Exercise Physiology

1. Work is defined as
A. the ability to transform energy from one state to another.
B. the ability to utilize oxygen.
C. force times distance.
D. distance times power output.
1. Power is defined as
A. the ability to perform work.
B. work divided by time.
C. work times force.
D. force times distance.
1. The SI unit for work is the
A. joule.
B. watt.
C. kpm.
D. kcal.
1. Calculate the power if 600 joules of work are completed in 60 seconds.
A. 10 watts
B. 660 watts
C. 36,000 watts
D. Power cannot be calculated with the information provided.
1. Calculating the work performed on a cycle ergometer requires that you know all of the following except
A. subject's body weight.
B. resistance against flywheel.
C. pedaling speed.
D. exercise time.
1. Direct calorimetry is a means of determining energy expenditure and involves the measurement of
A. oxygen consumption.
B. heat production.
C. ATP hydrolysis.
D. carbon dioxide production.
1. The energy cost of horizontal running can be estimated reasonably accurately because
A. the VO2 of running is always the same.
B. the VO2 of horizontal running is always 1 MET.
C. the VO2 increases linearly with running speed.
D. none of the above.
1. The most common technique used to measure oxygen consumption in exercise physiology laboratories is
A. closed-circuit spirometry.
B. open-circuit spirometry.
C. direct calorimetry.
D. computer calorimetry.
1. A MET is defined as a metabolic equivalent and is equal to
A. resting VO2.
B. 50% of resting VO2.
C. 200% of resting VO2.
D. VO2 max.
1. Net efficiency is defined as
A. work output/energy expended at rest times 100.
B. work performed/energy expended above rest times 100.
C. work output/energy expended times 100.
D. energy expended/work output times 100.
1. Exercise efficiency is greater in subjects who
A. have a higher percentage of fast muscle fibers.
B. have a higher percentage of slow muscle fibers.
C. have 50% fast fibers and 50% slow fibers.
1. Recent evidence suggests that the optimum speed of movement
A. increases as the power output increases.
B. decreases as the power output increases.
C. remains constant as the power output increases.
D. increases as the power output decreases.
1. A subject performing a 10-MET activity would have an oxygen consumption of approximately
A. 10 mlkg-1min-1.
B. 25 mlkg-1min-1.
C. 35 mlkg-1min-1.
D. 45 mlkg-1min-1.
1. The SI units used to describe power are
A. Newtons.
B. joules.
C. watts.
D. joules per second.
1. Net efficiency ______________ as work rate increases.
A. increases
B. does not change
C. decreases
1. A kilocalorie is equal to
A. 100 calories.
B. 1,000 calories.
C. 4,186 kilojoules.
D. 4.186 joules.
1. A runner who exhibits poor running economy would require
A. a lower VO2 at any given running speed compared to an economical runner.
B. a higher VO2 at any given running speed compared to an economical runner.
C. the same VO2 at any given running speed compared to an economical runner.
1. Work equals power divided by time.
1. The SI unit used for both work and energy is the joule.
1. One MET equals resting oxygen consumption, which is approximately 5.3 mlkg-1min-1.
1. The term homeostasis is defined as
A. a constant metabolic demand placed upon the body.
B. the maintenance of a constant internal environment.
C. a low metabolic rate.
D. a change within the internal environment.
1. Physiologists use the term steady state to denote
A. a steady and unchanging level of a physiological variable.
B. a completely normal external environment.
C. a changing internal environment.
D. an increase in body heat storage.
2. A series of interconnected components that serve to maintain a physical or chemical parameter of the body near a constant value is
A. homeostasis.
B. steady state.
C. a biological control system.
D. an organ system.
1. The general components of a biological control system are the
A. receptor, control center, and response.
B. receptor, control center, and effector.
C. effector, remote control, and stimulus.
D. receptor and integrating center.
1. Most control systems of the body operate via
A. positive feedback.
B. low-gain receptors.
C. negative feedback.
D. feed forward mechanisms.
1. The gain of a biological control system can be thought of as the
A. amount of amplification of the system or the precision with which the control system maintains homeostasis.
B. ratio of the amount of abnormality to the amount of correction needed to maintain a constant internal environment (i.e., amount abnormality/amount of correction needed).
