Work is defined as
force times distance.
Power is defined as
work divided by time.
The SI unit for work is the
joule
Calculate the power if 600 joules of work are completed in 60 seconds
10 watts
Calculating the work performed on a cycle ergometer requires that you know all of the following except
resistance against flywheel.
Direct calorimetry is a means of determining energy expenditure and involves the measurement of
heat production
The energy cost of horizontal running can be estimated reasonably accurately because
the VO2 increases linearly with running speed.
The most common technique used to measure oxygen consumption in exercise physiology laboratories is
open-circuit spirometry
A MET is defined as a metabolic equivalent and is equal to
resting VO2
Net efficiency is defined as
work performed/energy expended above rest times 100
Exercise efficiency is greater in subjects who
have a higher percentage of slow muscle fibers
Recent evidence suggests that the optimum speed of movement
increases as the power output increases
A subject performing a 10-MET activity would have an oxygen consumption of approximately
35 ml�kg -1�min -1.
The SI units used to describe power are
watts.
Net efficiency ______________ as work rate increases
decreases
Work equals power divided by time
false
The SI unit used for both work and energy is the joule.
true
One MET equals resting oxygen consumption, which is approximately 5.3 ml�kg-1�min-1
false
The term homeostasis is defined as
the maintenance of a constant internal environment
Physiologists use the term steady state to denote
a steady and unchanging level of a physiological variable
A series of interconnected components that serve to maintain a physical or chemical parameter of the body near a constant value is
a biological control system
The general components of a biological control system are the
receptor, integrating center, and effector.
Most control systems of the body operate via
negative feedback
The gain of a biological control system can be thought of as the
amount of amplification of the system or the precision with which the control system maintains homeostasis.
In negative feedback, the response of the system is
opposite to that of the stimulus
During 60 minutes of constant-load submaximal exercise, the body temperature reaches a plateau after 35-45 minutes. This is an example of
steady state.
The precision with which a control system maintains homeostasis is termed
gain
Stress proteins that are manufactured by cells in response to exercise
can help to repair damage caused by free radicals
Because of complex control systems, the body always maintains homeostasis, even during exercise
false
Which of the following is an example of positive feedback?
labor contractions during childbirth
Which of the following would occur in response to elevated blood glucose to maintain homeostasis?
increased uptake of glucose by cells
The effectors in the response to increased body temperature include
cutaneous blood vessels and sweat glands
The first law of thermodynamics states that energy
cannot be created nor destroyed
By definition, an endergonic reaction is
a chemical reaction that requires energy to be added to the reactants before the reaction will take place
Coupled reactions are defined as
reactions that are linked together, with the liberation of free energy in one reaction being used to drive the second reaction
Enzymes are catalysts that increase the rate of reactions by
lowering the energy of activation.
Elevated blood levels of lactate dehydrogenase may assist in the diagnosis of which medical condition?
myocardial infarction
Which of the following definitions describes the function of the "hydrolase" category of enzymes
enzymes that catalyze reactions in which the cleavage of bonds is accomplished by adding water
Stored polysaccharides in muscle and other tissues in animals are called
glycogen
Fats that are stored in muscle and adipose tissue that play an important role as an energy substrate are
triglycerides
The most important high-energy phosphate compound in the muscle cell is
ATP
The simplest and most rapid method of producing ATP during exercise is through
ATP-PC system.
Which of the following statements about glycolysis is correct?
glycolysis ends with the production of pyruvic acid or lactic acid
If muscle glycogen is the initial substrate, ATP can be produced via glycolysis.
3
The two most important hydrogen (electron) carriers in bioenergetic chemical reactions are
NAD and FAD
The primary function of the Krebs cycle is to
complete the oxidation of carbohydrates, fats, and proteins (i.e., form NADH and FADH).
Aerobic production of ATP occurs in the
mitochondria (i.e., electron transport chain) in a process called oxidative phosphorylation
Each pair of electrons passed through the electron transport chain from NADH to oxygen releases enough energy to form
2.5 ATP.
The total ATP production via aerobic breakdown of glucose is
32 ATP
The calculated efficiency for aerobic respiration is approximately
34%.
The breakdown of creatine phosphate is regulated by
ADP concentration in the cytoplasm
The most important rate limiting enzyme in glycolysis is
phosphofructokinase.
The rate limiting enzyme in the Krebs cycle is
isocitrate dehydrogenase
In general, the higher the intensity of the activity, the greater the contribution of
anaerobic energy production
A rate-limiting enzyme in the aerobic synthesis of ATP in the mitochondria is
isocitrate dehydrogenase.
The conversion of pyruvate to lactate requires
a. the enzyme LDH
b. NADH+H+
c. both of these
In order to be oxidized for the eventual formation of ATP, amino acids must first be broken down into proteins
false
The process of beta-oxidation involves
the breakdown of a fatty acid to acetyl-CoA
Once pyruvic acid has been converted to lactic acid, it cannot be turned back into pyruvic acid.
false
The enzyme-substrate complex is
best described by the lock and key model
The caloric (kcal) yield of one gram of protein is
4 kcal/g.
The enzyme responsible for catalyzing the immediate energy system is
creatine kinase
The accumulation of _________ would slow glycolysis by inhibiting its rate limiting enzyme.
ATP
The actual ATP yield from aerobic metabolism of one molecule of glucose is different from the theoretical yield because
it accounts for the fact that an additional H+ is required to move ATP into the cytoplasm
The shorter the activity, the the contribution of anaerobic energy sources
greater
The primary purpose of the Krebs cycle is to
complete the oxidation of foodstuffs using NAD and FAD as hydrogen (electron) carriers
Which of the following is true concerning the electron transport chain?
The electrons passed down the chain will eventually be used to help form water.
Body temperature increases slightly during exercise. This would have the effect of
denaturing enzymes.
At rest, the O2 consumption of a 70-kg young adult is approximately
a. 250 ml/min.
b. 0.25 L/min.
c. 3.5 ml/kg/min.
d. all of the above.
The first bioenergetic pathway to become active at the onset of exercise is
the ATP-Pc system
The term oxygen deficit refers to the
lag in oxygen consumption at the beginning of exercise
Energy to run a maximal 400-meter race (i.e., 50 to 60 seconds) comes from
a combination of aerobic/anaerobic metabolism, with most of the ATP coming from anaerobic sources.
Energy to run a 40-yard dash comes
almost exclusively from the ATP-CP system.
The energy to perform long-term exercise (i.e., >20 minutes) comes primarily from
aerobic metabolism
The lactate threshold is defined as the work rate or oxygen uptake at which there is a systematic
rise in blood levels of lactic acid
Which of the following factors may explain the rise in blood lactic acid at the lactate threshold?
both a and b
A respiratory quotient (RQ) of 0.95 during steady-state exercise is suggestive of a(n)
high rate of carbohydrate metabolism.
