Exercise Physiology Flashcards
Fill in the blanks. Resting heart rate Tends to _______ with age and with increased cardiovascular fitness
DECREASE!!
True or False? In response to acute exercise, Heart rate (HR), stroke volume (SV), and cardiac output (Q) increase.
TRUE!!
How can one calculate their maximum heart rate?
HRmax = 220 – age in years
What is maximum heart rate?
The highest heart rate value one can achieve in an all-out effort to the point of exhaustion
What is the maximum heart rate that should be achieved?
85%
What happens to your heart rate as exercise intensity increases?
There is a LINEAR INCREASE as your VO 2 max increases.
True or False? As exercise intensity increases, the heart rate increases until you reach your Vo2 max.
TRUE!!
When is heart rate plateau reached?
During constant rate of submaximal work
True or False? The lower the steady-state heart rate, the more efficient the heart.
TRUE!!
What is a determinant of cardiorespiratory endurance capacity at maximal rates of work?
Stroke Volume
True or False? Stroke volume has a linear increase during acute exercise.
FALSE!! Stroke Volume does NOT have a linear increase.
What are the main reasons for increased stroke volume during exercise?
- Frank- Starling mechanism - More blood in the ventricle causes it to stretch more and contract with more force.
- Increased ventricular contractility (without end-diastolic volume increases)
- Decreased total peripheral resistance due to increased vasodilation of blood vessels to active muscles
What is the resting value of cardiac output?
5.0 L/min.
What is the cardiac output for high intensity exercise in the Average Person?
20-40 L/min or 15- 20 L/min
Fill in the blanks. “ When exercise intensity exceeds 60%, a further increase in Q(cardiac output is more as a result of an increase in _____ rather than ______.
More as a result of an increase in Heart rate than Stroke volume
At what time does Cardiovascular Drift normally occur during exercise?
After 20 mins of exercise
What is Cardiovascular Drift?
Cardiovascular drift is the result of decreased stroke volume, increased heart rate, and decreased systemic and pulmonary arterial pressure due to prolonged steady-state exercise or exercise in the heat.
When does Cardiovascular Drift normally occur?
Occurs with steady-state prolonged exercise or exercise in a hot environment
Which component of Blood Pressure increases in direct proportion to increased exercise intensity?
Systolic Blood Pressure
Resistance Exercise can exaggerate Blood pressure to as high as what reading?
480/350 mmHg
True or False? The brain gets more cardiac output during exercise.
FALSE!! It gets the same amount during rest and exercise .
Which part of the body gets majority of Cardiac Output during rest?
Digestive Tract ( Kidneys ,stomach, liver, intestines etc)
Which part of the body gets majority of Cardiac Output during maximal exercise?
Skeletal Muscles
True or False? Blood Plasma Volume is increased with the onset of exercise.
FALSE!! It is REDUCED as it goes to the interstitial fluid space.
Fill in the blanks. _______ tends to increase during high-intensity resistance training, due in part to the Valsalva maneuver.
Blood Pressure
What happens to the total peripheral resistance during moderate exercise?
The PR is DECREASED, this is because there is vasodilation of arterioles in skeletal muscles.
True or False? During moderate exercise the blood flow to visceral organs are DECREASED because of vasoconstriction in the digestive tract due to sympathetic stimulation.
TRUE!!
What is the name of the Enzyme that is able to able to release the energy stored in the bond between adenosine diphosphate (ADP) and inorganic phosphate (Pi)?
ATPase
Skeltal muscles stores of which substance provide quantitatively the greatest contribution to energy provision in the first 10 seconds of high intensity activities such as sprinting?
Phosphocreatine
Slow twitch muscle fibres are what kind of muscle fibres?
Type I
Fast twitch muscle fibres are what kind of muscle fibres?
Type II
Way II ( too) fast
True or False? Slow twitch fibres have a low oxidative capacity.
FALSE!! Slow twitch fibres have a high oxidative capacity
Fill in the blanks. “ Slow twitch fibres are ___________ while fast twitch fibres are easily _______.