C. positive feedback needed to maintain homeostasis.
D. stimulus that triggers the biological control system to bring the internal environment back to normal.
1. In negative feedback, the response of the system is
A. to increase the gain of the receptor.
B. to modify the receptor's response to the stimulus.
C. opposite to that of the stimulus.
D. to enhance the stimulus.
1. During 60 minutes of constant-load submaximal exercise, the body temperature reaches a plateau after 35-45 minutes. This is an example of
A. homeostasis.
B. effector.
C. steady state.
D. changing internal environment.
1. The precision with which a control system maintains homeostasis is termed
A. positive feedback.
B. negative feedback.
C. set point.
D. gain.
1. Stress proteins that are manufactured by cells in response to exercise
A. can lead to an increased production of free radicals.
B. can lead to further disruptions in homeostasis.
C. can lead to an increased degree of cellular injury.
D. can help to repair damage caused by free radicals.
1. Which of the following is an example of positive feedback?
A. regulation of blood glucose
B. regulation of body temperature
C. labor contractions during childbirth
D. the cellular stress protein response
1. Which of the following would occur in response to elevated blood glucose to maintain homeostasis?
A. decreased insulin secretion from the pancreas
B. increased uptake of glucose by cells
C. continued elevation of blood glucose
D. all of the above
1. The effectors in the response to increased body temperature include
A. cutaneous blood vessels and sweat glands.
B. cutaneous blood vessels and skeletal muscle.
C. baroreceptors.
D. stretch receptors.
1. A chemical messenger is released from one cell that stimulates nearby cells is an example of
A. autocrine signaling.
B. endocrine signaling.
C. juxtacrine signaling.
D. paracrine signaling.
1. Endocrine signaling involves the release of _________ into the bloodstream.
A. heat shock proteins
B. neurotransmitters
C. hormones
D. transcription factors
1. In protein synthesis, the formation of mRNA is called
A. transcription.
B. translation
1. Translation is the production of a protein from mRNA at the
A. nucleus.
B. ribosome.
C. mitochondria.
D. Golgi apparatus.
1. Because of complex control systems, the body always maintains homeostasis, even during exercise.
1. The first law of thermodynamics states that energy
A. cannot be created nor destroyed.
B. cannot be stored.
C. cannot be converted into other forms.
D. transformations result in an increase in entropy.
2. By definition, an endergonic reaction is
A. a chemical reaction that requires energy to be added to the reactants before the reaction will take place.
B. a chemical reaction that gives off energy.
C. an enzyme-catalyzed reaction.
D. a chemical reaction that results in products containing less free energy than the original reactants.
. Coupled reactions are defined as
A. reactions that are linked together via the same enzyme.
B. reactions that are linked together, with the liberation of free energy in one reaction being used to drive the second reaction.
C. reactions that are not directly linked together but are related to the same enzyme.
D. reactions that are linked via common substrates.
4. Enzymes are catalysts that increase the rate of reactions by A. pulling two substrates together.
B. lowering the energy of activation.
C. binding to a substrate and producing energy.
D. binding to a substrate and releasing protons.
. Elevated blood levels of lactate dehydrogenase may assist in the diagnosis of which medical condition?
A. Paget's disease
B. pancreatitis
C. muscular dystrophy
D. myocardial infarction
. Which of the following definitions describes the function of the "hydrolase" category of enzymes?
A. enzymes that catalyze reactions that result in the rearrangement of the structure of molecules
B. enzymes that catalyze reactions in which groups of elements are removed to form a double bond or are added to an existing double bond
C. enzymes that catalyze reactions in which the cleavage of bonds is accomplished by adding water
D. enzymes that catalyze the transfer of elements from one molecule to another
Stored polysaccharides in muscle and other tissues in animals are called
A. glucose.
B. fructose.
C. glycogen.
D. cellulose.
Fats that are stored in muscle and adipose tissue that play an important role as an energy substrate are
A. phospholipids.
B. cholesterol.
C. triglycerides.
D. lipoproteins.
The most important high-energy phosphate compound in the muscle cell is
The simplest and most rapid method of producing ATP during exercise is through
A. glycolysis.
B. ATP-CP system.
C. aerobic metabolism.
D. glycogenolysis.
Which of the following statements about glycolysis is correct?
A. glycolysis occurs in the mitochondrial matrix.
B. glycolysis ends with the production of pyruvic acid or lactic acid.
C. glycolysis can start with glucose of fatty acids.
D. glycolysis doesn't produce any ATP.
If muscle glycogen is the initial substrate, ____________ ATP can be produced via glycolysis.
