Maximal oxygen uptake primarily reflects the capacity of which system to deliver and use oxygen during whole-body exercise?
A) Integumentary system
B) Digestive system
C) Cardiovascular and respiratory systems
D) Urinary system
Correct answer: C
Explanation: Maximal oxygen uptake depends on the ability of the cardiovascular and respiratory systems to transport oxygen to working muscle and on the muscle’s ability to use it.

 

During the first seconds of an all-out sprint lasting ten seconds, the predominant energy source is:
A) Oxidation of fatty acids
B) Oxidation of glucose
C) Phosphocreatine breakdown and stored adenosine triphosphate
D) Oxidation of amino acids
Correct answer: C
Explanation: Very short, maximal efforts rely on immediate energy from stored adenosine triphosphate and rapid phosphocreatine breakdown.

 

Which statement best describes the lactate threshold during incremental exercise?
A) The point where fat use stops entirely
B) The intensity where blood lactate begins to rise faster than it can be removed
C) The highest intensity at which blood lactate is zero
D) The point where ventilation decreases
Correct answer: B
Explanation: Lactate threshold is identified when production exceeds clearance, causing a systematic rise.

 

Which fiber type generally has the highest oxidative capacity?
A) Fast-twitch glycolytic
B) Slow-twitch
C) Fast-twitch intermediate
D) Fast-twitch fatigable
Correct answer: B
Explanation: Slow-twitch fibers have more mitochondria, capillaries, and myoglobin, supporting sustained oxidative metabolism.

 

Excess post-exercise oxygen consumption is best explained by:
A) Oxygen stored in the lungs refilling
B) Ongoing processes to restore homeostasis including phosphocreatine resynthesis and temperature recovery
C) Carbon dioxide storage in bone
D) Continued digestion after exercise
Correct answer: B
Explanation: Elevated oxygen use after exercise reflects recovery processes such as phosphocreatine resynthesis, thermoregulation, and hormonal adjustments.

 

True or false: Stroke volume typically increases with exercise intensity and then plateaus at moderate to high intensities in many individuals.
Correct answer: True
Explanation: Stroke volume rises from rest and often plateaus before maximal intensity, while heart rate continues to rise.

 

Fill in the blank: The difference between the oxygen content of arterial blood and venous blood is called the ____________________________.
Correct answer: arteriovenous oxygen difference
Explanation: It reflects oxygen extraction by tissues.

 

Short answer: Define cardiovascular drift and state one main contributing factor.
Correct answer: Cardiovascular drift is a gradual increase in heart rate and a decrease in stroke volume during prolonged steady-state exercise, often in heat. A main contributing factor is fluid loss and rising body temperature.
Explanation: Reduced plasma volume and thermoregulatory demands shift cardiovascular responses over time.

 

Which variable is most directly used to calculate cardiac output?
A) Blood pressure and total peripheral resistance
B) Stroke volume and heart rate
C) End-diastolic volume and end-systolic volume only
D) Hemoglobin concentration and saturation
Correct answer: B
Explanation: Cardiac output equals stroke volume times heart rate.

 

During submaximal exercise, an increase in end-diastolic volume because of venous return most directly enhances stroke volume through which mechanism?
A) Bohr effect
B) Frank-Starling mechanism
C) Haldane effect
D) Reduced afterload
Correct answer: B
Explanation: Greater filling stretches cardiac fibers and increases force of contraction up to an optimal length.

 

True or false: Hyperventilation at rest will increase carbon dioxide in blood.
Correct answer: False
Explanation: Hyperventilation decreases carbon dioxide due to excess removal.

 

Fill in the blank: The respiratory exchange ratio near 0.70 suggests predominant ____________________________ oxidation.
Correct answer: fat
Explanation: Lower values indicate a higher proportion of fat use; values near 1.00 indicate carbohydrate use.

 

Short answer: Why does maximal oxygen uptake usually increase after endurance training? Provide two physiological adaptations.
Correct answer: Endurance training increases maximal oxygen uptake by increasing stroke volume via expanded plasma volume and cardiac remodeling, and by increasing muscle oxidative capacity through more mitochondria and capillaries.
Explanation: Central delivery and peripheral extraction both improve.

