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NCAA CPL Human Performance study materials
NCAA CPL Human Performance study resources

NCAA CPL Human Performance practice questions

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Question 1Anatomy and Physiology of Human Movement

During a 100 m sprint, which muscle action occurs at the hip extensors as the leg drives backward against the ground during late stance?

  1. Passive stretch without tension
  2. Eccentric contraction
  3. Isometric contraction
  4. Concentric contraction Correct answer.

Explanation

In late stance the hip extensors shorten while generating force to extend the hip and propel the body forward, which defines a concentric action. Eccentric action would involve lengthening under tension, and isometric action produces no joint motion. The propulsive drive requires active shortening, not passive lengthening.

Question 2Anatomy and Physiology of Human Movement

Which muscle is the primary eccentric controller of knee flexion during the loading response of gait?

  1. Quadriceps group via the vastus muscles Correct answer.
  2. Iliopsoas
  3. Biceps femoris
  4. Rectus femoris

Explanation

As the knee flexes slightly after initial contact, the quadriceps lengthen under tension to control the rate of flexion and absorb impact, making this an eccentric action of the knee extensors. The hamstrings assist but are not the primary controller of this knee flexion moment. The iliopsoas acts at the hip rather than controlling knee flexion.

Question 3Anatomy and Physiology of Human Movement

A muscle fiber with a high proportion of Type I myosin heavy chain is best characterized by which property?

  1. Large cross-sectional area and low capillary density
  2. High glycolytic capacity and rapid fatigue
  3. Slow contraction velocity and high fatigue resistance Correct answer.
  4. Predominant reliance on phosphocreatine stores

Explanation

Type I fibers have a slow myosin ATPase isoform, dense capillarization, and high mitochondrial content, giving them slow contraction speed with strong fatigue resistance. Fast-twitch fibers, by contrast, favor glycolysis and phosphocreatine for rapid force. Cross-sectional area and glycolytic capacity are not the defining features of slow fibers.

Question 4Anatomy and Physiology of Human Movement

According to the sliding filament theory, what directly triggers the release of calcium from the sarcoplasmic reticulum?

  1. Attachment of troponin to actin
  2. Binding of ATP to the myosin head
  3. Shortening of the sarcomere below resting length
  4. Arrival of an action potential at the T-tubule and depolarization of the terminal cisternae Correct answer.

Explanation

Depolarization spreads along the T-tubules and activates voltage-sensitive receptors that open calcium channels in the terminal cisternae of the sarcoplasmic reticulum. Calcium then binds troponin C, shifting tropomyosin to expose actin binding sites. ATP binding to myosin drives cross-bridge detachment, not calcium release.

Question 5Anatomy and Physiology of Human Movement

Which structure transmits force from the muscle-tendon unit directly to the periosteum of bone?

  1. Sarcolemma
  2. Endomysium
  3. Tendon enthesis Correct answer.
  4. Fascicle

Explanation

The enthesis is the specialized insertion region where tendon fibers blend into bone, transmitting tensile load to the periosteum and underlying bone. The sarcolemma is the muscle cell membrane, the endomysium wraps individual fibers, and a fascicle is a bundle of fibers. Only the enthesis serves as the direct tendon-to-bone interface.

Question 6Anatomy and Physiology of Human Movement

During a biceps curl, the elbow flexors shorten while the elbow extends slightly during the lowering phase. Which statement best describes the elbow extensor action during the lowering phase?

  1. The triceps contract concentrically to lower the forearm
  2. The biceps act concentrically during lowering
  3. The triceps act eccentrically to control elbow extension Correct answer.
  4. The brachialis acts isometrically to prevent movement

Explanation

Lowering the forearm against gravity requires the elbow extensors to lengthen under tension, which is an eccentric action that controls the rate of extension. Concentric triceps action would accelerate extension rather than control it. The biceps are lengthening, not shortening, during the lowering phase.

Question 7Anatomy and Physiology of Human Movement

Which plane and axis best describe the primary motion of shoulder abduction?

  1. Transverse plane about a vertical axis
  2. Sagittal plane about a frontal axis
  3. Frontal plane about a sagittal axis Correct answer.
  4. Sagittal plane about a vertical axis

Explanation

Shoulder abduction moves the arm away from the midline in the frontal (coronal) plane, rotating about an anteroposterior (sagittal) axis. Sagittal plane motion describes flexion and extension. Transverse plane motion describes horizontal rotation about a vertical axis.

Question 8Anatomy and Physiology of Human Movement

In a closed kinetic chain exercise such as a squat, the movement of the tibia relative to the femur during knee flexion is best described as which?

  1. Tibia rotating posteriorly on a fixed femur Correct answer.
  2. Femur rotating anteriorly on a fixed tibia
  3. Tibia translating anteriorly on the femur
  4. Patella translating posteriorly on the femur

Explanation

In a closed chain the distal segment is fixed, so knee flexion is produced largely by the femur moving on the tibia, with the tibia rotating posteriorly relative to the femur. Open chain motion instead involves the tibia moving on a fixed femur. Anterior tibial translation is restrained by the ACL and is not the flexion mechanism.

