to meet the new demands of the activity.
- O2 cannot circulate rapidly enough = a deficit occurs.
- therefore, anaerobic systems supply energy to compensate/ make up the difference.
STEADY STATE
- define
- why is it ideal?
- depends on?
- moving b/w steady states
- when there is a balance between the body’s energy demand and the energy supply
- O2 demand = O2 supply
- an ideal state: means aerobic system is primarily being used, no toxic byproducts, + a fuel abundance
- depends on fitness lvls (trained athletes have better CVR system - efficient at processing O2)
- moving b/w steady states causes an O2 deficit (due to adjustment of aerobic system to meet new demands)
EPOC
- define
- purpose?
- describe graph
- excessive post-exercise O2 consumption
- the ‘extra’ O2 consumed during a recovery period after exercise (shown by increased TV, RR, HR etc)
- EPOC ‘replaces’ the O2 deficit accrued during exercise, repaying the debt
- on a graph, EPOC is demonstrated by a gradual decline in VO2 (not a sharp drop immediately after).
VO2
the volume of OXYGEN being taken up + used by the body at ANY given time (L/min)
- at rest: around 0.25L/min
- increases during exercise
VO2 MAX
- define
- absolute vs relative (units?)
- usefulness
the MAXIMAL amount of oxygen able to be consumed per minute at max lvl intensity exercise (L/min)
- Absolute: does not take body mass into account (L/min)
- Relative: DOES take body mass into account (mL/min/kg)
- useful as can be used as an indicator of aerobic potential/success
List the factors affecting VO2 max (5).
- Aerobic fitness: chronic adaptations due to training enhance VO2 max (> fitness = > VO2 max)
- Body size: O2 + energy demands differ + are relative to size, bigger size = bigger CVR system
- Gender: women in general have lower VO2 maxes due to less muscle mass + more adipose tissue
- Genetics: people can improve their VO2 max, but the extent to which they can is predetermined
- Age: declines rapidly after 50, can peak as early as early teens
LACTATE THRESHOLD/LIP
- define
- how can LIP be estimated? (values)
- improving LIP (2)
- buffering
- LIP: the point at which the production of lactate is greater than the rate of its removal
- far better indicator of performance than VO2 max
- it is highly trainable
LIP can be estimated through an indv.’s HR + VO2 max:
- Trained: 90% MHR, 70-80% VO2 max
- Untrained: 60% MHR, 50-60% VO2 max
Can be improved by:
- continuous pace (aerobic SS)
- interval/intermittent training (aer + anae)
Buffering
- the body will use lactate to assist in the removal of H+ ions from the muscles
- this neutralises/decreases the acidity
- allowed muscles to continue working for longer
- LIP training enhances buffering abilities
List the MUSCULAR acute responses to exercise (6).
- increased motor unit + muscle fibre recruitment
- increased blood flow to muscles (vaso con/res)
- increased muscle temp
- increased enzyme activity (to produce ATP)
- increased O2 supply + use
- decreased muscle energy stores (ATP, PC, glycogen + triglycerides)
CHRONIC ADAPTATIONS circulatory-respiratory
- at rest
- during sub max
- during max
AT REST
- > SV
- >blood volume + haemoglobin
- > capillarisation of heart + skeletal muscle
- < RHR
- < BP
- < lung ventilation
- > cardiac hypertrophy
DURING SUB MAX (aerobic)
- > SV
- > LIP
- > a-VO2 diff
- < HR
- < min ventilation
- < BP
- < or unchanged VO2
- UNCHANGED Q
DURING MAX (anaerobic)
- > SV
- > Q
- > VO2
- > LIP
- > or unchanged musc blood flow
- > min ventilation
- > a-VO2 diff
Describe the chronic adapation of CARDIAC HYPERTROPHY. (endurance vs non-endurance athletes)
- circulatory-respiratory adapation
- refers to the size and thickness of the heart muscle
- endurance athletes: left ventricle becomes larger, no increase in ventricle wall thickness
- non-endurance: left ventricle wall becomes thicker, no change in ventricle size
CHRONIC ADAPTATIONS muscular
- endurance training
- non-endurance training
ENDURANCE TRAINING (aerobic)
- > no. + size of mitochondria
- > myoglobin conc
- > O2 utilisation
- > oxidation of fats (glycogen sparing)
- > stores of triglycerides, glycogen + ATP-PC
- > size of slow twitch muscle fibres
- < utilisation of anaerobic system
NON-ENDURANCE TRAINING (anaerobic)
- >ATP-PC system capacity (> ATP/PC stores + enzymes)
- > glyocolytic capacity (> glycogen stores + enzymes
- > size of fast twitch muscle fibres
- > speed + force of musc contraction
- > no. muscle capillaries
- > strength of connective tissue
