L22 Flashcards
When you train for aerobic fitness, adaptations include:
Heart Vascular system (blood vessels) Muscles Lungs increase in VO2max increase in CO increase in O2 extracted by the muscles
main change is increase in SV
Hypertrophy (increase in size) left ventricle leads to
– Increase in stroke volume
– Increase in cardiac output
– Increase in contractility- more force/beat (increased SNS)
describe physiological hypertrophy of the heart
All the continue work and pressure that the heart undergoes while under the endurance conditions leads to a physiological hypertrophy of the heart, similar to what you see this in the skeletal mussle
The hypertrophy that you see is the growth within the left ventricle. With a larger chamber of the left ventical you can get a larger SV
Not only goes the chamber size increase so does the thickness of the muscle chamber
Physiological hypertrophy = everything gets bigger but everything is still functional
describe the difference in what you would see with physiological hypertrophy compered to pathological hypertrophy (Mild hypertrophic
cardiomyopathy)
it both causes the thickness of the left ventricular wall is the same however when the wall contracts which physiological hypertrophy the ventical will still have a round shape and will still have some space within the ventical
in Mild hypertrophic
cardiomyopathy there is a non round shape (it is non uniform squeezing of the ventricle) which leads to not enough blood getting pushes out of the ventricle
SV increases with endurance training
how much can it increase by
untrained = 50-70mL/beat at rest and 80-110 during excersize
tained = 70-90 at rest and 110-150 during excersize
highly trained = 90-110 at rest and 150-220+ during exercise
what becomes a measure of fitness as adaption occures
HR
why does HR become a measure of fitness as adaption occures
HR is a really inefficient way to get O2 blood to skeletal muscles as when the HR gets too high the ventricles don’t fill
A better was of increasing the CO is to make the left vertical larger
With training athletes are able to decrease HR to do the same power
The training also lets them go longer before their HR maxes out
therefore lower HR while doing intense exercise is a measure of fitness
how does resting HR change with endurance training
decreases 1 beat per min per week of training
this is because of an increases with parasympathetic signaling to the heart
how does submaximal HR change with endurance training
when it is most obvious
HR decreases for the same intensity of exercise
this becomes more obvious at higher submaximal intensities
how does MAXIMAL HR change with endurance training
there is no significant change with training but it dose decrease with age
how does exercise cause adaptations to the vascular system
Increased blood volume, including plasma levels. • antidiuretic hormone, aldosterone- acts on kidneys to reabsorb water
Increased red blood cells
and haemoglobin
- EPO
The maximal aerobic capacity of muscle increases dramatically
because of adaptations to
exercise training
why is this
increases dramatically
because of these
adaptations which influences the relative smaller changes in
VO2max
(fiber tye, capillary supply and myoglobin)
describe fiber type in terms of muscle adaption to exercise training
Increased size and number of type I fibres (type IIa
converts to type I)
Type IIx may perform more like type IIa
Increased mitochondria and oxidative enzymes
describe cappilary supply in terms of muscle adaption to exercise training
Increased number of capillaries
May be key factor in increased VO2max
describe myoglobin in terms of muscle adaption to exercise training
Increased myoglobin content by 75 to 80%
Supports increased oxidative capacity in muscle (better extraction of O2 from the blood)
how do the fiber types switch between each other
Type 2 fibre can change but type 1 cant
Type 2x can become more like type 2a
Type 2a can become more like type 1
which fiber type has the most mitochondria
type 1
what is the difference is strength training vs endurence
When you do strength training the changes to the mussles is very obious as you get hypertrophy and you get bigger muscels
When you do airobic training the results are not visible as the training chases a changes in the fibre types and the capiliaries that bring the blood to the muscles
what is vasculogenesis
making of new vessles
increase in type 1 fiber type, cappilary supply and myoglobin increases what
Together all of these changes act to lead to a dramatic increase in the maximal aerobic capacity compared to the very small change that you will see in VO2 max
When you stop training then you get less and less mitochondria but when you start training again you get those mitochondrai back therefore if you want to keep the no up then you need to keep training
what does this mean for competitive endurence athelats
An endurance competitions athletes will tapper their endurance exercise off so that there body has time to recover before the rase
This is important that they do this the relax up the muscles so they can work at the max intensity but the taper can’t be too long before the race or you get into the detraining mode
what is detraining mode
loss of mitochondria in the muscle fibers
what is the best way to taper your excersize before an endurance competition
75% 2 weeks out
50% one week out and then only short sharp sessions the week of so you don’t detain the week of
how does the lung addapt with excercise
O2 moves into alveoli -> into RBC (Hg) -> into tissues
The respiratory muscles get stronger
- stronger diaphragm, intercostals = greater amount of oxygen inhaled- TIDAL VOLUME
More capillaries around alveoli
hypertrophy of inspiratory muscles and increase in capillary lead to…..
increased VO2 max
exercise training allows you to increases VO2 max to what
excersize intensity
- normal = 12km/hour
- trained = 16km/hour
VO2 max
normal = 45mL/Kg/min
trained = 58mL/Kg/min
what does an increase in VO2 max mean
increases their O2 carrying capacity = ability to metabolises glucose and carbohydrates form longer
VO2 max increases with endurance training. what else does
lactate threshold meaning that you can stay in aerobic for longer
This is because we can use the carbs/glucose and fats much better because we have better metabolic capacity because of the increase in mitochondria as well as the facts that we can get more O2 into the capiliaries beds
lactic acid can also be combusted at a greater rate
how is lactic acid able to be used for energy
Lactic acid can be converted into pyruvate and then converted into acetyl CoA, decreasing lactic acids conc meaning you can go longer
why is the increase in VO2 max very small compared to the aerobic capacity increase
VO2 max is dependent on your muscle type, age, body time, lung capacity, ect.
most of these are anatomical that you will get from your genetic makeup therefore cant change
how long will it take with training to reach Highest possible VO2max
Highest possible VO2max achieved after 12 to 18 months
• finite VO2max range determined by genetics, training alters VO2max within that range
what % of VO2 max is determined by genetics
• accounts for 25 to 50% of variance in VO2max
do males or females have a higher VO2 max
• trained females < trained male
Two females, one 24 years old and one 55-years
old, with the same body mass and same VO2max of 40ml/kg/min both run on a regular basis. If they were
to both run at a 10 min per km pace, who would be
expected to have a higher heart rate?
- A. The 24-year old
- B. The 55-year old
- C. The heart rates should be equivalent
A because HR decreases with age