A. 2.
B. 3.
C. 32.
D. 33.
The two most important hydrogen (electron) carriers in bioenergetic chemical reactions are
A. NAD and ATP.
B. FAD and ATP.
C. NAD and FAD.
D. NAD and LDH.
The primary function of the Krebs cycle is to
A. complete the oxidation of carbohydrates, fats, and proteins (i.e., form NADH and FADH).
B. produce ATP via substrate-level phosphorylation.
C. prime glycolysis for the production of ATP.
D. produce H2O and ATP.
Aerobic production of ATP occurs in the
A. mitochondria in a process called glycolysis.
B. mitochondria (i.e., electron transport chain) in a process called oxidative phosphorylation.
C. mitochondria in a process called beta oxidation.
D. cytoplasm.
.Each pair of electrons passed through the electron transport chain from NADH to oxygen releases enough energy to form
A. 1.5 ATP.
B. 2.5 ATP.
C. 5.0 ATP.
D. 10.0 ATP.
The total ATP production via aerobic breakdown of glucose is
A. 32 ATP.
B. 36 ATP.
C. 38 ATP.
D. 39 ATP
The calculated efficiency for aerobic respiration is approximately
A. 0%.
B. 34%.
C. 100%.
D. 66%.
The breakdown of creatine phosphate is regulated by
A. the amount of lactate dehydrogenase in the muscle.
B. the amount of NAD in the sarcoplasm of the muscle.
C. ADP concentration in the cytoplasm.
D. the pH of the interstitial fluid.
The most important rate limiting enzyme in glycolysis is
A. lactate dehydrogenase.
B. hexokinase.
C. phosphofructokinase.
D. pyruvate kinase.
The rate limiting enzyme in the Krebs cycle is
A. isocitrate dehydrogenase.
B. hexokinase.
C. succinate dehydrogenase.
D. cytochrome oxidase.
In general, the higher the intensity of the activity, the greater the contribution of
A. aerobic energy production.
B. anaerobic energy production.
C. the Krebs cycle to the production of ATP.
D. the electron transport chain to the production of ATP.
A rate-limiting enzyme in the aerobic synthesis of ATP in the mitochondria is
A. phosphofructokinase.
B. isocitrate dehydrogenase.
C. myosin ATPase.
D. ATP synthase.
The conversion of pyruvate to lactate requires
A. the enzyme LDH.
B. NADH + H+.
C. both of these.
D. neither of these.
The process of beta-oxidation involves
A. breaking down stored triglycerides to FFA.
B. the addition of oxygen to a fatty acid.
C. the breakdown of a fatty acid to acetyl-CoA.
D. none of these.
The enzyme-substrate complex is
A. best described by the lock and key model.
B. not influenced by pH.
C. a terminal point for both the enzyme and substrate (neither can be reused).
D. more likely to occur in a 20 degrees C environment than a 40 degrees C one.
The caloric (kcal) yield of one gram of protein is
A. 4 kcal/g.
B. 7 kcal/g.
C. 9 kcal/g.
D. the same as that of one gram of fat.
The enzyme responsible for catalyzing the immediate energy system is
A. adenylate cyclase.
B. myosin ATPase.
C. creatine kinase.
D. lactate dehydrogenase
The accumulation of _________ would slow glycolysis by inhibiting its rate limiting enzyme.
C. Pi
D. none of these
The actual ATP yield from aerobic metabolism of one molecule of glucose is different from the theoretical yield because
A. the net production of ATP is higher than previously thought.
B. it accounts for the fact that an additional H+ is required to move ATP into the cytoplasm.
C. it eliminates the ATP derived from NADH and FADH2.
D. of all of these.
The shorter the activity, the ____________ the contribution of anaerobic energy sources.
A. greater
B. lesser
The primary purpose of the Krebs cycle is to
A. complete the oxidation of foodstuffs using NAD and FAD as hydrogen (electron) carriers.
B. catalyze the phosphorylation of ADP from creatine phosphate.
C. oxidize foodstuffs and transfer those electrons to pyruvic acid.
D. consume lactate.
Which of the following is true concerning the electron transport chain?
A. The associated oxidation and reduction reactions provide the energy needed to pump H+ ions into the mitochondrial matrix
B. The flow of H+ ions from the inter-membrane space back into the mitochondrial matrix powers the (aerobic) production of ADP
C. The electrons passed down the chain will eventually be used to help form water
D. The end result of the electron transport chain is the formation of oxygen
Body temperature increases slightly during exercise. This would have the effect of
A. increasing enzyme activity.
B. decreasing enzyme activity.
C. denaturing enzymes.
D. none of these.
In order to be oxidized for the eventual formation of ATP, amino acids must first be broken down into proteins.