 

During high-intensity exercise lasting two minutes, the largest contribution to adenosine triphosphate resynthesis typically comes from:
A) Immediate phosphocreatine system only
B) Anaerobic glycolysis with growing oxidative support
C) Fat oxidation
D) Protein oxidation
Correct answer: B
Explanation: Efforts around one to three minutes rely heavily on glycolysis while oxidative metabolism ramps up.

 

Which change is expected in the oxygen-hemoglobin dissociation curve during heavy exercise with increased temperature and hydrogen ions?
A) Leftward shift, increased affinity
B) No shift
C) Rightward shift, decreased affinity
D) Vertical shift with no change in affinity
Correct answer: C
Explanation: The Bohr effect shifts the curve right, facilitating oxygen unloading at the muscle.

 

True or false: Slow-twitch fibers generate less absolute force than fast-twitch fibers but resist fatigue better.
Correct answer: True
Explanation: Slow-twitch fibers have slower shortening velocity and greater endurance due to oxidative capacity.

 

Fill in the blank: The maximum amount of air that can be exhaled following a maximal inhalation is called the ____________________________.
Correct answer: vital capacity
Explanation: Vital capacity equals inspiratory reserve volume plus tidal volume plus expiratory reserve volume.

 

Short answer: Define oxygen deficit at exercise onset.
Correct answer: Oxygen deficit is the difference between the energy required at the onset of exercise and the oxygen actually consumed, before steady-state is reached.
Explanation: Immediate energy is supplied by stored adenosine triphosphate and phosphocreatine and by anaerobic glycolysis.

 

Which hormone increases blood glucose by promoting liver glucose release during exercise?
A) Insulin
B) Glucagon
C) Aldosterone
D) Antidiuretic hormone
Correct answer: B
Explanation: Glucagon stimulates glycogen breakdown and glucose release; insulin typically decreases during exercise.

 

What is the most important immediate stimulus for increased ventilation at the start of exercise?
A) Increased arterial oxygen
B) Central command and rapid neural feedback from muscles and joints
C) Slow endocrine signals
D) Decreased body temperature
Correct answer: B
Explanation: Feedforward signals and neural feedback rapidly increase ventilation before chemical changes fully develop.

 

True or false: During prolonged moderate exercise in the heat, plasma volume tends to increase.
Correct answer: False
Explanation: Sweating and fluid shifts reduce plasma volume unless fluids are replaced.

 

Fill in the blank: The highest running speed at which a person can sustain a steady state of oxygen consumption is often near the ____________________________.
Correct answer: maximal oxygen uptake running speed
Explanation: At speeds near maximal oxygen uptake, steady state is not always achievable, marking a performance boundary.

 

Short answer: Explain why trained individuals have lower blood lactate at a given submaximal workload than untrained individuals.
Correct answer: Trained individuals show greater oxidative capacity and lactate clearance, increased capillary density, and higher mitochondrial content, reducing reliance on glycolysis at the same workload.
Explanation: Enhanced transport and oxidation limit accumulation.

 

The primary cellular site of aerobic adenosine triphosphate production is the:
A) Nucleus
B) Cytosol only
C) Mitochondrion
D) Lysosome
Correct answer: C
Explanation: Oxidative phosphorylation and the citric acid cycle occur in mitochondria.

 

Which change most directly increases end-diastolic volume during dynamic exercise?
A) Lower venous return
B) Higher intrathoracic pressure during inhalation
C) Enhanced muscle pump and venoconstriction
D) Decreased heart rate
Correct answer: C
Explanation: Skeletal muscle contractions and sympathetic venous tone promote venous return.

 

True or false: The ventilatory threshold typically occurs at a lower intensity than the lactate threshold.
Correct answer: False
Explanation: They often occur near each other, but ventilatory threshold commonly tracks the lactate accumulation point; neither is consistently lower than the other across all individuals.

 

Fill in the blank: The capacity to buffer hydrogen ions produced during intense exercise is improved by increased ____________________________ content within muscle.
Correct answer: carnosine and other intracellular buffers
Explanation: Intracellular buffers help resist pH decline during high rates of glycolysis.

 

Short answer: Describe two cardiovascular adaptations to endurance training that lower submaximal heart rate.
Correct answer: Expanded plasma volume and greater stroke volume, plus increased parasympathetic tone and reduced sympathetic drive, lower heart rate at a given workload.
Explanation: Higher stroke volume meets the same cardiac output with fewer beats.