When calculating the RQ, protein is often ignored. Why?
because protein generally plays a small role as a substrate
Most of the carbohydrate (e.g., for a rested, well-fed athlete) used as a substrate during high-intensity exercise comes from
muscle glycogen stores
The process of breaking down triglycerides into free fatty acids and glycerol is called
lipolysis
Depletion of carbohydrate stores during exercise influences fat metabolism by
reducing the level of Krebs cycle intermediates
During the "rapid" portion of the oxygen debt (or EPOC), the excess VO2 is due to
restoration of muscle CP and blood and muscle oxygen stores
The oxygen debt is generally higher following heavy exercise when compared with light exercise because heavy exercise
results in greater body heat gained, greater CP depleted, higher blood levels of epinephrine and norepinephrine, and greater depletion of blood and muscle oxygen stores
Which of the following is true about VO2 during exercise?
VO2 increases linearly with work rate
Removal of lactic acid following a bout of intense exercise is
more rapid if the subject performs light exercise (~30% VO2 max), compared to rest.
The slow rise in oxygen uptake over time during high-intensity, prolonged exercise is due to
rising body temperature.
Trained individuals have a lower oxygen deficit; this may be due to
having a better developed aerobic bioenergetic capacity.
The primary fuel source during light-intensity (25% VO2 max) exercise is
plasma FFA.
The drift upward of VO2 during constant-load exercise in a hot environment is due to
a. rising blood levels of lactate.
increasing body temperature
Lactate is formed and accumulates when the rate of glycolytic production of pyruvate and NADH exceeds the rate at which these products are shuttled into the mitochondria
true
The RER can rise above 1.00
a. during high-intensity exercise.
b. if VCO2 > VO2.
c. when the buffering of lactic acid stimulates ventilation to blow off CO2.
d. when all of these occur.
The progressive increase in the percent energy from carbohydrates and a decrease in the percent energy from fat is called the
crossover concept
The respiratory exchange ratio equals the respiratory quotient during short-term maximal exercise.
false
The carbohydrate fuel source that becomes most important after 3-4 hours of moderate-intensity (~70% VO2 max) exercise is
blood glucose
Fat contains more energy per gram than carbohydrates; therefore, ATP can be produced more rapidly from fats than from carbohydrates
false
Trained individuals usually produce less lactate than untrained individuals when making the transition from rest to steady-state exercise
true
Lactic acid accumulation contributes to muscle fatigue during exercise and causes the muscle soreness that may occur 24-48 hours after exercising.
true
Which of the following is true concerning the Cori Cycle?
It is one means of decreasing (metabolizing) accumulated lactate.
The primary fuel source during high-intensity (85% VO2 max) exercise is
muscle glycogen.
The RQ for fat is
0.70
Which of the following conditions would result in a higher EPOC?
higher intensity of exercise
VO2 max is determined by
a. the maximum ability of the cardiorespiratory system to deliver oxygen to the muscle.
b. the ability of the muscle to take up and use oxygen to produce ATP.
c. both a and b.
Which of the following is true concerning VO2 max?
It is a valid measure of cardiovascular fitness
During moderate-intensity (65% VO2 max) exercise, the percent of ATP derived from carbohydrates is ___________ the percent ATP from fats.
equal to
The exercise intensity that promotes the greatest total grams of fat metabolized is
50% of VO2 max.
The exercise intensity at which blood levels reach four millimoles per liter is termed the onset of blood lactate accumulation (OBLA).
true
After the first few minutes of constant-load, submaximal exercise, VO2 reaches steady state, indicating that
the ATP demand is being met aerobically.
Anatomically, the nervous system can be divided into two main parts:
central nervous system and peripheral nervous system
Nerve fibers that conduct impulses away from the central nervous system are called
efferent.
Neurons can be divided into three basic parts:
cell body, dendrites, and axon.
Neurons are negatively charged on the inside of the cell with respect to the charge on the exterior of the cell. This electrical charge difference is called
resting membrane potential
The action potential is generated when a stimulus
opens sodium channels.
Nerve fibers that carry impulses toward the central nervous system are called
afferent fibers
The joint receptors that provide the central nervous system with information about body position are termed
proprioceptors.
The ______________________ is an organ located in the inner ear and is responsible for maintaining general equilibrium
vestibular apparatus
A "movement plan" is developed by the _________________ before being sent to spinal centers for modification
motor cortex
The motor cortex is concerned with voluntary movement and is located within the
cerebrum.
The area of the brain that aids in control of movement and may initiate fast ballistic movements is the
cerebellum
Voluntary movements are planned and executed by the motor cortex without outside influence from other areas of the nervous system
false
The autonomic nervous system can be divided into two functional and anatomical divisions called
sympathetic and parasympathetic
An excitatory neurotransmitter results in increased neuronal permeability to
sodium and results in EPSPs.
Parkinson's disease is a disorder of the basal ganglia resulting in
increased involuntary movement of tremors
The term kinesthesia refers to
conscious recognition of the position of body parts with respect to each other.
The spinal cord translated a voluntary movement into appropriate muscle action. This is called
spinal tuning
Neurotransmitters that cause depolarization of membranes are called
excitatory transmitters
The summing of many EPSPs from a single pre-synaptic neuron over a short time period is called
temporal summation.
Sympathetic neurons are motor neurons, and parasympathetic neurons are sensory neurons.
true
The initial drive to move comes from
subcortical and cortical areas.
______________ refers to the ability of a neuron to respond to a stimulus.
Irritability
Relative to brain health, regular aerobic exercise has been shown to
a. enhance learning and memory
b. improve brain blood flow
c. stimulate neuron formation
d. do all of the above.
Which of the following is true concerning neurons?
Maintaining resting membrane potential requires the use of energy from ATP
The neurotransmitter used in the parasympathetic nervous system is
acetylcholine
Equilibrium and balance require input from the
a. vestibular apparatus.
b. eyes.
c. joint, tendon, and muscle receptors.
d. all of the above.
Ans: d
The neurological disease that progressively destroys the myelin sheaths of axons in multiple areas of the CNS is
multiple sclerosis.
Muscle spindles provide sensory information relative to the
length of muscle.
The thin muscle cells located within the muscle spindle are called
intrafusal fibers.
The "knee jerk" or stretch reflex is due to the activation of the
muscle spindle
The Golgi tendon organs monitor
tension produced by muscular contraction.
The layer of connective tissue that surrounds the outside of skeletal muscle (i.e., just below the fascia) is called the
epimysium.
The cell membrane around muscle is called the
sarcolemma
The two principal contractile proteins found in skeletal muscle are
actin and myosin
Calcium is stored in muscle within the
sarcoplasmic reticulum.
The formation of cross-bridges in the contractile process in skeletal muscle is
calcium binding to troponin
A muscular contraction that results in a movement of body parts is called a(n
isotonic or dynamic contraction
Fast-twitch fibers contain a relatively
small number of mitochondria and high ATPase activity
The motor neuron and all the muscle fibers it innervates are called a motor
unit.
The site where the motor neuron and muscle cell meet is called the
neuromuscular junction
The breakdown of ATP in muscle is accomplished via the enzyme
ATPase.
Skeletal muscle fibers that contain large numbers of mitochondria and myoglobin could be classified as
either type I or type IIa
High activity of the enzyme ATPase is found in both slow-twitch and fast-twitch fibers.
false
A successful endurance athlete would likely have ________________ compared to a sedentary person.
a higher percentage of type I fibers
The amount of force exerted during muscular contraction is dependent on the
type of motor units recruited, the initial length of the muscle, and the nature of the neural stimulation.
