Integration 2 Flashcards
What are characteristics of strength/resistance athletes?
High static component
Short duration
Immense power
Uses ATP store and ATP-CP system
What are characteristics of aerobic/endurance athletes?
High dynamic component
Long duration
Steady high intensity
Uses aerobic system
Why do active muscles have an increased requirement of oxygen during exercise?
Because muscles are using up ATP, there is an increased cardiac output and increased ventilation (plus more).
What makes exercise become easier over time?
System being made more efficient due to body adaptations to repeated exposure to the stress (remodelling)
What are the three key points about cardiac remodelling?
Increased heart mass
Reversible
No fibrosis
What is meant by there is “no fibrosis” in cardiac remodelling?
No scar tissue formation (when exposed to a stress some cells will die and be replaced with no fibrotic cells - this is favourable).
What is the physiological cardiac remodelling of an endurance athlete (e.g., runner / swimmer)?
Thickening of the LV walls
LV dilation
What is the physiological cardiac remodelling of a strength athlete (e.g., weightlifter, wrestler)?
Thickening of LV wall
Mild LV dilation
What is the physiological cardiac remodelling of a combination athlete?
Gross thickening of LV walls
LV dilation
What is a combination athlete?
An athlete that trains in both cardio and resistance training
E.g., rower or canoeist
Is physiological remodelling reversible?
Yes
What is concentric hypertrophy?
An increase in the size of cardiomyocytes due to an increase in the number of sarcomeres added in PARALLEL
(= inward increase in the size of cardiomyocytes meaning thicker wall reducing lumen size).
What is increased during concentric hypertrophy?
Increased CSA of muscle fibres (becomes broader)
Increases contractile strength of each individual cell
How is concentric hypertrophy and after load related?
Concentric hypertrophy is a result of afterload
Increased after load causes the heart, particularly the LV, to work harder to pump blood against this higher resistance.
This leads to increased wall stress, compensatory cardiac remodelling and thicker myocardium = concentric hypertrophy.
What is after load?
The ventricle wall tension developed to over aortic pressure.
Afterload refers to the pressure the heart must overcome to eject blood during systole (the contraction phase). It’s primarily determined by the resistance in the arteries (e.g., high blood pressure or conditions like aortic stenosis).
What type of training predominately causes concentric hypertrophy?
Resistance / Strength exercise training
How much can strength / resistance exercise training increase BP?
up to x3 increase = sudden elevations in BP
What does pressure overload cause?
Concentric Hypertrophy
What is eccentric hypertrophy?
Increased size of cardiomyocytes due to an increase number of sarcomeres added in SERIES (Z line to Z line).
= outward increase in the size of cardiomyocytes wall proportional to the increase in lumen size = elongation
What is increased by eccentric hypertrophy?
Increased contractile strength of each individual cell
What is preload?
Preload refers to the amount of stretch in the ventricular walls at the end of diastole, just before contraction. It is determined by the volume of blood returning to the heart. A higher blood volume increases the stretch on the heart’s walls, leading to greater preload.
Greater preload = greater EDV
How is preload and eccentric hypertrophy related?
Eccentric hypertrophy is a result of increased preload
How is volume overload induced?
By increasing preload
How does increased preload cause eccentric hypertrophy?
Passively stretches the cardiomyocytes putting stress on the proteins
Remodelling to elongates muscle fibres
Proportionally increased wall thickness to chamber dilation
What type of exercise predominantly results in eccentric hypertrophy?
Endurance/aerobic exercise training
(sustained high intensity and highly dynamic exercise)
How much can cardiac output be increased from 5-6Lmin during endurance / aerobic exercise training?
Up to around 40 L/min
What does volume overload with slight pressure overload cause?
Increase work of left ventricle
results in elongation of muscle fibres
Increased thickness of LV wall proportional to increased chamber diameter
How does chamber dilation increase SV?
With chamber dilation there is a larger EDV
A larger EDV increases SV
How does more sarcomeres result in a larger SV?