Slow twitch fibres are fatigue resistant while fast twitch fibres are easily fatigued.
Fill in the blanks .’ Fast twitch fibres have ______ contractile speed, _____ oxidative capacity, are _____fatigued, and have ______ glycolytic capacity, relatively _____ blood flow capacity, ________capillary density, and ______ mitochondrial content.
Fast contractile speed
Low oxidative capacity
Easily fatigued
High glycolytic capacity
Low blood flow capacity
Low capillary density
Low mitochondrial content .
Only has High glycolytic activity and fast contractile speed - everything else is low!
What type of athletes have slow twitch fibres?
Long- distance athletes
What type of athletes have fast- twitch fibres ?
Sprinters
Which muscle fibre type has a low glycolytic activity, high capillary density and high blood flow capacity?
Slow- Twitch
True or False? During exercise, as oxygen consumption increases the volume of carbon dioxide produced also increases.
TRUE!!
What is a minor increase in breathing rate before exercise known as?
An anticipatory rise.
When exercise begins, there is an immediate and greater increase in breathing rate due to receptors in the muscles and joints , this is by what action?
Neural control
When oxygen consumption increases, the volume of carbon dioxide produced also increases. This stimulates the respiratory centre to increase breathing rate , this is known as?
Chemical control
What happens to the breathing rate after exercise?
Breathing returns to normal – rapidly at first, and then more slowly.
During exercise , what happens to the internal intercostal muscles ?
They contract during expiration moving the ribs and sternum upwards and outwards forcibly.
What happens when the abdominal muscles also contract during exercise?
It Increases the pressure of the abdominal cavity, helping the diaphragm to rise more forcibly.
What is Minute Volume ( VE)?
Minute volume is the volume of a gas inhaled per minute. During exercise it usually refers to oxygen intake per minute.
How is Minute Volume calculated?
Tidal Volume x Breathing rate ( L/min)
A person’s optimal level of fitness is represented by ?
VO2max
What is VO2 ?
VO2 is the volume of oxygen consumed per minute.
Fill in the blanks. “ ________ is considered the best estimate of a person’s cardiorespiratory fitness or aerobic power.”
VO2 max
What happens to the body after exercise?
After exercise there is hyperventilation, as the ‘oxygen debt’ resulting from build-up of metabolites, is cleared by incoming oxygen
What percentage of blood goes to the skeletal muscles during exercise?
About 86%
At rest, What percentage of blood goes to the muscles?
About 20%
Why does the Cardiac Output increase during exercise?
This is as a result of a rise in heart rate via sympathetic stimulation.
CO = SV x HR
Why does an anticipatory increase in heart rate occur?
This is due to activation of the sympathetic nervous system. Before exercise, the heart rate increases, raising cardiac output ahead of metabolic demand.
True or False? During Exercise, your tidal volume decreases.
FALSE!! During exercise , your tidal volume increases dramatically due to the body’s demand for more oxygen and/or the need to offload increased levels of carbon dioxide.
What is the ‘safe-zone’ for heart rate during exercise?
85% of HRmax.
What are key adaptations of long - term exercises?
The resting heart rate decreases while stroke volume increases.
How is blood pressure calculated?
Blood pressure is determined by the equation: BP = CO x PR - Cardiac Output x Peripheral resistance
True or False? During exercise , your blood pressure increases.
TRUE!! Increases in both CO and PR during exercise contribute to a steady rise in BP.
Why is there an increase in blood pressure during exercising?
Sympathetic nervous system activity causes cardiac output to rise. It also causes vasoconstriction of arteries, causing an increase in resistance to blood flow (PR).
What happens to the pulse rate during exercise?
The pulse rate rises and blood flow to the muscles increases.
What is the normal pH of blood?
The pH of blood is generally between 7.35 and 7.45
What happens to the pH of blood during exercise?
During exercise blood pH can decrease and become more acidic, as a result of the presence of waste products and metabolites such as carbon dioxide and lactic acid in the blood.