 

Which of the following best explains why arm exercise elicits higher heart rate than leg exercise at the same oxygen uptake?
A) Greater muscle mass in arms
B) Less sympathetic activation in arm exercise
C) Higher peripheral resistance and lower mechanical efficiency with arm exercise
D) Greater venous return during arm exercise
Correct answer: C
Explanation: Arm exercise is less efficient and produces greater pressor responses at a given oxygen uptake.

 

During prolonged exercise, which hormone primarily promotes water retention?
A) Thyroxine
B) Antidiuretic hormone
C) Insulin
D) Parathyroid hormone
Correct answer: B
Explanation: Antidiuretic hormone increases water reabsorption in the kidney.

 

True or false: The partial pressure of oxygen in arterial blood decreases markedly during low-to-moderate intensity exercise at sea level in healthy individuals.
Correct answer: False
Explanation: In healthy individuals at sea level, arterial oxygen content is well maintained during moderate exercise.

 

Fill in the blank: The volume of air exchanged per minute is called ____________________________ and equals tidal volume times breathing frequency.
Correct answer: minute ventilation
Explanation: It describes overall ventilation per minute.

 

Short answer: What is the effect of endurance training on the number of capillaries around each muscle fiber and why does that matter?
Correct answer: Training increases capillary density, improving oxygen delivery, substrate transport, and removal of heat and by-products, which enhances endurance performance.
Explanation: Short diffusion distances favor aerobic metabolism.

 

Which substrate contributes the greatest fraction of energy during very high-intensity exercise lasting thirty seconds?
A) Fatty acids
B) Blood glucose only
C) Phosphocreatine and muscle glycogen via glycolysis
D) Amino acids
Correct answer: C
Explanation: Immediate and glycolytic pathways dominate very short, very intense efforts.

 

Which variable most strongly limits maximal oxygen uptake in healthy, well-trained individuals?
A) Pulmonary diffusion capacity
B) Oxygen carrying capacity at rest
C) Maximal cardiac output
D) Skin blood flow
Correct answer: C
Explanation: In most healthy people, maximal oxygen uptake is limited primarily by central oxygen delivery, especially maximal cardiac output.

 

True or false: Resistance training never improves maximal oxygen uptake.
Correct answer: False
Explanation: Resistance training alone produces small changes, but circuit-like or high-volume resistance training can yield modest increases; combined training can increase maximal oxygen uptake more.

 

Fill in the blank: The increase in breathing at the beginning of exercise before chemical changes occur is due to ____________________________ and neural feedback.
Correct answer: central command
Explanation: Feedforward signals from motor areas anticipate metabolic needs.

 

Short answer: Define the term economy of movement and state one factor that influences it in running.
Correct answer: Economy of movement is the oxygen cost at a given submaximal speed. It is influenced by biomechanics such as stride mechanics and stiffness of the musculoskeletal system.
Explanation: Lower oxygen cost at a given speed reflects better economy.

 

Which training method most effectively increases mitochondrial enzyme activity in skeletal muscle?
A) Low-repetition, high-load resistance training only
B) Sprint training once per week
C) Regular endurance training with sustained or interval workloads
D) Flexibility training
Correct answer: C
Explanation: Repeated aerobic stress stimulates mitochondrial biogenesis.

 

During heavy exercise in heat, which circulatory trade-off can limit performance?
A) Reduced skin blood flow to favor muscle at all times
B) Competition between skin and muscle for blood flow
C) Elimination of muscle blood flow to protect the brain
D) Increased kidney blood flow to aid cooling
Correct answer: B
Explanation: Thermoregulation requires skin blood flow, which can reduce available flow to muscle.

 

True or false: The oxygen cost of breathing increases as exercise intensity rises, especially near maximal effort.
Correct answer: True
Explanation: Respiratory muscles work harder at higher ventilation rates, increasing their oxygen use.

 

Fill in the blank: The primary reason for a lower resting and submaximal heart rate in trained individuals is a higher ____________________________.
Correct answer: stroke volume
Explanation: Higher stroke volume allows the same cardiac output with fewer beats.

 

Short answer: Explain why blood lactate can be used to estimate training intensity domains.
Correct answer: Blood lactate reflects the balance of production and clearance. Systematic rise points mark transitions between moderate, heavy, and severe intensity domains.
Explanation: It aligns with metabolic and ventilatory responses.