Recent evidence suggests that rigorous exercise training can result in a conversion of muscle fiber type.
true
At any given velocity of movement, the peak force is greater in muscles that contain a high percentage of fast-twitch fibers when compared to muscles that possess predominantly slow-twitch fibers.
true
If you continue to increase the firing rate (of action potentials) of a motor neuron, then all of the skeletal muscle fibers it innervates will eventually summate to tetanus
true
Rigor mortis is caused by an inability of myosin to enter a weak binding state with actin
true
Muscle atrophy may be caused by a decrease in protein production, as well as an increase in protein degradation.
true
The change in muscle fiber type that would most likely occur as a result of endurance training is
type IIx to type IIa
Type IIx fibers
have high specific tension.
Which of the following events in muscle contraction is the first to occur chronologically?
The innervating alpha-motor neuron has an action potential
Which of the following events in muscle contraction is the last to occur chronologically?
Calcium is resequestered (taken up) into the sarcoplasmic reticulum
Which of the following has been shown to cause muscle fatigue
the accumulation H+
Satellite cells
are undifferentiated cells that play a key role in muscle growth and repair
During the initial period of disuse (i.e., 2 days), muscle atrophy is predominantly due to
decreased protein synthesis
The primary purpose of the cardiovascular system is to
deliver adequate amounts of oxygen and remove wastes from body tissues
In order to meet the increased oxygen demands of muscle during exercise, two major adjustments in blood flow must be made:
an increase in cardiac output and a redistribution of blood flow from inactive tissues to skeletal muscles.
All gas exchange between the vascular system and tissues occurs in
capillaries.
Backflow of blood from the arteries into the ventricles is prevented by the
semilunar valves
The muscle of the heart is referred to as the
myocardium.
Electrical impulses are conducted between heart muscle cells by
intercalated discs
Skeletal and cardiac muscle are similar in which of the following ways?
both muscles are composed of striated fibers containing actin and myosin
The contraction phase of the heart is called
systole.
In a healthy heart, the time spent in systole is generally
shorter than diastole
During exercise, the time spent in diastole and systole
is decreased, with the greatest decrease occurring in diastole
The difference between systolic and diastolic blood pressure is called the
pulse pressure.
The normal pacemaker of the heart is the
sinoatrial node
The __________ represents ventricular repolarization during a recording of the electrical activity (i.e., ECG) of the heart
T wave
Which of the following is a mechanism for increasing venous return during exercise?
venoconstriction
An increase in parasympathetic outflow to the heart results in
a decrease in HR
The cardiovascular control center is located in the
medulla oblongata.
The fact that an increase in end-diastolic ventricular volume increases the stroke volume of the heart is an illustration of the
Frank-Starling law of the heart
The increase in cardiac output that occurs during exercise is due to
both an increase in mean arterial pressure and a decrease in vascular resistance.
The most important variable that determines resistance to blood flow is
the diameter of the vessel.
The relationship between cardiac output and metabolic rate is
linear.
In most subjects, stroke volume continues to increase during incremental exercise up to approximately
40% of VO2 max.
The decrease in maximal heart rate with age in adults can be estimated via
HR max = 220 - age
Autoregulation of local blood flow is due to
local factors such as a decrease in PO2, an increase in PCO2, and potassium concentrations
In general, heart rate increases in direct proportion to the metabolic rate during exercise.
true
Most of the increase in mean arterial blood pressure that occurs during dynamic (isotonic) incremental exercise is due to
the increase in systolic blood pressure
At any level of oxygen consumption, heart rate and blood pressure are lower during leg work when compared with arm work
true
The central command theory of cardiovascular control states that the initial signal to the cardiovascular system at the beginning of exercise comes from higher brain centers.
true
A local increase in the adenosine concentration around arterioles would result in
vasodilation
The arterial-venous oxygen difference
increases as a function of exercise intensity
The relationship between oxygen uptake, cardiac output, and the arterial-venous oxygen difference is described mathematically by the
Fick equation
The metabolic demand of the heart can be estimated by
a. the rate-pressure product.
b. the double product.
c. multiplying heart rate by systolic blood pressure.
d. all of the above.
One reason the stroke volume increases during exercise is that skeletal muscle vasodilation decreases afterload
true
In order to maintain systemic blood flow, an increase in peripheral resistance would require an increase in blood pressure.
true
Exercise training helps the heart to resist permanent damage during a heart attack
true
Which of the following is the correct order of events pertaining to contraction of the left ventricle?
The bundle branches depolarize, the ventricle contracts, the ventricular pressure increases, the aortic volume increases.
Which of the following is true of the heart rate change during exercise?
the increase in HR is due only to PNS withdrawal followed by increasing SNS influence.
The greatest resistance to blood flow is in the
arterioles
Which of the following represents the correct order of events of the flow of blood after it leaves the left ventricle and before it returns to the right atrium?
Blood flows through the aorta, oxygen moves out of the capillaries, blood flows through the venules, blood enters the veins
Beta-adrenergic blocking medications
interfere with epinephrine and norepinephrine receptor function
Which of the following factors would serve to increase blood pressure?
systemic vasodilation.
The primary purpose of the pulmonary system is
to provide an interface for gas exchange
The term ventilation refers to the
mechanical process of moving air in and out of the lungs
The most important muscle of inspiration is/are the
diaphragm.
The volume of gas that reaches the respiratory zone (gas-exchange zone) of the lung is termed
alveolar ventilation.
According to Fick's law of diffusion, the rate of diffusion for a gas is greater when the surface area for diffusion is large and the "driving pressure" (i.e., partial pressure) between the two sides of tissue is high
true
In the standing position, blood flow to the base of the lung is ______________ blood flow to the apex.
greater than
Exercise-induced asthma would reduce airflow by
increasing airway resistance
Most of the O2 that is transported in the blood is in
the form of oxyhemoglobin.
In general, because of blood hemoglobin concentration differences, males transport less oxygen per unit of blood volume than females.
false
Myoglobin is a red pigment found in skeletal muscle that serves to
bicarbonate
An increase in alveolar ventilation serves to lower arterial PCO2 and increase blood pH
true
Ventilation may drift upward during constant-load submaximal exercise performed in a hot and humid environment due to
higher blood temperature
Exercise-induced hypoxemia that may occur in elite endurance athletes during heavy exercise is likely due to
a diffusion limitation secondary to a rapid red blood cell transit time
The respiratory control center is located in the
medulla oblongata
The carotid bodies are chemoreceptors that are sensitive to changes in arterial
pH, PCO2, and PO2
The ventilatory central chemoreceptors respond to changes in the
pH of cerebral spinal fluid.
A decrease in arterial PO2 below 70 mm Hg would likely result in
an increase in alveolar ventilation.
Under normal conditions, the partial pressure of oxygen in the alveoli is
100 mmHg.
The alinear rise in ventilation observed during incremental exercise (i.e., ventilatory threshold) is thought to be principally due to
a decrease in arterial pH
Activation of rectus abdominis muscles would result in
active expiration.