What is Arteriovenous oxygen difference (a−VO2 diff)?
Arteriovenous oxygen difference is the difference in the oxygen content between arterial and venous blood.
What happens to the Arteriovenous oxygen difference during exercise?
Exercise leads to an increase in this difference because, as exercise intensifies, the working muscle tissue demands more oxygen from the arterial blood, so the oxygen content of venous blood decreases.
What happens to the body’s core temperature during exercise?
The body temperature increase, During exercise muscular work is achieved by burning fuels such as carbohydrates and fats. This produces heat. As the muscles warm up, blood circulating through the muscles is also warmed resulting in a rise in the body’s core and peripheral temperatures.
What is the cardiovascular response to an increase in the body’s core temperature during exercise?
There may be a slight increase in Cardiac Output to help enhance blood flow to the skin to help to lose the extra heat produced by exercising.
What is Isocapnic buffering?
This occurs when the increased production of acid, the increased rate in ventilation and CO2 production remain proportional, so alveolar and arterial CO2 change relatively little.
What happens to the alveolar partial pressure as a response to hyperventilation?
Alveolar PO2 increases.
What is the stimulus for ventilation after exercise?
There will be elevated arterial H+ concentration due to the lactic acidemia
What is the magnitude of Oxygen debt?
The magnitude of the O2 debt is the amount by which O2 consumption exceeds basal consumption from the end of exertion until the O2 consumption has returned to preexercise basal levels.
What happens to the build up of lactic acid after exercise?
Eighty percent of the lactic acid is converted to glycogen and 20% is metabolized to CO2 and
H2O.
What happens during the repayment of Oxygen debt?
The O2 concentration in muscle myoglobin rises slightly. ATP and phosphorylcreatine are resynthesized, and lactic acid is removed.
True or False? The high-energy phosphate bond of phosphocreatine has more energy than the bond of ATP.
TRUE!!
What is the combined amounts of cell ATP and cell phosphocreatine called?
Phosphagen energy system
True or False? The energy from the phosphagen system is used for maximal short bursts of muscle power.
TRUE!!
What is the number of moles of ATP generated by the phopho-creatine system?
4 moles of ATP
During exercise , what substance causes extreme fatigue?
Build up of lactic acid
How can lactic acid be removed from the body?
1) A small portion of it is converted back into pyruvic acid and then metabolized oxidatively by the body tissues.
2) the remaining lactic acid is reconverted into glucose mainly in the liver, and the glucose in turn is used to replenish the glycogen stores of the muscles.
What is the normal oxygen body store?
2 L
Where are oxygen stores in the body located?
Lungs ( 0.5L)
Body fluids (0.25L)
Haemoglobin (1L)
Myoglobin in muscle fibres ( (0.3 L)
What is the normal amount of oxygen that must be repaid as oxygen debt?
11.5 L
What is the early portion of Oxygen debt called?
Alactacid oxygen debt and amounts to about 3.5 litres
What is the latter portion of oxygen debt called?
Lactic acid oxygen debt and amounts to about 8 liters.
By what ways , during exercise is ones aerobic energy capability is depleted?
1) oxygen debt
2) depletion of the glycogen stores of the muscles.
What is the recovery time of muscle glycogen for persons who consume a high-carbohydrates diet?
2 days
What is the recovery time of muscle glycogen for persons who consume a high - protein, high fat and no food at all?
Very little recovery even after 5 days
What are the nutrients used during muscle activity?
Carbohydrates
Fats ( in the form of fatty acids or acetoacetic acids)
Protein ( In the form of amino acids)
Why does continuous exercise results in muscle hypertrophy?
Muscle Hypertrophy results from increased diameter of the muscle fibers rather than increased numbers of fibers.
What are the changes that occur in a hypertrophied muscle?
- Increase number in myofibrils
- Increase in mitochondrial enzymes
3.Increase in the components of the phosphagen metabolic system, including both ATP and phosphocreatine. - Increased in store glycogen
5.Increase in stored fat
True or False? Slow- twitch fibres are about twice as large in diameter compared with fast-twitch fibers.