Once pyruvic acid has been converted to lactic acid, it cannot be turned back into pyruvic acid.
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
A. glycolysis.
B. the ATP-CP system.
C. the Krebs cycle.
D. the electron transport chain.
The term oxygen deficit refers to the
A. lag in oxygen consumption at the beginning of exercise.
B. excess oxygen consumption during recovery from exercise.
C. amount of oxygen required to maintain a steady state during constant-load exercise.
D. amount of oxygen utilized by the ATP-PC system in the first few minutes of exercise.
Energy to run a maximal 400-meter race (i.e., 50 to 60 seconds) comes from
A. aerobic metabolism exclusively.
B. mostly aerobic metabolism with some anaerobic metabolism.
C. a combination of aerobic/anaerobic metabolism, with most of the ATP coming from anaerobic sources.
D. the ATP-CP system exclusively.
Energy to run a 40-yard dash comes
A. almost exclusively from the ATP-CP system.
B. exclusively from glycolysis.
C. almost exclusively from aerobic metabolism.
D. from a combination of aerobic/anaerobic metabolism, with most of the ATP being produced aerobically.
The energy to perform long-term exercise (i.e., >20 minutes) comes primarily from
A. aerobic metabolism.
B. a combination of aerobic/anaerobic metabolism, with anaerobic metabolism producing the bulk of the ATP.
C. anaerobic metabolism.
D. anaerobic metabolism, with the ATP-PC system producing the bulk of the ATP.
The lactate threshold is defined as the work rate or oxygen uptake at which there is a systematic
A. rise in blood levels of lactic acid.
B. rise in aerobic metabolism.
C. decrease in blood lactic acid concentration.
D. rise in blood levels of lactate dehydrogenase.
Which of the following factors may explain the rise in blood lactic acid at the lactate threshold?
A. an increased rate of lactate production
B. an increased rate of removal of lactic acid from the blood
C. both a and b
D. neither a nor b
A respiratory quotient (RQ) of 0.95 during steady-state exercise is suggestive of a(n)
A. high rate of carbohydrate metabolism.
B. high rate of fat metabolism.
C. equal rate of fat/carbohydrate metabolism.
D. high rate of protein metabolism.
When calculating the RQ, protein is often ignored. Why?
A. because protein generally plays a small role as a substrate
B. because it is impossible to calculate the RQ for protein
C. because protein cannot be used as a substrate during exercise
D. because the RQ for protein is 0
Most of the carbohydrate (e.g., for a rested, well-fed athlete) used as a substrate during high-intensity exercise comes from
A. muscle glycogen stores.
B. blood glucose.
C. liver glycogen stores.
D. glycogen stored in fat cells.
The process of breaking down triglycerides into free fatty acids and glycerol is called
A. beta oxidation.
B. glycogenolysis.
C. lipolysis.
D. lipogenesis.
Depletion of carbohydrate stores during exercise influences fat metabolism by
A. increasing the amount of muscle lactic acid production.
B. reducing the level of Krebs cycle intermediates.
C. increasing the rate of fat metabolism.
D. reducing the rate of protein metabolism
During the "rapid" portion of the oxygen debt (or EPOC), the excess VO2 is due to
A. high body temperature.
B. gluconeogenesis.
C. restoration of muscle CP and blood and muscle oxygen stores.
D. elevated blood levels of epinephrine and norepinephrine.
The oxygen debt is generally higher following heavy exercise when compared with light exercise because heavy exercise
A. produces more lactic acid.
B. 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.
C. results in a greater level of liver glycogen depletion.
D. is of shorter duration than light exercise.
Which of the following is true about VO2 during exercise?
A. VO2 increases linearly with work rate.
B. VO2 is an indicator of glycolytic ATP production.
C. VO2 drops sharply just prior to fatigue.
D. None of the above are true.
Removal of lactic acid following a bout of intense exercise is
A. more rapid if the subject rests, compared to performing light exercise.
B. more rapid if the subject performs heavy exercise (>70% VO2 max), compared to rest.
C. more rapid if the subject performs light exercise (~30% VO2 max), compared to rest.
D. the same whether the subject rests or performs light exercise (~30% VO2 max).
The slow rise in oxygen uptake over time during high-intensity, prolonged exercise is due to