 

Which intracellular signal is most directly linked to mitochondrial biogenesis after endurance exercise?
A) Increased cytosolic sodium
B) Increased protein kinase signaling including the coactivator commonly called PGC-1 alpha
C) Decreased calcium transients
D) Lower adenosine monophosphate to adenosine triphosphate ratio
Correct answer: B
Explanation: Exercise activates kinase pathways and the coactivator that promote mitochondrial gene expression.

 

In altitude exposure at rest and during submaximal exercise, which initial ventilatory change is typical?
A) Decrease in breathing frequency
B) Hyperventilation to compensate for reduced arterial oxygen pressure
C) No change
D) Complete cessation of breathing during sleep
Correct answer: B
Explanation: Reduced inspired oxygen pressure stimulates ventilation to maintain oxygenation.

 

True or false: Fast-twitch fibers have greater maximal shortening velocity than slow-twitch fibers.
Correct answer: True
Explanation: Fast myosin isoforms and calcium handling support faster contraction speeds.

 

Fill in the blank: The increase in muscle fiber size after resistance training is termed ____________________________.
Correct answer: hypertrophy
Explanation: Hypertrophy is growth of existing fibers; hyperplasia refers to an increase in fiber number.

 

Short answer: How does endurance training affect the respiratory exchange ratio at a given submaximal workload and why?
Correct answer: It tends to lower the respiratory exchange ratio at the same workload because trained muscle increases fat oxidation and spares glycogen.
Explanation: Adaptations shift substrate use.

 

Which change would most likely increase venous return during rhythmic leg exercise?
A) Prolonged Valsalva maneuver
B) Greater skeletal muscle pump activity
C) Standing still between intervals
D) Higher intrathoracic pressure during exhalation only
Correct answer: B
Explanation: Repeated muscle contractions compress veins and propel blood back to the heart.

 

During prolonged exercise, which substrate becomes increasingly important as muscle glycogen declines?
A) Amino acids only
B) Fatty acids and blood glucose
C) Adenosine triphosphate stores
D) Phosphocreatine only
Correct answer: B
Explanation: Blood glucose and fat oxidation support energy as glycogen depletes.

 

True or false: At a fixed absolute workload, trained individuals usually have lower ventilation than untrained individuals.
Correct answer: True
Explanation: Improved efficiency and reduced metabolic acidosis lower ventilatory drive.

 

Fill in the blank: The product of arteriovenous oxygen difference and cardiac output equals ____________________________.
Correct answer: oxygen consumption
Explanation: This is the Fick principle.

 

Short answer: Why does heart rate recovery after exercise occur faster in trained individuals?
Correct answer: Enhanced parasympathetic reactivation and lower sympathetic activity, along with efficient thermoregulation and lower metabolic disturbance, speed the decline in heart rate.
Explanation: Autonomic balance shifts quickly toward recovery.

 

Which factor most directly increases oxygen diffusion from blood to muscle during exercise?
A) Reduced capillary recruitment
B) Increased capillary surface area and shorter diffusion distance
C) Lower muscle temperature
D) Decreased mitochondrial density
Correct answer: B
Explanation: Greater capillary perfusion and surface area enhance diffusion.

 

Which statement about the phosphocreatine system is correct?
A) It provides energy slowly but for a long duration
B) It provides energy rapidly but depletes quickly
C) It requires oxygen to function
D) It relies on fatty acids
Correct answer: B
Explanation: Phosphocreatine quickly donates phosphate to adenosine diphosphate but stores are limited.

 

True or false: Blood flow to the kidneys and digestive organs tends to decrease during intense dynamic exercise.
Correct answer: True
Explanation: Sympathetic vasoconstriction redistributes blood toward muscle and skin.

 

Fill in the blank: The relationship between heart rate and oxygen consumption during incremental exercise is approximately ____________________________ over a wide range of intensities.
Correct answer: linear
Explanation: Heart rate rises roughly in proportion to oxygen consumption until near maximal efforts.

 

Short answer: Define rating of perceived exertion and describe one use in training.
Correct answer: Rating of perceived exertion is a self-reported measure of effort during activity. It can guide intensity when heart rate monitoring is impractical or when medications alter heart rate.
Explanation: It correlates with physiological strain.

 

Which pulmonary volume increases most from rest to heavy exercise?
A) Residual volume
B) Tidal volume and breathing frequency together
C) Total lung capacity
D) Functional residual capacity
Correct answer: B
Explanation: Both tidal volume and frequency increase to raise minute ventilation.

