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ACSM EP-C study materials
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ACSM EP-C practice questions

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Question 1Exercise Physiology and Anatomy

During a concentric muscle action, which structure of the sarcomere maintains a constant length?

  1. Distance between the two Z lines
  2. A band Correct answer.
  3. H zone
  4. I band

Explanation

The A band spans the full length of the thick filaments, and thick filament length does not change when cross-bridges cycle. As the Z lines are pulled toward each other, the I band and H zone narrow while the A band stays fixed.

Question 2Exercise Physiology and Anatomy

Which characteristic best describes Type I (slow-twitch) muscle fibers compared with Type II fibers?

  1. Higher myosin ATPase activity
  2. Greater reliance on glycolysis
  3. Greater mitochondrial density Correct answer.
  4. Larger cross-sectional diameter

Explanation

Type I fibers are oxidative fibers with abundant mitochondria, high capillary density, and high fatigue resistance. Type II fibers have larger diameters, faster myosin ATPase kinetics, and greater glycolytic capacity.

Question 3Exercise Physiology and Anatomy

The phosphagen (ATP-PC) system is the predominant source of ATP during which period of maximal exercise?

  1. After 5 minutes of steady work
  2. The first 10 seconds Correct answer.
  3. From 2 to 5 minutes
  4. From 30 seconds to 2 minutes

Explanation

Stored ATP and phosphocreatine supply energy almost instantly but are depleted rapidly, dominating the first several seconds of maximal effort. Beyond roughly 10 seconds, anaerobic glycolysis increasingly contributes, and oxidative phosphorylation dominates longer efforts.

Question 4Exercise Physiology and Anatomy

Cardiac output is calculated as the product of heart rate and which variable?

  1. Stroke volume Correct answer.
  2. Arteriovenous oxygen difference
  3. Mean arterial pressure
  4. Stroke index

Explanation

Cardiac output equals heart rate multiplied by stroke volume, giving the volume of blood ejected per minute. Stroke index and the arteriovenous oxygen difference belong to other calculations.

Question 5Exercise Physiology and Anatomy

A client's stroke volume rises during upright cycling before any change in heart rate occurs. Which mechanism best explains this early increase?

  1. Reduced sympathetic stimulation of the ventricles
  2. Reduced venous return to the right atrium
  3. Greater myocardial stretch from venous return Correct answer.
  4. Heightened systemic vascular resistance

Explanation

The Frank-Starling mechanism states that greater venous return increases end-diastolic volume, stretching the myocardium and producing a stronger contraction. This allows stroke volume to rise even before heart rate climbs.

Question 6Exercise Physiology and Anatomy

According to the Fick equation, if the arteriovenous oxygen difference widens while cardiac output remains constant, what happens to oxygen consumption?

  1. It decreases
  2. It increases Correct answer.
  3. It stays the same
  4. It cannot be predicted

Explanation

The Fick equation states that oxygen consumption equals cardiac output multiplied by the arteriovenous oxygen difference. If cardiac output is unchanged and the difference widens, the product must rise.

Question 7Exercise Physiology and Anatomy

A respiratory exchange ratio of 0.85 during steady-state exercise indicates that the primary fuel source is which of the following?

  1. Predominantly protein
  2. Almost exclusively fat
  3. A mixture of fat and carbohydrate Correct answer.
  4. Almost exclusively carbohydrate

Explanation

An RER of 0.70 reflects nearly pure fat oxidation and 1.00 reflects nearly pure carbohydrate oxidation. A value of 0.85 falls between these anchors, indicating a mixed substrate contribution.

Question 8Exercise Physiology and Anatomy

Which condition shifts the oxyhemoglobin dissociation curve to the right, lowering hemoglobin's affinity for oxygen?

  1. An increase in hydrogen ion concentration Correct answer.
  2. An increase in blood pH
  3. A decrease in the partial pressure of carbon dioxide
  4. A decrease in body temperature

Explanation

The Bohr effect describes how acidosis, elevated carbon dioxide, and higher temperature reduce hemoglobin's oxygen affinity and shift the curve rightward. A higher hydrogen ion concentration is a direct expression of acidosis in the exercising muscle.