The ideal ventilation-perfusion ratio in the lung is 1.
true
Under normal conditions, the characteristics of arterial blood include
a. PO2 of 100 mmHg.
b. oxyhemoglobin saturation of 97-98%.
c. oxygen content of 20 ml O2 / 100 ml blood.
d. all of the above.
A by-product of anaerobic glycolysis in red blood cells that is thought to alter the O2-Hb dissociation curve is
2-3 DPG
During exercise at sea level, young, healthy untrained subjects generally maintain exercise arterial PO2 within
10-12 mm Hg of resting values.
An increase in blood temperature and a decrease in blood pH would result in _____________ in the oxyhemoglobin dissociation curve
a leftward shift
At a low PO2, myoglobin has _______________ affinity for O2 than hemoglobin
a higher
The intrapleural pressure is lower than the intrapulmonary pressure.
true
The pulmonary system may limit VO2 max only in elite endurance athletes
false
During exercise, more oxygen is unloaded from hemoglobin to the tissues than at rest
true
Mitochondrial PO2 is _____________ capillary
less than
The amount of air inspired and expired at rest is called
tidal volume
In a pulmonary function test, a FEV1/FVC ratio of 0.70 is
suggestive of airway obstruction
Which of the following is correct?
The PO2 at sea level is 159 mmHg.
Small changes in arterial PCO2 have a ______________ effect on ventilation compared to small changes in PO2.
greater
In response to exercise training, the normal lung
does not undergo measurable changes.
Which of the following statements about body temperature homeostasis is correct
Body temperature is a balance between heat loss and heat gain.
During exercise, body temperature is regulated by making adjustments in the amount of heat that is lost.
true
Heat production can be increased voluntarily through
exercise
The body's thermostat is located in the
hypothalamus
The principal means of heat loss at rest in a cool environment (20�C/low humidity) is via
radiation
The transfer of heat from the body into molecules of cooler objects in contact with its surface is called
conduction.
In general, at high environmental temperatures, the most important variable determining heat loss by evaporation is/are the
a. convective currents.
b. ambient temperature and relative humidity.
c. amount of exposed skin.
d. all of the above.
Which of the following could be a mechanism of heat gain in a hot environment?
radiation
The evaporation of 1,000 ml of sweat results in the loss of 1,000 kcal of
false
An increase in core temperature results in
cutaneous vasodilation.
In general, during exercise in a thermoneutral environment, the increase in core temperature is directly related to the exercise intensity
true
The primary adaptations that occur during heat acclimatization are
an increased plasma volume, earlier onset of sweating, and a higher sweat rate
Hypothermia is defined as a large
decrease in core (body) temperature
Individuals with a high percentage of body fat have an advantage over lean individuals in tolerance to cold
true
Cold acclimatization results in an improved ability to sleep in a cold environment.
true
Heat acclimatization occurs generally within
7 to 14 days.
Cold adaptation results in a reduction in the mean skin temperature at which shivering begins
true
A high percentage of body fat results in an increased ability to lose body heat during exercise
false
In response to a decrease in body temperature, the __________ initiates the release of norepinephrine, which increases the rate of cellular metabolism
posterior hypothalamus
Evaporation of one liter of sweat would result in the loss of ________ kcal of heat
580
Training in a cool environment while wearing warm clothing (e.g., sweats) promotes heat acclimatization.
true
The most accurate way to measure core body temperature is with a tympanic thermometer.
false
Which of the following is true of heat shock proteins?
They help the body tolerate heat stress
Exercise in the heat is associated with accelerated fatigue due to
a. increased muscle glycogen utilization.
b. increased free radical production.
c. increased lactate production.
d. all of the above.
The higher the relative humidity, the __________ the vapor pressure gradient between the skin and the environment
lower
During exercise ____________ of energy produced is released as heat
70-80% kcal
Dehydration that results in a loss of 1-2% of body weight is sufficient to impair exercise performance.
true
Compared to exercise in a cool environment, prolonged exercise in the heat
results in a more rapid onset of muscular fatigue.
The average VO2 max value for the young male sedentary population is
45 ml � kg -1 � min -1.
In order to achieve improvements in VO2 max, highly trained individuals may need to train at intensities of
95-100% VO2 max
Cross-sectional studies show that the cardiovascular variable responsible for the large variation in VO2 max in the normal population is maximal
stroke volume
Following training, if the increase in maximal cardiac output is balanced with a decrease in peripheral resistance, the mean arterial blood pressure will
remain the same.
In a "two-legged" maximal cycle ergometer test, if each leg were to vasodilate to the extent experienced in a one-legged VO2 max test, mean arterial blood pressure would fall below normal levels.
true
Following an endurance training program, the oxygen deficit is smaller when the subject does the same work task. This is due to
increases in the number of mitochondria and capillaries
The enhanced capacity of the trained muscle to use fatty acids as a fuel results in
decreased lactate formation.
b. decreased utilization of muscle glycogen.
c. sparing of blood glucose.
d. all of the above.
Which of the following training adaptations does not result in lower lactate production?
increased glycogen utilization.
Lactate removal is greater following an endurance training program because blood flow to muscle is decreased, and liver blood flow is increased at the same work rate
true
The changes in the heart rate and ventilatory responses to a fixed submaximal work rate are lower after an endurance training program. These changes are due primarily to changes in the
active skeletal muscles
In the first 10 weeks of a resistance training program, the gains in strength are due primarily to
neural adaptations
Research indicates that anyone can increase his or her VO2 max with training, yet a genetic predisposition is required to have a VO2 max comparable to that of an elite endurance athlete
true
Following endurance training, afterload decreases during maximal exercise because there is a decrease in sympathetic vasoconstrictor activity in the arterioles of the exercising muscles.
true
Following endurance training, maximal cardiac output during exercise is increased due to an increase in ventricular muscle tissue thickness.
false
The increase in the maximal a-vO2 difference is due to all of the following except.
an increase in hemoglobin.
Reducing the number of motor units required to perform an exercise task may reduce the heart rate and ventilation required to perform the task
true
Training that involves very high volumes and intensities of exercise may increase one's risk of developing an upper respiratory tract infection.
true
In terms of the factors that limit VO2 max, improvements elicited by endurance training generally first affect ____________, and then ___________ after several weeks/months
cardiac output; avO2 difference
Following endurance training, maximal stroke volume is enhanced by an increased
venous return.
The systematic process in which the volume and intensity of training are varied over time is
periodization.
The majority of evidence demonstrates that resistance training-induced muscle hypertrophy is the result of muscle fiber hyperplasia
false
Endurance training results in increased mitochondrial and capillary density in muscle but has no effect on muscle glycolytic capacity. This is an example of what training principle?
specificity
The increase in VO2 max following training is caused by an increase in
both maximal stroke volume and maximal a-vO2 difference
The initial decrease in VO2 max with detraining occurs because skeletal muscle adaptations (a-vO2 difference) are lost.
false
Work is defined as
force times distance.
Power is defined as
work divided by time.
The SI unit for work is the
joule
Calculate the power if 600 joules of work are completed in 60 seconds
10 watts
Calculating the work performed on a cycle ergometer requires that you know all of the following except
resistance against flywheel.
