Integration 1 Flashcards
What is meant by “endurance exercise”?
Exercise that is performed for a prolonged period of time
What are examples of endurance exercise?
Long distance running (anywhere from 5km to a marathon)
Road cycling or mountain biking
What 4 main physiological system work together for endurance exercise?
The cardiovascular system, respiratory system, nervous system, and the musculoskeletal system
What is Vo2Max?
A measure of the maximal rate of O2 consumption per minute
What is the most common measure for cardiorespiratory fitness?
Vo2max
What makes fit trained athletes have a more efficient physiological system?
Greater vo2max meaning they can deliver more oxygen to working muscles and extract more oxygen per unit of time so that they can perform at faster speeds.
How does Vo2max differ between males and females?
Men have a higher Vo2max in most sports than women
Does cricket or a marathon athletes have higher VO2 Max?
Marathon - sports that require more endurance (longer length of continued exercise) have higher Vo2 Max?
How does vo2max change as we age?
It decreases
What is an individuals Vo2max primarily due to?
Genetics (as high as 50% of the initial vo2 Max value is determined by genetics)
How much can vo2 max be improved by with training?
Approx 30%
What determines how much Vo2 Max can change as a result of training?
Genetics
What are the four ways that training can improve Vo2 Max?
Respiratory pulmonary diffusion (bring in more oxygen)
Muscle capacity to extract O2 from circulating RBC
Maximal cardiac output (amount of blood leaving heart) can be increased
Increased blood capacity to transport O2 (due to increase in Hb)
How does muscle capacity change from at rest to during intense aerobic exercise?
During intense aerobic exercise more capillaries are perfused therefore they are able to extract more oxygen per 100ml of blood and therefore less oxygen is left in venous blood.
What are RBC responsible for?
Transporting O2 from our lungs to the muscles
What is haemoglobin molecules in RBC responsible for?
Binding O2 and later releasing it
What is the hematocit percentage in adult males?
41-50%
What is the hematocit percentage in adult females?
36-46%
What is a pulse oximetry?
A method to measure blood oxygen saturation. It does this by passing light and measuring the colour of blood which is determined by oxygen saturation
How does the oxygen saturation curve (ODC) differ between males and females with exercise and why?
There is a stronger right shift in males than in females. This is because males have a greater increase in body temperature and produce more lactic acid with exercise than females.
The shift to the left also differs ad females show significantly lower Hb-O2 affinity.
There is no difference after Vo2max exercise.
As much as […] ml of oxygen can be bound for each 100 ml of blood?
20ml
How does altitude training increase RBC?
Low O2 levels triggers the body to increase RBC numbers to capture more O2.
In order for altitude training to have a benefit on an individual how high do you need to be for how long?
2000-2500 meters for 3 weeks
What is blood doping?
The injection of RBC from a donor or your own previously removed RBC or the injection of EPO.
The increase in RBC allows muscles to work longer and harder without cramping.
What is EPO used clinically for?
To treat individuals with anemia
Explain the movement of O2 from blood to muscle cell:
O2 moves from the high concentration in blood to a low concentration in the muscle cell
What is the O2 gradient between blood and muscle cell generated by?
Generated by the oxidation of O2 in muscle cells by the energy-generating mitochondria.
What is the effect of having more mitochondria in the muscles?
It means that more O2 can b used and therefore the more O2 that muscle can extract because of a greater diffusion gradient.
Does mitochondria increase with training?
Yes (x2)
How is an increase in mitochondria sustained?
By sustained training - if you stop training levels will fall but then if you start training they can increase again
What is the bodies two main sources of energy?
Lipids (fat) and glucose (carbohydrate)
Where is fat stored in the body?
Adipose tissue
Where is glucose stored in the body?
In the liver as glycogen
Where does oxidative phosphorylation take place?
Mitochondria
What source of energy does the body use at rest and low to moderate intensities (e.g., below 60% of maximal oxygen uptake)?
Lipids = fats
What is the main substrate for generating ATP during high intensity exercise (+75%)?
Glucose (carbohydrates)
What can shift the crossover point between fats and carbs towards higher exercise intensities?
Training
When you training your high intensity threshold of when carbohydrates are used is pushed up.
What are necessary factors in oxidation phosphorylation?
Oxygen consumption and carbon dioxide
What is the difference between anaerobic and aerobic energy?
Anaerobic = breaking down glucose without using oxygen = shorter higher intensity exercise = leads to a build up of lactic acid.
Aerobic = breaking down carbohydrates and fats in the presence of oxygen = continuous movement fuelled by the air you breathe = better for endurance exercise.
What is RER the abbreviation for?
Respiratory Exchange Ratio (or the respiratory quotient = RQ).
What does the RER describe?
The ratio of the rate of CO2 release to oxygen consumption.
Vco2/Vo2
What does the amount of oxygen used during metabolism depend on?
The type of fuel being oxidised
Is more oxygen need for the metabolism of fat or glucose and why?