A. high blood levels of lactic acid.
B. rising body temperature.
C. rising blood levels of insulin.
D. the increased amount of work necessary to maintain exercise.
Trained individuals have a lower oxygen deficit; this may be due to
A. having a lower VO2 max.
B. having a greater reliance on anaerobic pathways.
C. the involvement of the ATP-CP energy system.
D. having a better developed aerobic bioenergetic capacity.
. The primary fuel source during light-intensity (25% VO2 max) exercise is
A. muscle glycogen.
B. blood glucose.
C. muscle triglycerides.
D. plasma FFA.
The drift upward of VO2 during constant-load exercise in a hot environment is due to
A. rising blood levels of lactate.
B. decreasing blood levels of hormones.
C. increasing body temperature.
D. decreasing body temperature.
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
A. substrate shift phenomenon.
B. RQ effect.
C. crossover concept.
D. glycolytic surge.
The carbohydrate fuel source that becomes most important after 3-4 hours of moderate-intensity (~70% VO2 max) exercise is
A. muscle glycogen.
B. blood glucose.
C. muscle triglycerides.
D. plasma FFA.
Which of the following is true concerning the Cori Cycle?
A. It is one means of decreasing (metabolizing) accumulated lactate.
B. It may increase liver glycogen content.
C. It is supplied by glucose that has been removed from the blood.
D. It is a means by which glucose is synthesized from amino acids removed from the blood.
The primary fuel source during high-intensity (85% VO2 max) exercise is
A. muscle glycogen.
B. blood glucose.
C. muscle triglycerides.
D. plasma FFA.
The RQ for fat is
A. 0.70.
B. 0.82.
C. 0.85.
D. 1.00.
Which of the following conditions would result in a higher EPOC?
A. higher intensity of exercise
B. lower intensity of exercise
C. lower body temperature
D. lower blood lactate
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.
D. neither a nor b.
Which of the following is true concerning VO2 max?
A. It occurs at a lower intensity of exercise than the lactate threshold.
B. It is the maximal volume of oxygen that can be breathed into the lungs in one minute.
C. It is a valid measure of cardiovascular fitness.
D. It is the highest VO2 achieved during prolonged steady-state exercise.
During moderate-intensity (65% VO2 max) exercise, the percent of ATP derived from carbohydrates is ___________ the percent ATP from fats.
A. less than
B. equal to
C. greater than
The exercise intensity that promotes the greatest total grams of fat metabolized is
A. 20% of VO2 max.
B. 50% of VO2 max.
C. 80% of VO2 max.
D. 100% of VO2 max.
After the first few minutes of constant-load, submaximal exercise, VO2 reaches steady state, indicating that
A. the ATP demand is being met aerobically.
B. levels of lactic acid in the blood are very high.
C. the exercise can be continued indefinitely without fatigue.
D. the oxygen uptake is not sufficient to meet the ATP demand.
The maximal rate of fat oxidation, FATmax, typically occurs just before
A. VO2 max.
B. the LT.
C. oxygen deficit.
True / False Questions
35. 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.
The respiratory exchange ratio equals the respiratory quotient during short-term maximal exercise.
Fat contains more energy per gram than carbohydrates; therefore, ATP can be produced more rapidly from fats than from carbohydrates.
Trained individuals usually produce less lactate than untrained individuals when making the transition from rest to steady-state exercise.
Lactic acid accumulation contributes to muscle fatigue during exercise and causes the muscle soreness that may occur 24-48 hours after exercising.
The exercise intensity at which blood levels reach four millimoles per liter is termed the onset of blood lactate accumulation (OBLA).
While hormones circulate to all tissues, some affect only a few tissues. This is due to the
A. plasma concentration of the hormone.
B. training state of the subject.
C. type of receptor at the tissue.
D. concentration of the hormone.
The concentration of a hormone can be increased by A. decreasing the rate at which it is metabolized.
B. increasing the number of receptors.
C. increasing the rate at which it is excreted.
D. increasing the plasma volume.
When adenylate cyclase is activated by a hormone, the concentration of cyclic AMP increases in the cell even though the hormone does not enter the cell. This is an example of the __________________ mechanism of hormone action.
A. altering membrane transport
B. altering activity of DNA
C. second messenger
D. all of above
Steroid hormones exert their effect by
A. activating adenylate cyclase.
B. altering the activity of DNA.
C. blocking the effect of cyclic AMP.
D. causing an inflammation response.
Growth hormone
A. is released from the posterior pituitary.
B. spares plasma glucose during exercise.
C. is only elevated in children and adolescents.
D. All of the above are true.
If the thyroid gland does not produce a sufficient amount of T3 or T4, the resting metabolic rate will
A. increase.
B. decrease.
C. remain the same.
Which of the following hormones is secreted by the thyroid gland and plays a role in the regulation of plasma calcium levels?