Direct calorimetry is a means of determining energy expenditure and involves the measurement of
heat production
The energy cost of horizontal running can be estimated reasonably accurately because
the VO2 increases linearly with running speed.
The most common technique used to measure oxygen consumption in exercise physiology laboratories is
open-circuit spirometry
A MET is defined as a metabolic equivalent and is equal to
resting VO2
Net efficiency is defined as
work performed/energy expended above rest times 100
Exercise efficiency is greater in subjects who
have a higher percentage of slow muscle fibers
Recent evidence suggests that the optimum speed of movement
increases as the power output increases
A subject performing a 10-MET activity would have an oxygen consumption of approximately
35 ml�kg -1�min -1.
The SI units used to describe power are
watts.
Net efficiency ______________ as work rate increases
decreases
Work equals power divided by time
FALSE
The SI unit used for both work and energy is the joule.
TRUE
One MET equals resting oxygen consumption, which is approximately 5.3 ml�kg-1�min-1
FALSE
The term homeostasis is defined as
the maintenance of a constant internal environment
Physiologists use the term steady state to denote
a steady and unchanging level of a physiological variable
A series of interconnected components that serve to maintain a physical or chemical parameter of the body near a constant value is
a biological control system
The general components of a biological control system are the
receptor, integrating center, and effector.
Most control systems of the body operate via
negative feedback
The gain of a biological control system can be thought of as the
amount of amplification of the system or the precision with which the control system maintains homeostasis.
In negative feedback, the response of the system is
opposite to that of the stimulus
During 60 minutes of constant-load submaximal exercise, the body temperature reaches a plateau after 35-45 minutes. This is an example of
steady state.
The precision with which a control system maintains homeostasis is termed
gain
Stress proteins that are manufactured by cells in response to exercise
can help to repair damage caused by free radicals
Because of complex control systems, the body always maintains homeostasis, even during exercise
FALSE
Which of the following is an example of positive feedback?
labor contractions during childbirth
Which of the following would occur in response to elevated blood glucose to maintain homeostasis?
increased uptake of glucose by cells
The effectors in the response to increased body temperature include
cutaneous blood vessels and sweat glands
The first law of thermodynamics states that energy
cannot be created nor destroyed
By definition, an endergonic reaction is
a chemical reaction that requires energy to be added to the reactants before the reaction will take place
Coupled reactions are defined as
reactions that are linked together, with the liberation of free energy in one reaction being used to drive the second reaction
Enzymes are catalysts that increase the rate of reactions by
lowering the energy of activation.
Elevated blood levels of lactate dehydrogenase may assist in the diagnosis of which medical condition?
myocardial infarction
Which of the following definitions describes the function of the "hydrolase" category of enzymes
enzymes that catalyze reactions in which the cleavage of bonds is accomplished by adding water
Stored polysaccharides in muscle and other tissues in animals are called
glycogen
Fats that are stored in muscle and adipose tissue that play an important role as an energy substrate are
triglycerides
The most important high-energy phosphate compound in the muscle cell is
ATP
The simplest and most rapid method of producing ATP during exercise is through
ATP-PC system.
Which of the following statements about glycolysis is correct?
glycolysis ends with the production of pyruvic acid or lactic acid
If muscle glycogen is the initial substrate, ATP can be produced via glycolysis.
3
The two most important hydrogen (electron) carriers in bioenergetic chemical reactions are
NAD and FAD
The primary function of the Krebs cycle is to
complete the oxidation of carbohydrates, fats, and proteins (i.e., form NADH and FADH).
Aerobic production of ATP occurs in the
mitochondria (i.e., electron transport chain) in a process called oxidative phosphorylation
Each pair of electrons passed through the electron transport chain from NADH to oxygen releases enough energy to form
2.5 ATP.
The total ATP production via aerobic breakdown of glucose is
32 ATP
The calculated efficiency for aerobic respiration is approximately
34%.
The breakdown of creatine phosphate is regulated by
ADP concentration in the cytoplasm
The most important rate limiting enzyme in glycolysis is
phosphofructokinase.
The rate limiting enzyme in the Krebs cycle is
isocitrate dehydrogenase
In general, the higher the intensity of the activity, the greater the contribution of
anaerobic energy production
A rate-limiting enzyme in the aerobic synthesis of ATP in the mitochondria is
isocitrate dehydrogenase.
The conversion of pyruvate to lactate requires
a. the enzyme LDH
b. NADH+H+
c. both of these
In order to be oxidized for the eventual formation of ATP, amino acids must first be broken down into proteins
FALSE
The process of beta-oxidation involves
the breakdown of a fatty acid to acetyl-CoA
Once pyruvic acid has been converted to lactic acid, it cannot be turned back into pyruvic acid.
FALSE
The enzyme-substrate complex is
best described by the lock and key model
The caloric (kcal) yield of one gram of protein is
4 kcal/g.
The enzyme responsible for catalyzing the immediate energy system is
creatine kinase
The accumulation of _________ would slow glycolysis by inhibiting its rate limiting enzyme.
ATP
The actual ATP yield from aerobic metabolism of one molecule of glucose is different from the theoretical yield because
it accounts for the fact that an additional H+ is required to move ATP into the cytoplasm
The shorter the activity, the the contribution of anaerobic energy sources
greater
The primary purpose of the Krebs cycle is to
complete the oxidation of foodstuffs using NAD and FAD as hydrogen (electron) carriers
Which of the following is true concerning the electron transport chain?
The electrons passed down the chain will eventually be used to help form water.
Body temperature increases slightly during exercise. This would have the effect of
denaturing enzymes.
At rest, the O2 consumption of a 70-kg young adult is approximately
a. 250 ml/min.
b. 0.25 L/min.
c. 3.5 ml/kg/min.
d. all of the above.
The first bioenergetic pathway to become active at the onset of exercise is
the ATP-Pc system
The term oxygen deficit refers to the
lag in oxygen consumption at the beginning of exercise
Energy to run a maximal 400-meter race (i.e., 50 to 60 seconds) comes from
a combination of aerobic/anaerobic metabolism, with most of the ATP coming from anaerobic sources.
Energy to run a 40-yard dash comes
almost exclusively from the ATP-CP system.
The energy to perform long-term exercise (i.e., >20 minutes) comes primarily from
aerobic metabolism
The lactate threshold is defined as the work rate or oxygen uptake at which there is a systematic
rise in blood levels of lactic acid
Which of the following factors may explain the rise in blood lactic acid at the lactate threshold?
both a and b
A respiratory quotient (RQ) of 0.95 during steady-state exercise is suggestive of a(n)
high rate of carbohydrate metabolism.
When calculating the RQ, protein is often ignored. Why?
because protein generally plays a small role as a substrate
Most of the carbohydrate (e.g., for a rested, well-fed athlete) used as a substrate during high-intensity exercise comes from
muscle glycogen stores
The process of breaking down triglycerides into free fatty acids and glycerol is called
lipolysis
Depletion of carbohydrate stores during exercise influences fat metabolism by
reducing the level of Krebs cycle intermediates
During the "rapid" portion of the oxygen debt (or EPOC), the excess VO2 is due to
restoration of muscle CP and blood and muscle oxygen stores
The oxygen debt is generally higher following heavy exercise when compared with light exercise because heavy exercise
results in greater body heat gained, greater CP depleted, higher blood levels of epinephrine and norepinephrine, and greater depletion of blood and muscle oxygen stores
Which of the following is true about VO2 during exercise?