Question 9Exercise Physiology and Anatomy

According to the size principle, as force demand rises during a lift, motor units are recruited in which order?

  1. Random order regardless of fiber size
  2. All units activated simultaneously
  3. Large, high-threshold motor units first
  4. Small, low-threshold motor units first Correct answer.

Explanation

The size principle states that motor units are recruited from smallest to largest as force requirements increase. This orderly progression allows fine control at low forces and full recruitment at maximal efforts.

Question 10Exercise Physiology and Anatomy

What is the primary role of the muscle spindle during movement?

  1. Sensing muscle length and rate of stretch Correct answer.
  2. Sensing tension developed within the tendon
  3. Monitoring joint angle at the capsule
  4. Regulating blood flow to the muscle

Explanation

Muscle spindles lie within the muscle belly and respond to changes in length and the speed of that change. This information drives the stretch reflex and contributes to proprioceptive control of movement.

Question 11Exercise Physiology and Anatomy

When a muscle generates very high tension, the Golgi tendon organ contributes to which response?

  1. Reflex inhibition of the contracting muscle Correct answer.
  2. Enhanced contraction of the same muscle group
  3. Increased muscle spindle firing
  4. Vasodilation within the tendon

Explanation

The Golgi tendon organ senses tension and, at high loads, triggers reflex inhibition that reduces force output. This protective mechanism helps limit the risk of tendon and muscle injury.

Question 12Exercise Physiology and Anatomy

Compared with a concentric action at the same load, an eccentric action by the same muscle can produce which of the following?

  1. Greater force with lower metabolic cost Correct answer.
  2. Less force with lower injury risk
  3. Lower force with higher motor unit recruitment
  4. The same force but a greater ATP cost

Explanation

Eccentric actions use fewer motor units to resist a given load, so they generate greater force at a lower metabolic cost. This efficiency is also why eccentric work produces more delayed muscle soreness and damage.

Question 13Exercise Physiology and Anatomy

During moderate-to-vigorous aerobic exercise, blood flow is primarily redirected toward which tissue?

  1. Inactive skeletal muscle
  2. Active skeletal muscle Correct answer.
  3. Renal circulation
  4. Splanchnic circulation

Explanation

Sympathetic vasoconstriction reduces flow to the viscera, kidneys, and inactive muscle during exercise. The resulting blood is shunted to active skeletal muscle, where local vasodilation predominates.

Question 14Exercise Physiology and Anatomy

Which blood pressure response is typical during dynamic aerobic exercise in a healthy adult?

  1. Systolic rises and diastolic changes little Correct answer.
  2. Systolic stays stable while diastolic rises steeply
  3. Systolic and diastolic both fall sharply
  4. Systolic falls and diastolic rises

Explanation

During dynamic exercise, increased cardiac output raises systolic pressure, while peripheral vasodilation in active muscle keeps diastolic pressure nearly unchanged. A steep rise in diastolic pressure is not a normal response and warrants follow-up.

Question 15Exercise Physiology and Anatomy

A client breathes 20 times per minute with a tidal volume of 1.5 L. What is the minute ventilation?

  1. 45 L/min
  2. 3.0 L/min
  3. 15 L/min
  4. 30 L/min Correct answer.

Explanation

Minute ventilation equals breathing frequency multiplied by tidal volume. Multiplying 20 breaths per minute by 1.5 L per breath gives 30 L per minute.

Question 16Exercise Physiology and Anatomy

The lactate threshold is best defined as the exercise intensity at which which of the following occurs?

  1. Blood lactate rises steadily above resting values Correct answer.
  2. Lactate production first begins within the exercising muscle
  3. Blood lactate reaches 10 mmol/L
  4. Pulmonary ventilation begins to fall

Explanation

The lactate threshold is the intensity at which blood lactate begins a sustained rise above resting concentrations. It reflects the point where lactate appearance exceeds clearance and is used to set training and testing intensities.