Question 9Anatomy and Physiology of Human Movement

Which muscle acts as the primary hip flexor during the swing phase of gait?

  1. Gluteus maximus
  2. Iliopsoas Correct answer.
  3. Biceps femoris
  4. Gastrocnemius

Explanation

The iliopsoas is the strongest hip flexor and initiates limb advancement during swing. Gluteus maximus is a hip extensor, biceps femoris is a knee flexor and hip extensor, and gastrocnemius acts at the ankle and knee. Only iliopsoas is primarily responsible for hip flexion in swing.

Question 10Anatomy and Physiology of Human Movement

Which type of joint permits the greatest triplanar motion and is exemplified by the glenohumeral joint?

  1. Pivot joint
  2. Ball-and-socket joint Correct answer.
  3. Hinge joint
  4. Saddle joint

Explanation

A ball-and-socket joint has spherical articular surfaces that allow motion in all three planes, including flexion, abduction, and rotation. Hinge joints permit motion in one plane, pivot joints allow rotation only, and saddle joints allow two planes with limited rotation. The shoulder and hip are the classic ball-and-socket examples.

Question 11Anatomy and Physiology of Human Movement

During a maximal vertical jump, which sequence of muscle actions best describes the ankle during the countermovement and push-off phases?

  1. Concentric then eccentric
  2. Eccentric then isometric
  3. Eccentric then concentric Correct answer.
  4. Isometric then eccentric

Explanation

The countermovement involves dorsiflexion as the plantarflexors lengthen under tension, which is an eccentric action that stores elastic energy. Push-off then requires rapid shortening of the plantarflexors, a concentric action. This stretch-shortening sequence enhances force output.

Question 12Anatomy and Physiology of Human Movement

Which factor most directly determines the maximal active tension a single muscle fiber can generate at optimal length?

  1. The length of the tendon
  2. The velocity of sarcomere shortening
  3. The number of cross-bridges formed between actin and myosin Correct answer.
  4. The number of motor units in the muscle

Explanation

Active tension depends on cross-bridge formation, which is maximal when actin and myosin overlap optimally. At lengths too short or too long, fewer cross-bridges form and tension declines. Tendon length and motor unit number affect whole-muscle force but not the fiber-level cross-bridge mechanism.

Question 13Anatomy and Physiology of Human Movement

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

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

Explanation

Motor neurons release acetylcholine into the synaptic cleft, where it binds nicotinic receptors on the motor end plate and triggers depolarization. Norepinephrine and dopamine are catecholamines used elsewhere in the nervous system, and GABA is inhibitory. Acetylcholine is the specific transmitter at the neuromuscular junction.

Question 14Anatomy and Physiology of Human Movement

A muscle crossing two joints can be limited in its ability to produce full range motion at both joints simultaneously. Which term describes this phenomenon?

  1. Length-tension deficit
  2. Active insufficiency Correct answer.
  3. Passive tension
  4. Reciprocal inhibition

Explanation

Active insufficiency occurs when a multi-joint muscle shortens to the point that it can no longer generate effective tension at both joints simultaneously. For example, full knee flexion and hip extension limit hamstring force production. Passive insufficiency, by contrast, occurs when the muscle is stretched to its limit.

Question 15Anatomy and Physiology of Human Movement

Which structure is the primary stabilizer preventing anterior translation of the tibia on the femur?

  1. Posterior cruciate ligament
  2. Patellar tendon
  3. Medial collateral ligament
  4. Anterior cruciate ligament Correct answer.

Explanation

The anterior cruciate ligament resists anterior tibial translation and limits tibial internal rotation. The posterior cruciate ligament resists posterior translation, the medial collateral ligament resists valgus stress, and the patellar tendon transmits quadriceps force. Only the ACL provides the primary restraint to anterior tibial translation.

Question 16Anatomy and Physiology of Human Movement

During a push-up performed on a stable surface, the elbow extensors shorten to raise the body. Which kinematic chain classification applies?

  1. Closed kinetic chain Correct answer.
  2. Isokinetic chain
  3. Hybrid chain
  4. Open kinetic chain

Explanation

In a push-up, the hands are fixed against the ground while the body moves, so the distal segment is stationary and the proximal segment moves, which defines a closed kinetic chain. An open chain would involve the distal segment moving freely. Hybrid and isokinetic are not standard chain classifications.

Question 17Anatomy and Physiology of Human Movement

Which muscle group produces the primary plantarflexion moment during the push-off phase of running?

  1. Peroneus longus
  2. Extensor digitorum longus
  3. Triceps surae Correct answer.
  4. Tibialis anterior

Explanation

The triceps surae, comprising the gastrocnemius and soleus, generates the dominant plantarflexion moment during push-off. The tibialis anterior and extensor digitorum longus are dorsiflexors, and the peroneus longus primarily everts the foot. Only the triceps surae provides the primary plantarflexion force.

Question 18Anatomy and Physiology of Human Movement

Which statement best explains why a muscle produces less force during rapid shortening than during isometric contraction?

  1. The muscle fiber diameter increases during shortening
  2. More motor units are recruited during rapid shortening
  3. Calcium release increases with shortening velocity
  4. Fewer cross-bridges remain attached at high shortening velocity Correct answer.