 

Which factor most strongly increases skin blood flow during exercise in heat?
A) Increased carbon dioxide
B) Reduced arterial oxygen
C) Thermoregulatory signals from the hypothalamus causing cutaneous vasodilation
D) Reduced plasma volume
Correct answer: C
Explanation: Temperature regulation drives vasodilation to move heat to the skin.

 

True or false: Muscle glycogen supercompensation strategies can increase glycogen storage and delay fatigue in endurance events.
Correct answer: True
Explanation: Proper depletion and carbohydrate intake protocols raise glycogen above normal.

 

Fill in the blank: The ratio of ventilation to oxygen consumption is called the ____________________________.
Correct answer: ventilatory equivalent for oxygen
Explanation: It reflects ventilatory efficiency.

 

Short answer: State two reasons why children have lower glycolytic capacity than adults during maximal exercise.
Correct answer: Children have lower activity of key glycolytic enzymes and rely more on oxidative metabolism; they also have smaller muscle mass and different hormonal responses.
Explanation: These factors limit lactate accumulation and anaerobic power.

 

Which neuromuscular change most directly increases maximal voluntary force after early weeks of resistance training?
A) Immediate large muscle hypertrophy
B) Improved motor unit recruitment and synchronization
C) Decreased neural drive
D) Fewer active fibers
Correct answer: B
Explanation: Early strength gains are largely neural before substantial hypertrophy.

 

During high-intensity interval training, which variable most strongly determines the contribution of anaerobic glycolysis?
A) Length of recovery intervals only
B) Work interval duration and intensity
C) Ambient temperature
D) Body mass alone
Correct answer: B
Explanation: Higher intensity and longer work intervals increase glycolytic contribution.

 

True or false: Blood hemoglobin concentration always increases during a single prolonged exercise session.
Correct answer: False
Explanation: Apparent increases often reflect hemoconcentration from fluid loss; true red cell mass does not rise acutely.

 

Fill in the blank: The tendency for blood pH to decrease during intense exercise is termed exercise-induced ____________________________.
Correct answer: metabolic acidosis
Explanation: Accumulated hydrogen ions from glycolysis and other sources lower pH.

 

Short answer: Why does ventilation continue to be elevated briefly after very intense exercise?
Correct answer: Ongoing carbon dioxide removal, temperature regulation, and restoration of acid–base balance keep ventilatory drive high during recovery.
Explanation: Recovery processes sustain higher breathing.

 

Which combination best describes typical chronic adaptations to high-volume endurance training?
A) Decreased capillary density and decreased mitochondrial content
B) Increased capillary density and increased mitochondrial content
C) Decreased stroke volume and increased resting heart rate
D) Increased blood pressure at rest
Correct answer: B
Explanation: Endurance training enhances oxygen delivery and use.

 

Which factor most directly increases maximal stroke volume after months of endurance training?
A) Reduced heart size
B) Increased left ventricular volume and compliance
C) Increased peripheral resistance
D) Loss of plasma volume
Correct answer: B
Explanation: Structural and functional cardiac changes allow greater filling and ejection.

 

True or false: During submaximal exercise at the same relative intensity, women and men display identical absolute oxygen consumption values.
Correct answer: False
Explanation: Relative intensity can be the same, but absolute oxygen consumption differs with body size and muscle mass.

Fill in the blank: The increase in the number of mitochondria in trained muscle is called mitochondrial ____________________________.
Correct answer: biogenesis
Explanation: Biogenesis reflects synthesis of new mitochondrial components.

 

Short answer: Explain why ingesting fluid and electrolytes can help maintain performance during prolonged exercise in the heat.
Correct answer: Fluids replace sweat losses to maintain plasma volume, supporting stroke volume and skin blood flow, while electrolytes aid fluid retention and neuromuscular function.
Explanation: Cardiovascular and thermoregulatory stability preserves output.

 

Which primary factor determines whether steady-state oxygen consumption is achievable during constant-load exercise?
A) Ambient light
B) Whether the work rate is below the heavy-to-severe intensity boundary
C) Footwear choice
D) Body mass index category
Correct answer: B
Explanation: Above a critical boundary, oxygen consumption drifts upward and steady state is not maintained.

 

Which mechanism explains the rapid initial decline in heart rate during the first minute after exercise?
A) Slow metabolic clearance only
B) Parasympathetic reactivation
C) Dehydration
D) Increased catecholamines
Correct answer: B
Explanation: Vagal tone returns quickly, lowering heart rate.