VO2 increases linearly with work rate
Removal of lactic acid following a bout of intense exercise is
more rapid if the subject performs light exercise (~30% VO2 max), compared to rest.
The slow rise in oxygen uptake over time during high-intensity, prolonged exercise is due to
rising body temperature.
Trained individuals have a lower oxygen deficit; this may be due to
having a better developed aerobic bioenergetic capacity.
The primary fuel source during light-intensity (25% VO2 max) exercise is
plasma FFA.
The drift upward of VO2 during constant-load exercise in a hot environment is due to
a. rising blood levels of lactate.
increasing body temperature
Lactate is formed and accumulates when the rate of glycolytic production of pyruvate and NADH exceeds the rate at which these products are shuttled into the mitochondria
TRUE
The RER can rise above 1.00
a. during high-intensity exercise.
b. if VCO2 > VO2.
c. when the buffering of lactic acid stimulates ventilation to blow off CO2.
d. when all of these occur.
The progressive increase in the percent energy from carbohydrates and a decrease in the percent energy from fat is called the
crossover concept
The respiratory exchange ratio equals the respiratory quotient during short-term maximal exercise.
FALSE
The carbohydrate fuel source that becomes most important after 3-4 hours of moderate-intensity (~70% VO2 max) exercise is
blood glucose
Fat contains more energy per gram than carbohydrates; therefore, ATP can be produced more rapidly from fats than from carbohydrates
FALSE
Trained individuals usually produce less lactate than untrained individuals when making the transition from rest to steady-state exercise
TRUE
Lactic acid accumulation contributes to muscle fatigue during exercise and causes the muscle soreness that may occur 24-48 hours after exercising.
TRUE
Which of the following is true concerning the Cori Cycle?
It is one means of decreasing (metabolizing) accumulated lactate.
The primary fuel source during high-intensity (85% VO2 max) exercise is
muscle glycogen.
The RQ for fat is
0.7
Which of the following conditions would result in a higher EPOC?
higher intensity of exercise
VO2 max is determined by
a. the maximum ability of the cardiorespiratory system to deliver oxygen to the muscle.
b. the ability of the muscle to take up and use oxygen to produce ATP.
c. both a and b.
Which of the following is true concerning VO2 max?
It is a valid measure of cardiovascular fitness
During moderate-intensity (65% VO2 max) exercise, the percent of ATP derived from carbohydrates is ___________ the percent ATP from fats.
equal to
The exercise intensity that promotes the greatest total grams of fat metabolized is
50% of VO2 max.
The exercise intensity at which blood levels reach four millimoles per liter is termed the onset of blood lactate accumulation (OBLA).
TRUE
After the first few minutes of constant-load, submaximal exercise, VO2 reaches steady state, indicating that
the ATP demand is being met aerobically.
Anatomically, the nervous system can be divided into two main parts:
central nervous system and peripheral nervous system
Nerve fibers that conduct impulses away from the central nervous system are called
efferent.
Neurons can be divided into three basic parts:
cell body, dendrites, and axon.
Neurons are negatively charged on the inside of the cell with respect to the charge on the exterior of the cell. This electrical charge difference is called
resting membrane potential
The action potential is generated when a stimulus
opens sodium channels.
Nerve fibers that carry impulses toward the central nervous system are called
afferent fibers
The joint receptors that provide the central nervous system with information about body position are termed
proprioceptors.
The ______________________ is an organ located in the inner ear and is responsible for maintaining general equilibrium
vestibular apparatus
A "movement plan" is developed by the _________________ before being sent to spinal centers for modification
motor cortex
The motor cortex is concerned with voluntary movement and is located within the
cerebrum.
The area of the brain that aids in control of movement and may initiate fast ballistic movements is the
cerebellum
Voluntary movements are planned and executed by the motor cortex without outside influence from other areas of the nervous system
FALSE
The autonomic nervous system can be divided into two functional and anatomical divisions called
sympathetic and parasympathetic
An excitatory neurotransmitter results in increased neuronal permeability to
sodium and results in EPSPs.
Parkinson's disease is a disorder of the basal ganglia resulting in
increased involuntary movement of tremors
The term kinesthesia refers to
conscious recognition of the position of body parts with respect to each other.
The spinal cord translated a voluntary movement into appropriate muscle action. This is called
spinal tuning
Neurotransmitters that cause depolarization of membranes are called
excitatory transmitters
The summing of many EPSPs from a single pre-synaptic neuron over a short time period is called
temporal summation.
Sympathetic neurons are motor neurons, and parasympathetic neurons are sensory neurons.
TRUE
The initial drive to move comes from
subcortical and cortical areas.
______________ refers to the ability of a neuron to respond to a stimulus.
Irritability
Relative to brain health, regular aerobic exercise has been shown to
a. enhance learning and memory
b. improve brain blood flow
c. stimulate neuron formation
d. do all of the above.
Which of the following is true concerning neurons?
Maintaining resting membrane potential requires the use of energy from ATP
The neurotransmitter used in the parasympathetic nervous system is
acetylcholine
Equilibrium and balance require input from the
a. vestibular apparatus.
b. eyes.
c. joint, tendon, and muscle receptors.
d. all of the above.
Ans: d
The neurological disease that progressively destroys the myelin sheaths of axons in multiple areas of the CNS is
multiple sclerosis.
Muscle spindles provide sensory information relative to the
length of muscle.
The thin muscle cells located within the muscle spindle are called
intrafusal fibers.
The "knee jerk" or stretch reflex is due to the activation of the
muscle spindle
The Golgi tendon organs monitor
tension produced by muscular contraction.
The layer of connective tissue that surrounds the outside of skeletal muscle (i.e., just below the fascia) is called the
epimysium.
The cell membrane around muscle is called the
sarcolemma
The two principal contractile proteins found in skeletal muscle are
actin and myosin
Calcium is stored in muscle within the
sarcoplasmic reticulum.
The formation of cross-bridges in the contractile process in skeletal muscle is
calcium binding to troponin
A muscular contraction that results in a movement of body parts is called a(n
isotonic or dynamic contraction
Fast-twitch fibers contain a relatively
small number of mitochondria and high ATPase activity
The motor neuron and all the muscle fibers it innervates are called a motor
unit.
The site where the motor neuron and muscle cell meet is called the
neuromuscular junction
The breakdown of ATP in muscle is accomplished via the enzyme
ATPase.
Skeletal muscle fibers that contain large numbers of mitochondria and myoglobin could be classified as
either type I or type IIa
High activity of the enzyme ATPase is found in both slow-twitch and fast-twitch fibers.
FALSE
A successful endurance athlete would likely have ________________ compared to a sedentary person.
a higher percentage of type I fibers
The amount of force exerted during muscular contraction is dependent on the
type of motor units recruited, the initial length of the muscle, and the nature of the neural stimulation.