FALSE!! Fast -twitch fibres are largerrrr
Which muscle fibres have more mitochondria and myoglobin?
Slow- Twitch fibres
Which muscle is prone to having fast twitch fibres?
Gastrocnemius
Which muscle is more prone to having slow twitch fibres?
Soleus
What is normal oxygen consumption?
250ml/min
What is the most limiting factor for the delivery of oxygen to the muscles during maximal muscle aerobic metabolism?
The ability of the heart to pump blood to the muscles
What is the oxygen- diffusing capacity?
The oxygen- diffusing capacity is a measure of the rate at which oxygen can diffuse from the pulmonary alveoli into the blood.
What accounts for a greater increase in cardiac output during exercise?
Heart rate ( more than stroke volume)
At what body temperature is a person considered to be having a heat stroke?
41 - 42 degrees Celsius
What types of cells are more at risk when the body temperature rises during exercise / hot humid temperatures?
Brain cells
True or False? In the well-trained athlete the amount of heat liberated in the body is almost exactly proportional to the oxygen consumption.
TRUE!!
What is the best way to treat a heat stroke?
*Remove all clothing
*Maintain a spray of cool water on all surfaces of the body or continually sponge the body
*Blow air over the body with a fan.
What is the name of the hormone that has direct effect on the sweat glands, increasing reabsorption of sodium chloride from the sweat before the sweat issues forth from the sweat gland tubules onto the surface of the skin?
Aldosterone
Where is Aldosterone secreted?
From the Adrenal cortex
Why does body fitness and weight control greatly reduce cardiovascular diseases?
(1) Maintenance of moderately lower blood pressure
(2) Reduced blood cholesterol and low-density lipoprotein along with increased high-density lipoprotein
Why is it important to maintain physical activity in older persons?
To increase their respiratory reserves
True or False? In skeletal muscle , ATP is not stored in any appreciable quantities.
TRUE!!!
Fill in the blanks. A rise in metabolism depends on _____________?
- The cross bridge - cycling rate of myosin and actin
- Substrate availability
- Accumulation of metabolic byproducts
What percentage of ATP is produced by Aerobic metabolism at rest?
100%
Fill in the blanks. At rest “ 2/3 of fuel is contributed by _____ by ______ while 1/3 of fuel is contributed by ______ by ________.
2/3 - Fats by Beta Oxidation
1/3 - CHO by aerobic glycolysis
True or False? At rest your blood lactate levels are high .
FALSE!! They are low
What is Oxygen Deficit / Debt?
This is the period of exercise during which level of oxygen consumption is below necessary to supply all ATP required.
True or False? Trained individuals have a lower oxygen deficit.
TRUE!!
ATP and creatine phosphate ( CP) is what kind of energy source?
Alactic anaerobic source
Glucose from stored glycogen in the absence of oxygen is what kind of energy source ?
Lactic anaerobic source
Glucose, lipids and proteins in the presence of oxygen is what kind of source?
Aerobic source
How long is Alactic anaerobic sources maintained for?
8-10 seconds
What type of physical activities utilizes Alactic anaerobic sources?
Explosive sports’ - weightlifting, jumping , throwing, 100m running , shot put and 50m swimming
What type of physical activities utilises lactic anaerobic sources?
” Short intense sport ( less than 2 mins) Gymnastics, 200 to 1000 m running, 100 to 300 m swimming
What is the recovery time for lactic anaerobic sources?
1 to 2 h
What are the effects of lactic acid on the skeletal muscles?
↓ the rate of ATP hydrolysis
↓ efficiency of glycolytic enzymes
↓Ca2+ binding to troponin
↓ interaction between actin and myosin (muscle fatigue)
Where does lactate change back into pyruvate and by what process ?
In the liver - Gluconeogenesis
Fill in the blanks. During rest , Lactic acid is converted back to _____ and oxidised by _____.
Pyruvic acid and oxidised by skeletal muscles
What is the recovery time for activities that utilised that Aerobic source?