 

True or false: Muscle temperature decreases during short, intense exercise.
Correct answer: False
Explanation: Muscle temperature rises with metabolic heat production.

 

Fill in the blank: The transport of lactate between tissues to be oxidized or converted to glucose is called the ____________________________.
Correct answer: lactate shuttle
Explanation: Lactate is a fuel and signaling molecule transported and used by various tissues.

 

Short answer: Why can high-intensity interval training improve endurance performance despite short total training time?
Correct answer: Repeated severe-intensity bouts strongly stimulate central and peripheral adaptations, including mitochondrial biogenesis and improved oxygen delivery, producing gains similar to longer moderate training.
Explanation: The strong stimulus compensates for lower duration.

 

During prolonged cycling at a constant power in the heat, an increase in heart rate over time with maintained oxygen consumption indicates:
A) Cardiovascular drift
B) Central command failure
C) Onset of disease
D) Hyperventilation syndrome
Correct answer: A
Explanation: Heart rate rises to maintain cardiac output as stroke volume decreases.

 

Which factor reduces the oxygen cost of running at a given speed?
A) Excessive vertical oscillation
B) Improved elastic energy storage and return
C) Overstriding
D) Unstable footwear
Correct answer: B
Explanation: Effective use of elastic structures lowers metabolic cost.

 

True or false: The ventilatory equivalent for oxygen typically rises at intensities above the lactate threshold.
Correct answer: True
Explanation: Increased ventilatory drive relative to oxygen consumption reflects buffering of hydrogen ions and carbon dioxide output.

 

Fill in the blank: The pressure-volume relationship of the heart that influences afterload is most closely related to ____________________________.
Correct answer: arterial pressure
Explanation: Afterload reflects the resistance the ventricle must overcome, closely tied to arterial pressure.

 

Short answer: State one reason why older adults may have lower maximal oxygen uptake even when physically active.
Correct answer: Maximal heart rate and maximal stroke volume decline with age, reducing maximal cardiac output; peripheral factors like reduced muscle mass also contribute.
Explanation: Central and peripheral changes with aging limit maximal oxygen uptake.

 

Which training approach is most effective to increase one-repetition maximum strength?
A) Low-load, very high repetition training exclusively
B) High-load, low repetition training with progressive overload
C) Stretching only
D) Endurance cycling only
Correct answer: B
Explanation: Heavier loads stimulate neural adaptations and hypertrophy.

 

Which of the following most directly increases oxygen delivery to active muscle during exercise?
A) Reduced heart rate
B) Increased cardiac output and local vasodilation
C) Generalized vasoconstriction of muscle
D) Decreased hemoglobin concentration
Correct answer: B
Explanation: Higher flow and local dilation direct more oxygenated blood to active tissue.

 

True or false: The partial pressure of oxygen in the alveoli always equals the partial pressure of oxygen in arterial blood during heavy exercise.
Correct answer: False
Explanation: Small alveolar-arterial gradients can develop at high ventilation and flow.

 

Fill in the blank: The buildup of heat that impairs performance during long exercise in warm conditions is called ____________________________.
Correct answer: hyperthermia
Explanation: Excess body heat disrupts function.

 

Short answer: Explain why a warm-up can improve performance in short, intense efforts.
Correct answer: Warm-up raises muscle temperature, speeds enzyme kinetics, enhances nerve conduction, and improves oxygen delivery kinetics, reducing oxygen deficit.
Explanation: These changes improve power output and coordination.

 

Which statement best describes the effect of dehydration of two percent of body mass on endurance performance in heat?
A) No effect
B) Likely small to moderate impairment due to reduced plasma volume and thermoregulation
C) Large improvement from reduced mass
D) Only psychological effects
Correct answer: B
Explanation: Reduced plasma volume decreases stroke volume and skin blood flow, increasing strain.

 

Which of the following best explains why trained endurance athletes have higher lactate threshold expressed as a percentage of maximal oxygen uptake?
A) Lower mitochondrial density
B) Greater buffering, capillarization, and mitochondrial content
C) Lower stroke volume
D) Reduced fat use
Correct answer: B
Explanation: Multiple adaptations delay lactate accumulation to higher intensities.

 

True or false: Muscle fiber type distribution is entirely determined by training with no genetic influence.
Correct answer: False
Explanation: Training can modify properties, but genetic factors influence distribution.

