Chronic adaptations Flashcards
Chronic adaptaions
Long term physiological change that occurs as a result of training
can be structural (changes to the structure of the heart, blood vessels, lungs and muscles) or functional (changes to how the heart, blood vessels, lungs and muscles work)
are specific to the type of training completed
leads to improved performance.
Aerobic chronic adaptations
minimum period for chronic adaptations to occur with aerobic (endrance) is 6 weeks.
usually developed to bring more o2 into the body
developed thru continuous fartlek long interval and HIIT training sessions
they can also be developed through circuit and resistance training
chronic aerobic adaptaions result in an increased ability of the athlete to produce ATP aerobically or an improved economy
What does O2 delievery depend on?
- ability of lungs to ventilate large volumes of O2
- ability of the blood to exchangeo2 at the luns (transported by haemoglobin in red blood cells)
-ability of the heart to pump large volumes of blood to muscles (Q=HRxSV)
-ability of muscles to use O2 to breakdown fuels to produce ATP (occurs in mitochondria and requires oxidative and glycolytic enzymes)
Vital Capacity
Maximum amount of air a person can expel from the lungs after maximum inhalation. Gets rid of waste like CO2
Ventilation and adaptations
Amount of air breathed in per min
v=rrxtv
ADAPTATIONS:
-ventilation at rest- decreases due to increased efficiency
- ventilation at sub-max= decreased due to increased efficiency
- increases at max exercises increasing the supply of oxygen avaliable and therefore ability to work aerobically
Pulmonary diffusion
The movement of oxygen from the alveoli into the capillaries and that of caarbon dioxide from the capillaries into the alveolie to be expelled is known as pumonary diffusion.
Aerobic training brings increases in lung volumes and capillary density around the alveoli, therefore a greater surface area providing more opportunity for diffusion.
IT INCREASES AT ALL INTENSITIES.
Results in more efficient transport of O2 to the working muscles.
Oxygen consumption
Is the volume of oxygen taken up and utilised by the body per minute per kilogram of body weight.
Oxygen consumption at rest and during sub max generally remains unchanged or DECREASES slightly due to an increase in exercise economy.
VO2 max increases substantially following aerobic training due to improved O2 delievery to working muscles.
It is as a result of adaptaions to:
- stroke volume
-heart rate
- A-VO2 difference
an increase of 15 - 20% in VO2 is typical for a sedentary individual who trains at 50% to 85% of VO2 max 3-5 times per week/20min for 6 months
CARDIOVASCULAR ADAPTATIONS
cardiac hypertrophy
The heart is similar to other muscles in that it will experience hypertrophy as a result of aerobic training. Typically there will be an increase in the size and volume of the left ventricular cavity and a slight thickening of the ventricular walls (more anaerobic). This leads to an increase in stroke volume and delievery to oxygen in the working muscles.
Increased capillarisation of heart muscles
Increased capillary density of cardiac tissue improves blood flow to the heart itself.
The heart maintains a very high level of o2 extraction so that 70-80 of the arterially delivered o2 is extracted, compared with 30-50% in skeletal muscles. o2 delievered to the heart is essentially used for contraction
Heart rate
Influence of serobic training on heart rate:
- lower resting heart rate
-lower heart rate response at sub max
- no real change at maximal
- slower heart rate increase during exerice
- lower and faster steady state
-decreased recovery heart rate following sub max exercise
- decreased recovery heart rate following maximal exercise.
changes are related to:
increase stroke volume
adjustments to the control mechanisms of the heart.
improved efficiency of the heart means that it works less to supply the same amount of blood to the body at rest and during exercise.
Stroke volume
Stroke Volume is the volume of blood ejected from a ventricle at each beat of the heart.
increase SV is most pronounced in endurance athletes.
Stroke volume increases at ALL intensities
attributed to:
-increased ventricular cavity size
-increased myocardial contractility
will lead to more oxygenated blood being delievered to working muscles
Cardiac output
Is the volume of blood pumped by the heart per minute
Cardiac output= SV x HR
Following aerobic training:
-Q at rest is unchanged or has a slight decrease
- Q at sub is unchanged
Q at maximal is increased
Blood pressure
Systolic pressure- preseure on the aerteries following contraction of ventricle as blood is pumped out of the heart
Diastolic pressure- pressure in the arteries when the heart relaxes and the ventricles fill with blood
Aerobic training influences the following chronic adaptations:
- bp is decreased at rest
bp at sub max is decreased
bp at max is unchanged
Improved vasodilation of blood vessels, less peripheral resistance
decreased concentrations of total cholesterol
reduced insulin resistance and insulin levels significant contributing factors to the development of hypertension.