24-48 hours
What type of activities utilises the aerobic source?
Long sports - available after 2-4 mins of exercise
What organs are fuel aerobic sources stored in?
Muscles, Adipose tissue and liver
When is Aerobic respiration used?
After 2-4 minutes of exercise
When is Glycolysis used during exercise ?
After 8-10 seconds
What is Vo2 max?
It is the peak oxygen consumption that is influenced by age, sex and training level of person performing exercise.
What is the name that represents the plateau in peak oxygen consumption, reached during exercise involving a sufficiently large muscle mass ?
Maximal oxygen consumption
What is maximal oxygen consumption limited by?
The ability to deliver Oxygen to skeletal muscles and muscle oxidative capacity
During Oxygen Deficit/Debt, What is the primary fuel source initially?
Anaerobic systems
What is Oxygen Deficit?
It is the volume difference between an ideal and real oxygen uptake.
What is Oxygen debt?
It is the extra volume that is needed to store all energetic systems .
True or false? Untrained individuals have a higher oxygen deficit while trained individuals have a lower oxygen deficit.
TRUE!!
What is the unit for VO2 max?
mL/kg/min - VO2 max is measured in milliliters of oxygen used in one minute per kilogram of body weight (mL/kg/min).
What is Cardiac Output?
Cardiac Output is Strove Volume x Heart Rate
CO = SV x HR
What is the unit for Cardiac Output?
L/min
What happens to the End- Diastolic volume during exercise?
It increases
What factors regulate the ventilation recovery after exercise delay?
Blood pH
PCO2
Temperature
What is the equation for Fick’s principle?
CO= VO2 / AV difference ( oxygenated blood from tissues- deoxygenated blood from tissues )
Fill in the blanks. “ In relation to respiratory response to exercise, Light exercise ONLY increases ______ while heavy exercise increases _______ and _________.
Light exercise only increases Tidal volume.
Heavy exercise increases Tidal Volume and Respiratory Frequency/Rate
True or False? The increase in ventilation is proportional to the increase in O2 consumption.
TRUE!!
What are the two primary functions of the respiratory response to exercise?
1.Match oxygen (O2) intake to O2 consumption VO2.
2.Acid-Base Balance.
What happens to the pulse rate and blood flow during aerobic exercise?
They increase
What is Dynamic Exercise?
This is rhythmic cycles of contraction and relaxation; change in muscle length
What is Isometric (static) exercise ?
This occurs when there is constant muscle length and increased tension.
What type of muscle fibres are normally used in Anaerobic exercise?
Fast-twitch muscle fibers
Fill in the blanks. “ Slow twitch muscle fibres are _____ in colour while Fast - Twitch muscle fibres are _____ in colour.”
Slow- Red
Fast - White ( low in myoglobin )
” fast is a whitey a whiteyyyy ohhhh”
What are the energy sources for Anaerobic exercises?
Creatine phosphate + glycogen (glucose) from muscle
Which type of muscle fibres are used in Aerobic exercises?
Slow-twicth fibres
What are the energy sources for Aerobic exercises?
Glucose ( early)
Free fatty acids ( later)
What are the factors that influences peak oxygen consumption?
Sex, age and training level of the person performing the exercise.
What are the causes of muscle fatigue?
*Lactic acid
- ↓ATP (accumulation of ADP and Pi, and reduction of creatine phosphate) leads to Ca++ pumping and release to and from SR which leads to ↓ contraction and relaxation
- Ionic imbalances - muscle cell is less responsive to motor neuron stimulation
What percentage of maximal aerobic power output can fat support?
60%
What is the primary source for low intensity exercises?
Plasma FFA (fat from fat cells)
What are the systemic effects that occurs during anticipating exercise?
- Bronchodilation
- Intra muscular vasodilatation
- Visceral and skin vasoconstriction
- Increased cardiac output
What are the metabolic effects that occurs during anticipating exercise?
- Promotion of glycogenolysis and glycolysis in muscle
- Release of glucose from liver
- Release of free fatty acids from adipose tissue.