A. thyroxine
B. triiodothyronine
C. calcitonin
D. parathyroid hormone
Which of the following is a hormone that is secreted by the adrenal medulla?
A. epinephrine
B. aldosterone
C. cortisol
D. angiotensin II
Which of the following may be related to changes in mood and pain perception during endurance exercise?
A. catecholamines
B. glucocorticoids
C. somatomedins
D. endorphins
The decrease in plasma volume and the increase in the osmolality of the plasma during exercise results in _________________ in antidiuretic hormone.
A. an increase
B. a decrease
C. no change
Given the importance of maintaining the plasma glucose concentration during exercise, insulin secretion would be expected to ______________ during exercise.
A. increase
B. decrease
C. remain the same
A hormone that is released from the pancreas at a higher rate during exercise to mobilize liver glucose and adipose tissue fatty acids is
A. glucagon.
B. somatostatin.
C. insulin.
D. none of the above.
The term describing the cessation of the menstrual cycle resulting from lower estrogen levels in some female athletes is
A. dysmenorrhea.
B. eumenorrhea.
C. amenorrhea.
D. menarche.
Muscle glycogen breakdown is stimulated by the catecholamines. It is also stimulated by
A. elevated H+ concentration.
B. increased intracellular Ca++.
C. both a and b.
D. neither a nor b—it is stimulated only by the catecholamines.
Which of the following hormones is believed to exert a "permissive" effect on the mobilization of glucose from liver and FFA from adipose tissue?
A. epinephrine
B. T3 and T4
C. insulin
D. glucagon
During exercise of about 40% VO2 max, the concentration of plasma cortisol
A. is lower than at rest.
B. is higher than at rest.
C. remains the same as at rest.
The primary effect of the elevated plasma concentration of growth hormone during intense exercise is to
A. increase the synthesis of contractile protein in muscle.
B. promote long bone growth.
C. favor the mobilization of FFA and reduces tissue use of blood glucose.
D. none of the above.
As a result of training, the sympathetic nervous system's response to a fixed submaximal work rate
A. is increased.
B. is decreased.
C. remains the same.
The changes in the plasma concentration of most of the hormones during maximal exercise would stimulate fatty acid mobilization from adipose tissue. The plasma-free fatty acid concentration, however, actually decreases. Why does this occur?
A. Fatty acid supply is depleted.
B. Hormones are ineffective in maximal work.
C. Lactic acid interferes with fatty acid mobilization.
D. High insulin levels secreted during maximal exercise interfere with fatty acid mobilization.
During exercise, blood glucose concentration is maintained by all of the following except
A. elevated mobilization of FFA from adipose tissue.
B. increased rate of gluconeogenesis.
C. blocking entry of glucose into cells.
D. elevated concentration of insulin.
. Insulin secretion would be highest
A. during prolonged exercise.
B. as exercise intensity increases.
C. after a meal.
D. It would be equally high after all of the above.
The mobilization of free fatty acids from adipose tissue and glucose from liver glycogen would be stimulated by
A. an increase in insulin and an increase in glucagon.
B. a decrease in insulin and an increase in glucagon.
C. an increase in insulin and a decrease in glucagon.
D. a decrease in insulin and a decrease in glucagon.
During exercise, epinephrine and norepinephrine stimulate liver glycogenolysis indirectly by
A. increasing glucagon secretion from the pancreas.
B. increasing insulin secretion from the pancreas.
C. increasing the uptake of FFA by muscle.
D. lowering plasma cortisol concentration.
Which of the following hormones is part of the General Adaptive Syndrome and is called the "stress" hormone?
A. epinephrine
B. renin
C. cortisol
D. insulin
Which of the following hormones is secreted from adipose tissue?
A. leptin
B. adiponectin
C. both a and b
D. neither a nor b
When a drug is given to block the adrenergic receptors during exercise, muscle glycogen utilization is reduced.
Chronic exposure to high levels of a hormone results in "up regulation" of receptors.
Blood epinephrine levels increase as exercise intensity increases, but decrease as exercise duration increases.
Glucagon secretion increases during exercise, which decreases liver glycogen stores in order to maintain blood glucose concentration.
Growth hormone secretion increases during exercise and decreases during sleep.
Even though the concentration of insulin decreases during exercise, the muscle can still take up large quantities of plasma glucose. This is due, in part, to the recruitment of more glucose transporters.