Question 17Exercise Physiology and Anatomy

In the normal heart, the electrical impulse that initiates each contraction originates in which structure?

  1. Purkinje fibers
  2. Sinoatrial node Correct answer.
  3. Bundle of His
  4. Atrioventricular node

Explanation

The sinoatrial node has the highest intrinsic rate of spontaneous depolarization and therefore sets the normal heart rhythm. Its impulse spreads through the atria before reaching the atrioventricular node.

Question 18Exercise Physiology and Anatomy

Which substance accumulates as the end product of anaerobic glycolysis during high-intensity exercise?

  1. Acetyl-CoA
  2. Lactate Correct answer.
  3. Carbon dioxide
  4. Pyruvate only

Explanation

When glycolytic flux outpaces mitochondrial oxidation, pyruvate is converted to lactate by lactate dehydrogenase. This reaction regenerates NAD+ so glycolysis can continue.

Question 19Exercise Physiology and Anatomy

The knee is classified as which type of joint?

  1. Cartilaginous (symphysis)
  2. Ball-and-socket
  3. Fibrous (suture)
  4. Synovial (hinge) Correct answer.

Explanation

The knee is a synovial joint whose primary motion is flexion and extension in one plane. Synovial joints are characterized by a joint cavity, articular cartilage, and a synovial membrane.

Question 20Exercise Physiology and Anatomy

An activity performed at 5 METs requires approximately how many milliliters of oxygen per kilogram per minute?

  1. 5.0 mL/kg/min
  2. 10.5 mL/kg/min
  3. 17.5 mL/kg/min Correct answer.
  4. 14.0 mL/kg/min

Explanation

One MET is defined as 3.5 mL/kg/min of oxygen consumption at rest. Multiplying 5 METs by 3.5 mL/kg/min yields 17.5 mL/kg/min.

Question 21Exercise Physiology and Anatomy

On the sarcomere length-tension curve, active tension is greatest when which condition exists?

  1. The sarcomere is fully stretched with no filament overlap
  2. The sarcomere is shortened to half its resting length
  3. Thin filaments overlap each other at the sarcomere center
  4. Optimal overlap exists between the filaments Correct answer.

Explanation

Maximal tension develops at the sarcomere length where actin and myosin overlap enough to form the greatest number of cross-bridges. Overstretching eliminates overlap, and over-shortening causes filament interference.

Question 22Exercise Physiology and Anatomy

A client has a tidal volume of 600 mL and a dead space of 150 mL. What is the alveolar ventilation per breath?

  1. 600 mL
  2. 450 mL Correct answer.
  3. 150 mL
  4. 750 mL

Explanation

Alveolar ventilation per breath equals tidal volume minus dead space volume. Subtracting 150 mL from 600 mL leaves 450 mL reaching the alveoli for gas exchange.

Question 23Exercise Physiology and Anatomy

During prolonged intense exercise in the heat, plasma volume typically falls. What is the most direct consequence for measured blood variables?

  1. Hematocrit rises Correct answer.
  2. Serum sodium concentration falls
  3. Red cell count falls
  4. Hemoglobin concentration falls

Explanation

Sweat losses reduce plasma water, concentrating the cellular and solute components of blood. Hematocrit therefore rises even though the absolute number of red cells has not changed.

Question 24Exercise Physiology and Anatomy

The ventilatory threshold during incremental exercise is most closely linked to which of the following?

  1. A progressive decrease in carbon dioxide production
  2. A rising blood lactate and CO2 production Correct answer.
  3. A decrease in respiratory rate
  4. A falling blood lactate concentration

Explanation

As lactate accumulates, it is buffered by bicarbonate, generating additional carbon dioxide that stimulates ventilation. The disproportionate rise in ventilation relative to oxygen uptake marks the ventilatory threshold.

Question 25Exercise Physiology and Anatomy

According to Poiseuille's law, if the radius of a blood vessel doubles while other factors stay constant, resistance to flow does which of the following?