Fat - because the amount of oxygen needed is proportional to the amount of carbon
If the RER is close to 1 what does that tell us?
That glucose is the major fuel source
If RER is less than 1 what does that tell us?
That fats are the major fuel source
What is the store of immediate energy?
Creatinine
What is the faster production of energy between creatinine and fat & glucose?
Creatinine
What is the phosphocreatine pathway?
The phosphocreatine (PCr) pathway is an energy system in the body that provides immediate energy for short bursts of high-intensity activities. It is one of the three primary energy systems, alongside the anaerobic and aerobic systems, but is the fastest to activate.
How much ATP is yielded for each PCr?
1
What is the maximum duration of exercise the PCr can supply?
approximately 3-15 seconds
What does the PCr pathway recycle during exercise?
PCr can recycle ADP/ATP during exercise until it is used up
Is oxygen required for the PCr pathway?
No
What are the 4 sources of ATP generation?
ATP-PCr
Anaerobic: Glycolysis
Aerobic:
Oxidation from carbohydrates
Oxidative from fat
What sources of ATP generate the most ATP?
Aerobic (although they take more time they produce more molecules).
What source of ATP generation has the greatest available capacity?
Oxidative aerobic from fat (days)
What is the chemical reaction for glycolysis?
Glucose or glycogen to lactate
What is the chemical reaction for aerobic oxidative from carbohydrates?
Glucose or glycogen to CO2 and H2O
What is the chemical reaction for aerobic oxidative from fats?
Free fatty acids or triglycerides to CO2 and H2O
Are anaerobic and aerobic exercise seperate?
No - anaerobic exercise always accompanies aerobic exercise.
Is the anaerobic or aerobic system activated first?
Anaerobic (lactic acid system)
What are the muscle fibres types?
Type I
Type II (a and x)
Describe type I muscle fibres:
Type 1 muscle fibres are slow twitch meaning they have a slow response to peak tension.
They are slow oxidative meaning they depend on fat and glucose energy sources.
What is the difference between Type 2 A and X muscle fibres?
Type 2A = fast oxidative.
Type 2X = Fast glycolytic.
Type 2A primarily use aerobic (and some anaerobic glycolysis) whereas X primarily use anaerobic glycolysis.
A have intermediate rate of fatigue whereas X have fast fatigue rate.
A also have intermediate glycogen stores whereas X have higher glycogen stores.
What are type 2 muscle fibres?
Fast twitch fibres = respond fast = peak tension is shorter (fatigue quicker)
What is the genetic link percentage for muscles fibres?
Approx 50%
Can training shift your muscle fibres or are they 100% determined by genetics?
Only 50% is determined by genetics - training can switch between type 2 subtypes of muscle fibres (but not between type 1 and 2)
What is the effect of early life sports on muscle fibre types?
Involvement in early life sports can influence adult levels of muscle types
What are the two ways to determine muscle fibre types?
Muscle biopsy (invasion and limited sample area)
Magnetic resonance spectroscopy (noninvasive, measures carnosine - metabolite 2 times higher in fats twitch fibres)
What is the recruitment order of muscle fibre types?
First = Type 1
Second = Type 2A
Third = Type 2X
What is significant about Alberto Salazar?
He was the best marathon runner in the 1980s but had a very high VO2max which showed that Vo2max is not the only parameter important to athletes…
What is lactate threshold?
The point at which blood lactate begins to substantially accumulate above resting concentrations during exercise of increasing intensity (aka as glycolysis or anaerobic production of ATP begins to dominate).
It is where blood lactate first appears to increase disproportionally above resting values.
Is lactate threshold before or after aerobic threshold?
After
What is the benefit of low zone training for endurance athletes?
Low zone training is low intensity training.
It is beneficial because it can raise your lactate threshold (shift it to the right) which means that it delays fatigue when exercising.
This happens as a result of using energy coming primarily from fat burning allowing the body to use a more sustainable fuel source for long durations and preserving glycogen stores.
What is EPOC?
EPOC = excess post-exercise oxygen consumption
EPOC is the result of an elevation in oxygen consumption and metabolism, which occurs after exercise as the body recovers, repairs, and returns to its pre-exercise state.
= after intense exercise it takes several minutes after exercise for oxygen consumption to reach resting O2 consumption levels. EPOC is just the nam used for this lay period.
What is the equation for cardiac output (CO)?
CO = HR x SV
What is resting CO?
5L / Min
What happens to HR when you exercise?
It increases
(So does CO)
What is the relationship between HR and SV?
Inversely proportional (therefore if CO increases HR increases and SV decreases).
As intensity of exercise increases what happens to HR?
It increases proportionally
What is maximum HR?
The highest HR value achieved in an all-out effort to the point of fatigue
How does age effect HR max?
HR max decreases with age - predictable decrease of about one beat per year beginning at 10 to 15 years of age.
When does HR plateau?
At very high intensity
What can HR max be estimated based on?