Recent evidence suggests that rigorous exercise training can result in a conversion of muscle fiber type.
TRUE
At any given velocity of movement, the peak force is greater in muscles that contain a high percentage of fast-twitch fibers when compared to muscles that possess predominantly slow-twitch fibers.
TRUE
If you continue to increase the firing rate (of action potentials) of a motor neuron, then all of the skeletal muscle fibers it innervates will eventually summate to tetanus
TRUE
Rigor mortis is caused by an inability of myosin to enter a weak binding state with actin
TRUE
Muscle atrophy may be caused by a decrease in protein production, as well as an increase in protein degradation.
TRUE
The change in muscle fiber type that would most likely occur as a result of endurance training is
type IIx to type IIa
Type IIx fibers
have high specific tension.
Which of the following events in muscle contraction is the first to occur chronologically?
The innervating alpha-motor neuron has an action potential
Which of the following events in muscle contraction is the last to occur chronologically?
Calcium is resequestered (taken up) into the sarcoplasmic reticulum
Which of the following has been shown to cause muscle fatigue
the accumulation H+
Satellite cells
are undifferentiated cells that play a key role in muscle growth and repair
During the initial period of disuse (i.e., 2 days), muscle atrophy is predominantly due to
decreased protein synthesis
The primary purpose of the cardiovascular system is to
deliver adequate amounts of oxygen and remove wastes from body tissues
In order to meet the increased oxygen demands of muscle during exercise, two major adjustments in blood flow must be made:
an increase in cardiac output and a redistribution of blood flow from inactive tissues to skeletal muscles.
All gas exchange between the vascular system and tissues occurs in
capillaries.
Backflow of blood from the arteries into the ventricles is prevented by the
semilunar valves
The muscle of the heart is referred to as the
myocardium.
Electrical impulses are conducted between heart muscle cells by
intercalated discs
Skeletal and cardiac muscle are similar in which of the following ways?
both muscles are composed of striated fibers containing actin and myosin
The contraction phase of the heart is called
systole.
In a healthy heart, the time spent in systole is generally
shorter than diastole
During exercise, the time spent in diastole and systole
is decreased, with the greatest decrease occurring in diastole
The difference between systolic and diastolic blood pressure is called the
pulse pressure.
The normal pacemaker of the heart is the
sinoatrial node
The __________ represents ventricular repolarization during a recording of the electrical activity (i.e., ECG) of the heart
T wave
Which of the following is a mechanism for increasing venous return during exercise?
venoconstriction
An increase in parasympathetic outflow to the heart results in
a decrease in HR
The cardiovascular control center is located in the
medulla oblongata.
The fact that an increase in end-diastolic ventricular volume increases the stroke volume of the heart is an illustration of the
Frank-Starling law of the heart
The increase in cardiac output that occurs during exercise is due to
both an increase in mean arterial pressure and a decrease in vascular resistance.
The most important variable that determines resistance to blood flow is
the diameter of the vessel.
The relationship between cardiac output and metabolic rate is
linear.
In most subjects, stroke volume continues to increase during incremental exercise up to approximately
40% of VO2 max.
The decrease in maximal heart rate with age in adults can be estimated via
HR max = 220 - age
Autoregulation of local blood flow is due to
local factors such as a decrease in PO2, an increase in PCO2, and potassium concentrations
In general, heart rate increases in direct proportion to the metabolic rate during exercise.
TRUE
Most of the increase in mean arterial blood pressure that occurs during dynamic (isotonic) incremental exercise is due to
the increase in systolic blood pressure
At any level of oxygen consumption, heart rate and blood pressure are lower during leg work when compared with arm work
TRUE
The central command theory of cardiovascular control states that the initial signal to the cardiovascular system at the beginning of exercise comes from higher brain centers.
TRUE
A local increase in the adenosine concentration around arterioles would result in
vasodilation
The arterial-venous oxygen difference
increases as a function of exercise intensity
The relationship between oxygen uptake, cardiac output, and the arterial-venous oxygen difference is described mathematically by the
Fick equation
The metabolic demand of the heart can be estimated by
a. the rate-pressure product.
b. the double product.
c. multiplying heart rate by systolic blood pressure.
d. all of the above.
One reason the stroke volume increases during exercise is that skeletal muscle vasodilation decreases afterload
TRUE
In order to maintain systemic blood flow, an increase in peripheral resistance would require an increase in blood pressure.
TRUE
Exercise training helps the heart to resist permanent damage during a heart attack
TRUE
Which of the following is the correct order of events pertaining to contraction of the left ventricle?
The bundle branches depolarize, the ventricle contracts, the ventricular pressure increases, the aortic volume increases.
Which of the following is true of the heart rate change during exercise?
the increase in HR is due only to PNS withdrawal followed by increasing SNS influence.
The greatest resistance to blood flow is in the
arterioles
Which of the following represents the correct order of events of the flow of blood after it leaves the left ventricle and before it returns to the right atrium?
Blood flows through the aorta, oxygen moves out of the capillaries, blood flows through the venules, blood enters the veins
Beta-adrenergic blocking medications
interfere with epinephrine and norepinephrine receptor function
Which of the following factors would serve to increase blood pressure?
systemic vasodilation.
The primary purpose of the pulmonary system is
to provide an interface for gas exchange
The term ventilation refers to the
mechanical process of moving air in and out of the lungs
The most important muscle of inspiration is/are the
diaphragm.
The volume of gas that reaches the respiratory zone (gas-exchange zone) of the lung is termed
alveolar ventilation.
According to Fick's law of diffusion, the rate of diffusion for a gas is greater when the surface area for diffusion is large and the "driving pressure" (i.e., partial pressure) between the two sides of tissue is high
TRUE
In the standing position, blood flow to the base of the lung is ______________ blood flow to the apex.
greater than
Exercise-induced asthma would reduce airflow by
increasing airway resistance
Most of the O2 that is transported in the blood is in
the form of oxyhemoglobin.
In general, because of blood hemoglobin concentration differences, males transport less oxygen per unit of blood volume than females.
FALSE
Myoglobin is a red pigment found in skeletal muscle that serves to
bicarbonate
An increase in alveolar ventilation serves to lower arterial PCO2 and increase blood pH
TRUE
Ventilation may drift upward during constant-load submaximal exercise performed in a hot and humid environment due to
higher blood temperature
Exercise-induced hypoxemia that may occur in elite endurance athletes during heavy exercise is likely due to
a diffusion limitation secondary to a rapid red blood cell transit time
The respiratory control center is located in the
medulla oblongata
The carotid bodies are chemoreceptors that are sensitive to changes in arterial
pH, PCO2, and PO2
The ventilatory central chemoreceptors respond to changes in the
pH of cerebral spinal fluid.
A decrease in arterial PO2 below 70 mm Hg would likely result in
an increase in alveolar ventilation.
Under normal conditions, the partial pressure of oxygen in the alveoli is
100 mmHg.
The alinear rise in ventilation observed during incremental exercise (i.e., ventilatory threshold) is thought to be principally due to
a decrease in arterial pH
Activation of rectus abdominis muscles would result in
active expiration.