  1. Remains unchanged
  2. Decreases about 2-fold
  3. Increases about 4-fold
  4. Decreases about 16-fold Correct answer.

Explanation

Poiseuille's law states that resistance is inversely proportional to the fourth power of the vessel radius. Doubling the radius raises the denominator by a factor of 2^4, or 16, so resistance falls about 16-fold.

Question 26Exercise Physiology and Anatomy

Which characteristic best describes Type I skeletal muscle fibers?

  1. Short contraction time and high ATPase activity
  2. High oxidative capacity and fatigue resistance Correct answer.
  3. Large cross-sectional area and rapid force production
  4. Predominantly glycolytic with low capillary density

Explanation

Type I slow-twitch fibers have high mitochondrial density, capillary supply, and myoglobin content, which supports fatigue-resistant endurance work. Their reliance on oxidative metabolism allows sustained activity.

Question 27Exercise Physiology and Anatomy

Which neurotransmitter is released at the neuromuscular junction to depolarize the muscle fiber?

  1. Dopamine
  2. Gamma-aminobutyric acid
  3. Acetylcholine Correct answer.
  4. Norepinephrine

Explanation

The motor neuron releases acetylcholine into the synaptic cleft, where it binds to nicotinic receptors on the motor end plate. This binding increases sodium permeability and initiates the action potential that leads to contraction.

Question 28Exercise Physiology and Anatomy

Abduction of the arm occurs primarily in which plane of motion?

  1. Oblique plane
  2. Transverse plane
  3. Frontal plane Correct answer.
  4. Sagittal plane

Explanation

Abduction moves a limb away from the midline in the frontal plane. Sagittal-plane motion includes flexion and extension, while transverse-plane motion includes rotation.

Question 29Exercise Physiology and Anatomy

A client has a heart rate of 70 beats per minute and a stroke volume of 70 mL per beat. What is the cardiac output?

  1. 0.7 L/min
  2. 3.5 L/min
  3. 7.0 L/min
  4. 4.9 L/min Correct answer.

Explanation

Cardiac output equals heart rate multiplied by stroke volume. Multiplying 70 beats/min by 70 mL/beat gives 4,900 mL/min, or 4.9 L/min.

Question 30Exercise Physiology and Anatomy

The mitral valve separates which two chambers of the heart?

  1. Right atrium and right ventricle
  2. Left atrium and left ventricle Correct answer.
  3. Right ventricle and pulmonary trunk
  4. Left ventricle and aorta

Explanation

The mitral, or bicuspid, valve lies between the left atrium and left ventricle and prevents backflow during ventricular systole. The tricuspid valve occupies the right side, and the semilunar valves guard ventricular outflow.

Question 31Exercise Physiology and Anatomy

The ATP-phosphocreatine system is the predominant energy source for activities lasting approximately how long?

  1. 30 to 60 seconds
  2. 2 to 3 minutes
  3. 6 to 10 seconds Correct answer.
  4. More than 5 minutes

Explanation

The phosphagen system supplies ATP very rapidly but has a small capacity, dominating brief maximal efforts of roughly 10 seconds or less. Anaerobic glycolysis becomes more important as efforts extend toward 30 to 60 seconds.

Question 32Exercise Physiology and Anatomy

In healthy adults at rest, the majority of oxygen in arterial blood is transported in which form?

  1. Dissolved in plasma
  2. Bound to albumin
  3. Bound to hemoglobin Correct answer.
  4. Converted to carbonic acid

Explanation

About 98% of arterial oxygen is carried bound to hemoglobin, with only a small fraction dissolved in plasma. Hemoglobin binding greatly increases the blood's oxygen-carrying capacity.

Question 33Exercise Physiology and Anatomy

Which structure contains the primary respiratory rhythm generator?

  1. Medulla oblongata Correct answer.
  2. Hypothalamus
  3. Cerebellum
  4. Carotid bodies

Explanation

Respiratory rhythm is generated by neural networks in the medulla oblongata, with modulation from the pons and higher centers. Carotid bodies sense blood gases but do not generate the rhythm.