Blood vessels
Aerobic training increases the size of the blood vessels by transporting O2 to the heart
results in improved blood flow to the heart and therefore improved oxygen supply to the heart
Aerobic training also increases capillarisation at the skeletal muscles
increased no. of capillaries that surround skeletal muscles
- greaer in slow twitch muscle fibres
- enhances supply of O2 and other nutrients
-improves removal of waste products.
Increased plasma and haemoglobin
Increased total blood volume
increased RBC count
improves oxyggen carrying capacity of the blood and is closely correlated with increase in Vo2 max
increased blood volume also assists temperature control during exercise particularly in hot temperatures as deep body heat is caried to the periphery where it can be dissipated
Increased avo2 difference
difference in oxygen content between arterial and mixed venous blood. Represents the amount of O2 extracted or conusmed by the tissues
Aerobic training leads to an increase in Avo2 difference due to :
- redistribution of blood flow to active muscles (particularly slow twitch)
- greater extraction of O2 by the working muscles as a result of increased mitochondria numbers, more oxidative enzymes and increased myoglobin levels.
Lactate production
Prolonged aerobic training will result in a decrease in blood lactate
Lactate inflection point
is the highest exercise intensity point where lactate production and removal from the blood are balaned. Above this point blood lactate levels will rise rapidly.
(85% max heart rate)
training at lactate inflection point will result in an increase in LIP
this is advantageoud for the athlete as they will be able to work at a higher intensity and therefore a faster pace without large increases in blood lactate levels from reliance on the anaerobic glycoloysis system.
this is as a result of:
- increase mitochondrial density
-increase capilarisation
- increased oxidative enzymes
- istructural changes to the cardiovascular system
MUSCULAR ADAPTATIONS
-muscle structure
Aerobic training will have an effecton the structure of skeletal muscles.
slow twitch fibres will:
- increase in size
- become larger than the fast twitch fibres in the same muscle
- be recruited preferentially
- ave their aerobic capacity improved
Increased myoglobin in the muscle aids in the diffusion of oxygen across the cell membrane from the capillaries to the muscle tissue.
this results in :
- increased stores of O2
- increased diffusion of O2
Mitochondria adaptations
The mitochondria are the palce where aerobic production of ATP occurs.
Aerobic training increases the:
- number f mito
- size of mito
-surface area of the cristae membrane in the mitochondra (just say SA)
these adaptations increase the amount of ATP that can be produced aerobically - therefore endurance athletes can perform at a higher level whilst relying predominantly on the aerobic pathways.
Oxidative enzymes
Speed up the rate of oxidation and therefore the rate of aerobic ATP production
Increase in oxidative enzymes enables the athlete to break down fuels aerobically at a faster rate
Oxidation of fat
Fat is a rich source of fuel during aerobic activity and endurance athletes with trained ability to oxidise fats are at an advantage, as fats produce a higher yeild and therefore they can have more energy production for longer. (im not sure abt this one)
aerobic training increases fat oxidation:
- increases triglyceride stores in the muscle
- increases release of free fatty acid from adipose tissue
increased activity of oxidative enerzymes involved in the activation, transport and breakdown of fatty acid
Glycogen sparing
At sub max levels if endurance athletes can have an improved ability to oxidise fat they can therefore conserve their glycogen stores
these glycogen stores may be needed for anaerobic ATP production such as a sprint to the line or an intense hill climb as glycogen have a faster energy production rate as thus can provide a higher rate of energy to supply the increased demand rather than reliance on fats
Glycogen stores
At sub max levels, glycogen sparing allows trained athletes to decrease oxidation of glycogen
at maximal levels, aerobic training increases the ability of the muscle to oxidise glycogen.
this is because adaptations to aerobic training include:
- increases in glycogen stores
-increased number/size surface aera of mito
-increases in oxidative enzymes involved in aerobic metabolism. this increases ATP production