More sarcomeres increase the force of left ventricle therefore increased SV
How does training effect SV?
Trained athletes will have a greater SV than untrained athletes
What is an easy and non-invasive method of tracking training progress?
Using HR as a proxy for fitness
Lower HR indicates a higher level of aerobic fitness
What does watts measure?
A measure of power output.
A trained athlete will be able to perform at higher exercise intensity (produce more watts) before reaching their max HR.
E.g., In activities like cycling, watts measures the power applied to the pedals. The more watts a cyclist can sustain, the faster and more efficiently they can ride. For example, producing higher watts allows a cyclist to climb hills more easily, accelerate faster, and maintain higher speeds over time.
How does aerobic/endurance training affect max HR?
It doesn’t as max HR is determined by age - instead what it does is determine the intensity of exercise you can perform at your given max HR.
E.g., how many watts you can produce before reaching max HR
What are the vascular adaptation to aerobic exercise?
Reduced arterial stiffness and increased blood volume
What causes a reduction of arterial stiffness as a result of aerobic exercise?
A higher SV = larger expansion of the vessel wall = increased compliance enables better dampening of pulsatility (to ensure there is laminar flow).
What causes there to be an increase in blood volume as a result of aerobic exercise?
Increase in aldosterone and antidiuretic hormone release causing sodium reabsorption and water retention and Increase in plasma proteins = increased plasma volume.
Increase RBC count as well due to acute increase of erythropoietin release post-exercise
When is EPO released?
During acute periods after exercise
What are the 3 skeletal muscle adaptions to aerobic exercise?
Conversion of more Type 1 (slow twitch) fibres (fast to type1 or type2a intermediate)
Increased mitochondrial content within muscles fibres
Increase capillary density
What is the result of more type 1 fibres?
Increased number of oxidative enzymes
More myoglobin (oxygen storage)
What does increase mitochondrial content within muscle fibres result in?
oxygen consumption capacity because more ATP
How much can training increase mitochondrial content within a muscle fibre?
x2
What is VEGF?
Vascular Endothelial Growth Factor
What does athletes strategic tapering before an event have to do with mitochondrial content ?
Mitochondrial content reflects training status - because it increases and decrease with training. So whilst it is important for athletes to taper to ensure their bodies are fresh for an event this needs to be done strategically (e.g., not for too long or too far before event) otherwise they risk losing adaptations and their benefit.
What promotes angiogenesis?
An increase in vascular endothelial growth factor (VEGF) hormone causes angiogenesis which is the formation of new blood vessels
What is angiogenesis?
The production of blood vessels.
What are the structural changes to lungs/airways as a result of aerobic exercise?
There are none
what are the respiratory systems adaptations to aerobic exercise?
Stronger respiratory muscles
Increased pulmonary capillary density around alveoli
What causes an increase in lung capacity as a result of aerobic exercise?
Stronger respiratory muscles
How does aerobic exercise causes an increase in the SA for gas exchange?
The increase in pulmonary capillary density around alveoli means that there is an increase SA for gas exchange
How is Vo2-max improved in endurance (aerobic) athletes?
(1) Improved oxygen delivery to the tissues
(2) Improved oxygen uptake within skeletal muscles
How is oxygen delivery to tissues improved with endurance training?
increased cardiac output
increase number of RC
increased skeletal muscle capillary density
What is anaerobic threshold?
The threshold is the point when the body can no longer remove the lactic acid at a rate the body is producing it at
How is anaerobic threshold affected with endurance athletes?
The push the threshold higher - meaning it takes a higher exercise intensity (work rate/more watts) to reach the threshold
= improved endurance capacity
= worker harder for longer
How does oxidative phosphorylation in skeletal muscle become more efficient as a result of endurance training?
Because there is more mitochondria and oxidative enzymes it means that it works more efficiently
What is an example of an oxidative enzyme in skeletal muscle?
Lactate dehydrogenase