Question 34Exercise Physiology and Anatomy

An increase in venous return to the heart, with no change in contractility, produces which immediate effect?

  1. Decreased stroke volume
  2. Increased systemic vascular resistance
  3. Decreased heart rate
  4. Increased stroke volume Correct answer.

Explanation

According to the Frank-Starling mechanism, greater venous return increases end-diastolic volume and stretches the myocardium. The stretched fibers contract more forcefully, increasing stroke volume.

Question 35Exercise Physiology and Anatomy

Compared with a parallel-fibered muscle of similar volume, a pennate muscle generally has which property?

  1. Equal force with equal shortening
  2. Greater range of motion with equal force
  3. Greater range of motion with lower force
  4. Greater force with less shortening Correct answer.

Explanation

Pennate fibers attach at an angle to the tendon, allowing more fibers per unit of cross-sectional area and greater force production. The trade-off is a smaller change in length and therefore less range of shortening.

Question 36Exercise Physiology and Anatomy

Which energy system is the major contributor during a maximal 400-meter sprint?

  1. ATP-phosphocreatine system exclusively
  2. Aerobic oxidation
  3. Anaerobic glycolysis Correct answer.
  4. Beta-oxidation of fatty acids

Explanation

A maximal 400-meter sprint lasts roughly 50 to 60 seconds, so anaerobic glycolysis supplies most of the ATP after the initial phosphagen contribution. Aerobic metabolism contributes but is not the major source at this intensity and duration.

Question 37Exercise Physiology and Anatomy

After strenuous exercise, oxygen consumption remains elevated above resting values for a period. This is termed which of the following?

  1. Anaerobic threshold
  2. Steady state
  3. Oxygen deficit
  4. EPOC Correct answer.

Explanation

Excess postexercise oxygen consumption, or EPOC, is the elevated oxygen uptake that persists after exercise ends. It supports replenishment of phosphocreatine, restoration of oxygen stores, and other recovery processes.

Question 38Exercise Physiology and Anatomy

A client holds a plank position without moving for 30 seconds. Which muscle action predominates?

  1. Concentric
  2. Eccentric
  3. Plyometric
  4. Isometric Correct answer.

Explanation

Isometric contractions generate tension without a change in muscle length or joint angle. Holding a stable plank requires continuous tension while posture is maintained.

Question 39Exercise Physiology and Anatomy

Vital capacity equals total lung capacity minus which volume?

  1. Inspiratory reserve volume
  2. Tidal volume
  3. Residual volume Correct answer.
  4. Expiratory reserve volume

Explanation

Vital capacity is the sum of tidal, inspiratory reserve, and expiratory reserve volumes. Because residual volume cannot be exhaled, it is excluded, making vital capacity equal to total lung capacity minus residual volume.

Question 40Exercise Physiology and Anatomy

During exercise in a hot, dry environment, which mechanism accounts for the greatest amount of heat loss?

  1. Conduction
  2. Evaporation Correct answer.
  3. Convection
  4. Radiation

Explanation

Evaporation of sweat becomes the dominant heat-loss pathway during exercise in hot environments, especially when the air is dry. Radiation, conduction, and convection depend on temperature gradients and airflow and become less effective as ambient temperature approaches skin temperature.

Question 41Exercise Physiology and Anatomy

Rhythmic skeletal muscle contractions assist venous return primarily by which action?

  1. Increasing arterial pressure
  2. Compressing veins with one-way valves Correct answer.
  3. Reducing blood viscosity
  4. Dilating resistance arteries

Explanation

The muscle pump compresses veins during contraction and relies on one-way valves to prevent backflow. This milks blood toward the heart and enhances venous return during rhythmic exercise.

Question 42Exercise Physiology and Anatomy

Plasma epinephrine rises during moderate-to-vigorous exercise. What is a primary cardiovascular effect?

  1. Increases heart rate and contractility Correct answer.
  2. Decreases lipolysis in adipose tissue
  3. Vasoconstricts all systemic vessels
  4. Reduces hepatic glycogenolysis

Explanation

Epinephrine acts on beta-adrenergic receptors to increase heart rate and myocardial contractility. It also supports glycogenolysis and lipolysis and helps redistribute blood flow, rather than uniformly constricting all vessels.