Age (subtracting your age from 220 beats/min gives a approximate HR max)
What is steady-rate HR?
Steady Rate HR refers to the plateau reached when exercise intensity is held constant at any sub maximal workload. The plateau is a result of your heart rate stabilising and remaining consistent - at this point the cardiovascular system is efficient in meeting the bodies demands for oxygen. Oxygenated blood is provided to the muscle bed based on the level of activity of the muscle.
How long after exercise can steady state HR be met?
2-3 minutes (as the intensity gets stronger it takes longer).
What is Steady State HR a measure of?
Endurance capacity - a well trained athlete will be able to reach and sustained steady state HR more easily without overworking the heart because they can extract more oxygen and so do not have to increase HR to the same level in order to met the greater intensity.
Why is steady-state training helpful using running as an example?
By incorporating steady-state running sessions at a moderate intensity at 60–70% of your max heart rate (MHR) over time your heart becomes more efficient, allowing you to maintain a lower steady-state HR.
Having a lower steady-state HR means that there is less work load on the heart and therefore surplus energy to be used else where and means that you reach your HR max at a higher intensity than before = better endurance
Training at high intensity primarily engages your anaerobic system whereas low to moderate intensity training primarily engages your aerobic system meaning it is training the body to efficiently use oxygen to produce energy - the better the body can do this better the body can handle endurance exercise. High intensity training should be used to complement low-moderate intensity training in order to increase speed/Vo2max/lactate threshold.
Where do parasympathetic nerve endings concentrate?
In the Atria, including the SA and AV nodes.
What do sympathetic fibres supply?
The SA and AV nodes and the muscle of atria and ventricles.
Explain the anticipatory effect of exercise?
The anticipation of exercising stimulates the AV node and increases your HR
When we exercise does BP increase?
Exercise increases BP (initial increase is greater and then it subsides or goes back to normal)
What is the short term control of MABP?
The arterial baroreceptor reflex
What are baroreceptors located?
Aortic arch and carotid sinus
How are signals from bararorecptors transmitter to the brain?
Via vagus and glossopharyngeal nerves
Where do vagus and glossopharyngeal nerves transmit signals from baroreceptors to?
To the nucleus of the solitary tract = NTS
Located in the medulla oblongata
Explain the baroreceptor reflex mechanism:
Baroreceptors detect changes in BP
Signals transmitted to the NTS
NTS baroreceptive cells process and initiate response - either stimulating a decrease or increase in sympathetic nervous activity.
If increase BP it decreases sympathetic nervous activity. If decreases it stimulates CVLM and RVLM.
How much can CO increase during exercise?
Can increase from 5L/min to 20L/min
What leads to vasodilation during exercise?
Vasodilation due to local metabolic factors in skeletal and cardiac muscles and the release of vasodilators by contracting skeletal muscles
How does the recruitment of capillaries increase blood flow during exercise?
Increases the total surface area for diffusion and shortens the diffusion distance
What is vasodilations and sweating during exercise caused by??????
The increase in sympathetic cholinergic fibre activity to skin resistance vessels (causes sweating)
and
The decrease in sympathetic vasoconstrictors drive to artery venous anastomosis in extremities (causes vasodilations)
What are the three main goals of the respiratory system during exercise?
(1) Ensure that partial pressures of O2 in our arteries are well maintained to allow adequate O2 supply to exercising muscles
(2) To eliminate metabolic and non-metabolic CO2 to maintain the partial pressure of CO2 in our arteries
(3) To assist in the buffering of metabolic acids produced during high intensity exercise
What are the metabolic sources of CO2 (equations)?
Glucose + 6 O2 = 6 Co2
Palmitate + 23 O2 = 16 Co2
What is the non-metabolic equation for CO2?
H+ + HCO3 = H2CO3 = CO2
What is the relationship between ventilation vs workload (intensity)?
There is a linear increase in ventilation until it reaches a threshold and then become exponential.
Linear represents aerobic and exponential represents anaerobic.
Showing you need to increase ventilation in order to bring in more oxygen to increase intensity.
Why does mouth ventilation increase with intensity?
Because of increased tidal volume (because more muscles become engaged) and increased respiratory rate
What changes occur when expiration becomes an active process?
Abdominal muscles contract
Internal intercostal muscles contract
Diaphragm pushes up = increases pressures = forced air flow out
What are the relative speeds of ATP production for aerobic and anerobic types of production?
Anaerobic Glycolysis = fastest rate of ATP production - but limited stores of glycogen and produces lactic acid.
Aerobic Fat Oxidative Phosphorylation = Slowest = used at low intensity endurance - unlimited stores.
Aerobic CHO Oxidative Phosphorylation = faster than Fat = used at high intensity endurance - but limited stores.
*Hence why we want to improve Fat OP threshold and efficiency so that we can use it for longer before using up CHO stores and if we can make it more efficient then can use it at higher intensities before triggers switch to CHO.