 

Fill in the blank: The highest running speed that can be sustained for several minutes without continual rise in oxygen consumption is sometimes approximated by the ____________________________.
Correct answer: critical speed
Explanation: Critical speed marks the boundary between heavy and severe intensity domains.

 

Short answer: Describe one acute and one chronic effect of resistance training on blood pressure.
Correct answer: Acutely, heavy lifts raise blood pressure due to pressor responses. Chronically, regular resistance training can reduce resting blood pressure modestly in some individuals.
Explanation: Different time scales show different effects.

 

Which blood variable increases to enhance oxygen transport during acclimatization to high altitude?
A) Plasma water only
B) Hemoglobin concentration through increased red cell production
C) Platelet count
D) Calcium concentration
Correct answer: B
Explanation: Kidney-derived signals increase red blood cell production, raising oxygen carrying capacity.

 

Which best explains the reduction in reliance on carbohydrate at a given absolute workload after endurance training?
A) Lower fat transport
B) Increased fat transport and oxidation with glycogen sparing
C) Decreased mitochondrial enzymes
D) Reduced capillaries
Correct answer: B
Explanation: Adaptations shift substrate use toward fat at the same workload.

 

True or false: Prolonged sitting before a workout has no effect on exercise responses.
Correct answer: False
Explanation: Reduced venous return and stiffness can transiently alter responses; a warm-up helps.

 

Fill in the blank: The term describing reduced performance following excessive training without adequate recovery, but typically reversible with rest, is ____________________________.
Correct answer: functional overreaching
Explanation: It is a short-term imbalance that can be planned or unplanned.

 

Short answer: Why does inspiratory muscle training sometimes improve endurance performance?
Correct answer: It can reduce the oxygen cost of breathing and delay respiratory muscle fatigue, thereby preserving blood flow for locomotor muscles.
Explanation: Lower respiratory muscle demand reduces overall strain.

 

Which environmental condition most increases evaporative heat loss during exercise?
A) High humidity
B) Low humidity with air movement
C) Still air at high humidity
D) No air movement at any humidity
Correct answer: B
Explanation: Dry air and airflow promote sweat evaporation.

 

Which of the following primarily explains the steeper heart rate increase when the same absolute workload is performed with smaller active muscle mass?
A) Lower sympathetic activation
B) Greater peripheral resistance and pressor response
C) Higher venous return
D) Lower metabolic cost
Correct answer: B
Explanation: Smaller muscle mass increases peripheral resistance and cardiovascular strain at the same workload.

 

True or false: During exhaustive exercise, central nervous system factors can contribute to fatigue in addition to peripheral mechanisms.
Correct answer: True
Explanation: Motivation, neurotransmitters, and brain temperature can influence effort and motor drive.

 

Fill in the blank: The process by which glucose is produced from non-carbohydrate precursors during prolonged exercise is called ____________________________.
Correct answer: gluconeogenesis
Explanation: The liver uses substrates such as lactate and amino acids to produce glucose.

 

Short answer: What is the main reason a cold environment can impair endurance performance without proper clothing?
Correct answer: Increased heat loss elevates metabolic cost to maintain temperature, and vasoconstriction can limit muscle blood flow and joint function.
Explanation: Thermoregulation competes with performance.

 

Which combination of training variables best supports increases in maximal oxygen uptake for most individuals?
A) Very low frequency and very low intensity
B) Moderate to high frequency with moderate to vigorous intensity and progressive overload
C) Flexibility only
D) Random sessions without structure
Correct answer: B
Explanation: Regular, challenging aerobic work with progression produces robust gains.

 

Which change during endurance training most closely explains improved submaximal ventilation efficiency?
A) Reduced tidal volume
B) Increased tidal volume with lower breathing frequency
C) Constant small breaths at high frequency
D) Lower oxygen diffusion capacity
Correct answer: B
Explanation: Deeper, slower breathing reduces dead space ventilation relative to alveolar ventilation.

 

True or false: Muscle oxidative capacity can improve within weeks of training.
Correct answer: True
Explanation: Mitochondrial enzymes and capillaries adapt within weeks.

 

Fill in the blank: The increase in carbon dioxide output relative to oxygen consumption above the second ventilatory breakpoint reflects greater ____________________________ from buffering.
Correct answer: carbon dioxide production
Explanation: Buffering of hydrogen ions produces additional carbon dioxide, stimulating ventilation.