The ideal ventilation-perfusion ratio in the lung is 1.
TRUE
Under normal conditions, the characteristics of arterial blood include
a. PO2 of 100 mmHg.
b. oxyhemoglobin saturation of 97-98%.
c. oxygen content of 20 ml O2 / 100 ml blood.
d. all of the above.
A by-product of anaerobic glycolysis in red blood cells that is thought to alter the O2-Hb dissociation curve is
2-3 DPG
During exercise at sea level, young, healthy untrained subjects generally maintain exercise arterial PO2 within
10-12 mm Hg of resting values.
An increase in blood temperature and a decrease in blood pH would result in _____________ in the oxyhemoglobin dissociation curve
a leftward shift
At a low PO2, myoglobin has _______________ affinity for O2 than hemoglobin
a higher
The intrapleural pressure is lower than the intrapulmonary pressure.
TRUE
The pulmonary system may limit VO2 max only in elite endurance athletes
FALSE
During exercise, more oxygen is unloaded from hemoglobin to the tissues than at rest
TRUE
Mitochondrial PO2 is _____________ capillary
less than
The amount of air inspired and expired at rest is called
tidal volume
In a pulmonary function test, a FEV1/FVC ratio of 0.70 is
suggestive of airway obstruction
Which of the following is correct?
The PO2 at sea level is 159 mmHg.
Small changes in arterial PCO2 have a ______________ effect on ventilation compared to small changes in PO2.
greater
In response to exercise training, the normal lung
does not undergo measurable changes.
Which of the following statements about body temperature homeostasis is correct
Body temperature is a balance between heat loss and heat gain.
During exercise, body temperature is regulated by making adjustments in the amount of heat that is lost.
TRUE
Heat production can be increased voluntarily through
exercise
The body's thermostat is located in the
hypothalamus
The principal means of heat loss at rest in a cool environment (20�C/low humidity) is via
radiation
The transfer of heat from the body into molecules of cooler objects in contact with its surface is called
conduction.
In general, at high environmental temperatures, the most important variable determining heat loss by evaporation is/are the
a. convective currents.
b. ambient temperature and relative humidity.
c. amount of exposed skin.
d. all of the above.
Which of the following could be a mechanism of heat gain in a hot environment?
radiation
The evaporation of 1,000 ml of sweat results in the loss of 1,000 kcal of
FALSE
An increase in core temperature results in
cutaneous vasodilation.
In general, during exercise in a thermoneutral environment, the increase in core temperature is directly related to the exercise intensity
TRUE
The primary adaptations that occur during heat acclimatization are
an increased plasma volume, earlier onset of sweating, and a higher sweat rate
Hypothermia is defined as a large
decrease in core (body) temperature
Individuals with a high percentage of body fat have an advantage over lean individuals in tolerance to cold
TRUE
Cold acclimatization results in an improved ability to sleep in a cold environment.
TRUE
Heat acclimatization occurs generally within
7 to 14 days.
Cold adaptation results in a reduction in the mean skin temperature at which shivering begins
TRUE
A high percentage of body fat results in an increased ability to lose body heat during exercise
FALSE
In response to a decrease in body temperature, the __________ initiates the release of norepinephrine, which increases the rate of cellular metabolism
posterior hypothalamus
Evaporation of one liter of sweat would result in the loss of ________ kcal of heat
580
Training in a cool environment while wearing warm clothing (e.g., sweats) promotes heat acclimatization.
TRUE
The most accurate way to measure core body temperature is with a tympanic thermometer.
FALSE
Which of the following is true of heat shock proteins?
They help the body tolerate heat stress
Exercise in the heat is associated with accelerated fatigue due to
a. increased muscle glycogen utilization.
b. increased free radical production.
c. increased lactate production.
d. all of the above.
The higher the relative humidity, the __________ the vapor pressure gradient between the skin and the environment
lower
During exercise ____________ of energy produced is released as heat
70-80% kcal
Dehydration that results in a loss of 1-2% of body weight is sufficient to impair exercise performance.
TRUE
Compared to exercise in a cool environment, prolonged exercise in the heat
results in a more rapid onset of muscular fatigue.
The average VO2 max value for the young male sedentary population is
45 ml � kg -1 � min -1.
In order to achieve improvements in VO2 max, highly trained individuals may need to train at intensities of
95-100% VO2 max
Cross-sectional studies show that the cardiovascular variable responsible for the large variation in VO2 max in the normal population is maximal
stroke volume
Following training, if the increase in maximal cardiac output is balanced with a decrease in peripheral resistance, the mean arterial blood pressure will
remain the same.
In a "two-legged" maximal cycle ergometer test, if each leg were to vasodilate to the extent experienced in a one-legged VO2 max test, mean arterial blood pressure would fall below normal levels.
TRUE
Following an endurance training program, the oxygen deficit is smaller when the subject does the same work task. This is due to
increases in the number of mitochondria and capillaries
The enhanced capacity of the trained muscle to use fatty acids as a fuel results in
decreased lactate formation.
b. decreased utilization of muscle glycogen.
c. sparing of blood glucose.
d. all of the above.
Which of the following training adaptations does not result in lower lactate production?
increased glycogen utilization.
Lactate removal is greater following an endurance training program because blood flow to muscle is decreased, and liver blood flow is increased at the same work rate
TRUE
The changes in the heart rate and ventilatory responses to a fixed submaximal work rate are lower after an endurance training program. These changes are due primarily to changes in the
active skeletal muscles
In the first 10 weeks of a resistance training program, the gains in strength are due primarily to
neural adaptations
Research indicates that anyone can increase his or her VO2 max with training, yet a genetic predisposition is required to have a VO2 max comparable to that of an elite endurance athlete
TRUE
Following endurance training, afterload decreases during maximal exercise because there is a decrease in sympathetic vasoconstrictor activity in the arterioles of the exercising muscles.
TRUE
Following endurance training, maximal cardiac output during exercise is increased due to an increase in ventricular muscle tissue thickness.
FALSE
The increase in the maximal a-vO2 difference is due to all of the following except.
an increase in hemoglobin.
Reducing the number of motor units required to perform an exercise task may reduce the heart rate and ventilation required to perform the task
TRUE
Training that involves very high volumes and intensities of exercise may increase one's risk of developing an upper respiratory tract infection.
TRUE
In terms of the factors that limit VO2 max, improvements elicited by endurance training generally first affect ____________, and then ___________ after several weeks/months
cardiac output; avO2 difference
Following endurance training, maximal stroke volume is enhanced by an increased
venous return.
The systematic process in which the volume and intensity of training are varied over time is
periodization.
The majority of evidence demonstrates that resistance training-induced muscle hypertrophy is the result of muscle fiber hyperplasia
FALSE
Endurance training results in increased mitochondrial and capillary density in muscle but has no effect on muscle glycolytic capacity. This is an example of what training principle?
specificity
The increase in VO2 max following training is caused by an increase in
both maximal stroke volume and maximal a-vO2 difference
The initial decrease in VO2 max with detraining occurs because skeletal muscle adaptations (a-vO2 difference) are lost.
FALSE