Question 43Exercise Physiology and Anatomy

Resistance training increases muscle size primarily by which mechanism?

  1. Reducing the number of satellite cells
  2. Adding contractile proteins within existing fibers Correct answer.
  3. Converting type I fibers into cardiac muscle
  4. Increasing the number of muscle fibers through hyperplasia

Explanation

Human skeletal muscle hypertrophy occurs mainly through increased myofibrillar protein synthesis within existing fibers. Fiber hyperplasia is not considered a major contributor to resistance-training-induced growth in humans.

Question 44Exercise Physiology and Anatomy

After several weeks of bed rest, which change is most expected?

  1. Higher mitochondrial density
  2. Greater capillary density
  3. Lower VO2max and oxidative enzymes Correct answer.
  4. Higher stroke volume

Explanation

Detraining reduces maximal oxygen uptake, oxidative enzyme activity, capillary density, and stroke volume. These losses reflect reduced cardiovascular and skeletal muscle oxidative capacity with inactivity.

Question 45Exercise Physiology and Anatomy

Within a single motor unit, how is force increased?

  1. Increasing the frequency of action potentials reaching the unit Correct answer.
  2. Reducing calcium release from the sarcoplasmic reticulum
  3. Recruiting additional fibers within the same unit
  4. Converting fast-twitch fibers to slow-twitch fibers

Explanation

A motor unit fires in an all-or-none manner, so all its fibers are activated together when recruited. Greater force from that unit is achieved through rate coding, meaning a higher frequency of action potentials and fused tetanic tension.

Question 46Exercise Physiology and Anatomy

The biceps brachii flexing the elbow with a dumbbell is an example of which lever class?

  1. First-class lever
  2. Fourth-class lever
  3. Second-class lever
  4. Third-class lever Correct answer.

Explanation

In a third-class lever, the effort is applied between the fulcrum and the load. The biceps insertion lies between the elbow joint and the hand-held dumbbell, favoring speed and range of motion at the expense of force.

Question 47Exercise Physiology and Anatomy

During muscle shortening, which sarcomere component maintains a constant length?

  1. Sarcomere length
  2. A band Correct answer.
  3. H zone
  4. I band

Explanation

The A band corresponds to the length of the thick myosin filaments, which do not shorten during contraction. The I band and H zone narrow as actin filaments slide inward and overlap increases.

Question 48Exercise Physiology and Anatomy

During the first few days at high altitude, which change contributes to a rise in hematocrit?

  1. Increased plasma volume
  2. Immediate increase in red blood cell mass
  3. Decreased plasma volume Correct answer.
  4. Decreased erythropoietin secretion

Explanation

Plasma volume falls within the first days of altitude exposure, producing hemoconcentration and a higher hematocrit. Red blood cell mass increases only after weeks of elevated erythropoietin stimulation.

Question 49Exercise Physiology and Anatomy

During dynamic exercise, the arterial baroreflex primarily does which of the following?

  1. It is completely suppressed so pressure can rise
  2. It holds the pressure set point at resting values
  3. It triggers a dominant parasympathetic response
  4. It resets to a higher operating pressure Correct answer.

Explanation

The baroreflex resets to a higher operating point during exercise, allowing blood pressure to rise while still buffering rapid fluctuations. It is not abolished; rather, its set point is adjusted to meet exercise demands.

Question 50Exercise Physiology and Anatomy

The stretch-shortening cycle enhances force production primarily through which mechanism?

  1. Elastic energy storage plus stretch reflex Correct answer.
  2. Increased muscle temperature
  3. Accumulation of lactic acid
  4. Reduced motor unit recruitment

Explanation

During the eccentric stretch of the stretch-shortening cycle, elastic energy is stored in tendons and connective tissue and the stretch reflex increases muscle activation. This stored energy and reflex contribution augment the subsequent concentric force.