 

Short answer: Give one reason why interval training can benefit individuals with limited time while still improving health.
Correct answer: Alternating intense and easy efforts produces strong cardiometabolic stimuli in short sessions, improving insulin sensitivity, blood pressure, and cardiorespiratory fitness.
Explanation: The dose of intensity drives adaptation.

 

Which variable is most practical for day-to-day monitoring of internal training load across different exercise modes?
A) Shoe color
B) Session rating of perceived exertion times duration
C) Maximum heart rate measured monthly
D) Body mass index
Correct answer: B
Explanation: The product of session rating and duration integrates intensity and time across modes.

 

Which occurs during an effective taper before an endurance event?
A) Increased training volume and intensity
B) Reduced training volume with maintained intensity
C) Elimination of all intensity and volume
D) Only strength training
Correct answer: B
Explanation: Lower volume with preserved intensity maintains adaptations while reducing fatigue.

 

True or false: The force-velocity relationship shows that maximal force decreases as shortening velocity increases in concentric contractions.
Correct answer: True
Explanation: Cross-bridge cycling limits force at higher velocities.

 

Fill in the blank: The circulatory adaptation that increases venous return during rhythmic muscle contractions is commonly called the ____________________________.
Correct answer: muscle pump
Explanation: Alternating compression and relaxation propel blood toward the heart.

 

Short answer: Why is carbohydrate intake during endurance events beneficial even when starting with high glycogen?
Correct answer: It maintains blood glucose, spares glycogen, and may support central nervous system function, delaying fatigue.
Explanation: Exogenous carbohydrate supports sustained power output.

 

Which of the following is the best indicator that a constant-load exercise bout is above the heavy-to-severe boundary?
A) Oxygen consumption reaches steady state in three minutes
B) Oxygen consumption drifts upward without plateau and exhaustion occurs within tens of minutes
C) Heart rate decreases steadily
D) Ventilation falls as intensity rises
Correct answer: B
Explanation: Severe intensity prevents steady state and leads to limited tolerance time.

 

Which neuromuscular factor explains greater rate of force development after explosive training?
A) Reduced motor unit firing rate
B) Increased motor unit firing rate and earlier recruitment of fast units
C) Fewer active motor units
D) Smaller neural drive
Correct answer: B
Explanation: Rapid activation and recruitment enhance early force.

 

True or false: The total oxygen debt concept is identical to excess post-exercise oxygen consumption as used today.
Correct answer: False
Explanation: Modern understanding attributes recovery oxygen use to multiple processes rather than a single debt repayment.

 

Fill in the blank: The minimal running speed that elicits maximal oxygen uptake is called the ____________________________.
Correct answer: speed at maximal oxygen uptake
Explanation: It is a useful performance metric and training reference.

 

Short answer: Describe one peripheral and one central factor that limit maximal endurance performance.
Correct answer: Peripheral: limited mitochondrial oxidative capacity and substrate availability. Central: maximal cardiac output and oxygen delivery.
Explanation: Both delivery and utilization constrain performance.

 

Which training adaptation most directly improves heat tolerance?
A) Reduced plasma volume
B) Increased plasma volume and earlier sweating
C) Reduced sweat rate
D) Lower skin blood flow
Correct answer: B
Explanation: More plasma supports skin blood flow and sweating, promoting cooling.

 

Which description best matches the slow component of oxygen consumption during heavy constant-load exercise?
A) Immediate rise to steady state
B) Continued gradual increase in oxygen consumption over time
C) Sudden drop in oxygen consumption
D) No change
Correct answer: B
Explanation: Oxygen consumption drifts upward due to additional motor unit recruitment and metabolic factors.

 

True or false: Performing resistance training on alternate days is sufficient stimulus for most beginners to gain strength.
Correct answer: True
Explanation: Two to three sessions per week with progressive overload usually elicit gains.

 

Fill in the blank: The increase in heart rate before exercise due to anticipation is called ____________________________.
Correct answer: anticipatory response
Explanation: Central command prepares the body for effort.

 

Short answer: Why does wearing very tight, non-breathable clothing impair thermoregulation during exercise?
Correct answer: It traps heat and sweat, reduces evaporation, and limits convective heat loss, increasing heat storage.
Explanation: Evaporation is the main avenue of heat loss during exercise in warm conditions.