Explanation

At high shortening velocity, cross-bridges detach faster than they can reattach, reducing the number of force-producing attachments at any moment. This is the basis of the force-velocity relationship. Motor unit recruitment and fiber diameter do not increase with velocity, and calcium release is not enhanced by faster shortening.

Question 19Anatomy and Physiology of Human Movement

Which bone landmark serves as the origin for the gastrocnemius?

  1. Posterior surface of the tibia
  2. Calcaneus
  3. Femoral condyles Correct answer.
  4. Head of the fibula

Explanation

The gastrocnemius originates from the posterior aspects of the femoral condyles, which is why it crosses the knee joint and assists knee flexion. The soleus originates from the posterior tibia and fibula, and the calcaneus is the insertion site via the Achilles tendon. The fibular head is an origin for several other muscles but not the gastrocnemius.

Question 20Anatomy and Physiology of Human Movement

A client performs a lateral lunge, moving the right leg out to the side. Which hip motion occurs at the right hip as the leg abducts?

  1. Hip abduction Correct answer.
  2. Hip adduction
  3. Hip internal rotation
  4. Hip extension

Explanation

Moving the leg away from the midline in the frontal plane is hip abduction, produced by the gluteus medius and minimus. Adduction brings the limb toward the midline, internal rotation occurs in the transverse plane, and extension occurs in the sagittal plane. The lateral lunge therefore requires right hip abduction.

Question 21Anatomy and Physiology of Human Movement

Which muscle is the primary contributor to hip abduction and is tested with the patient in side-lying?

  1. Gluteus medius Correct answer.
  2. Gluteus maximus
  3. Piriformis
  4. Adductor magnus

Explanation

The gluteus medius is the primary hip abductor and is isolated in a side-lying manual muscle test against gravity. Gluteus maximus extends the hip, adductor magnus adducts the hip, and the piriformis is an external rotator. Only the gluteus medius is the primary abductor.

Question 22Anatomy and Physiology of Human Movement

Which structure forms the boundary between the epimysium and the surrounding fascia and allows muscle gliding?

  1. Tendon sheath
  2. Endomysium
  3. Epimysium outer surface Correct answer.
  4. Perimysium

Explanation

The epimysium is the dense connective tissue sheath enclosing the entire muscle, and its outer surface interfaces with surrounding fascia to permit gliding between muscles. The perimysium surrounds fascicles and the endomysium surrounds individual fibers. A tendon sheath encloses tendons, not the muscle belly.

Question 23Anatomy and Physiology of Human Movement

During the descent phase of a squat, which muscle action occurs at the quadriceps?

  1. Isometric contraction
  2. Concentric contraction
  3. Passive lengthening without tension
  4. Eccentric contraction Correct answer.

Explanation

As the knees flex under load during the descent, the quadriceps lengthen while generating tension to control the rate of flexion, which is an eccentric action. Concentric action would occur during the ascent as the knees extend. Isometric action produces no joint motion.

Question 24Anatomy and Physiology of Human Movement

Which statement accurately describes the relationship between motor unit size and fine motor control?

  1. Motor unit size has no relationship to control precision
  2. Fine control depends only on muscle fiber type
  3. Large motor units with many fibers per neuron allow fine control
  4. Small motor units with few fibers per neuron allow fine control Correct answer.

Explanation

Small motor units, with a low innervation ratio, allow graded force and precise control, as seen in the extraocular and hand muscles. Large motor units produce coarse, powerful contractions and are suited to gross movement. Control precision therefore depends on innervation ratio rather than fiber type alone.

Question 25Anatomy and Physiology of Human Movement

Which joint motion is described as rotation of the scapula so the glenoid faces upward, allowing arm elevation above shoulder height?

  1. Scapular retraction
  2. Scapular protraction
  3. Scapular depression
  4. Scapular upward rotation Correct answer.

Explanation

Upward rotation of the scapula tilts the glenoid upward and is essential for raising the arm above shoulder level, driven by the trapezius and serratus anterior. Retraction and protraction occur in the transverse plane, and depression lowers the scapula. Only upward rotation enables full overhead elevation.

Question 26Anatomy and Physiology of Human Movement

Which muscle fiber type is characterized by a high oxidative capacity, a dense capillary supply, and resistance to fatigue, making it dominant in postural muscles?

  1. Type IIa fast-twitch fibers
  2. Type IIx fast-twitch fibers
  3. Type IIb fast-twitch fibers
  4. Type I slow-twitch fibers Correct answer.

Explanation

Type I fibers rely on aerobic metabolism, contain abundant mitochondria and myoglobin, and are recruited for sustained low-force activity such as posture. Their high fatigue resistance, not peak force output, distinguishes them from fast-twitch subtypes.

Question 27Anatomy and Physiology of Human Movement

Which property of skeletal muscle describes its ability to return to resting length after being stretched?

  1. Elasticity Correct answer.
  2. Excitability
  3. Contractility
  4. Extensibility

Explanation

Elasticity is the capacity of muscle tissue to recoil to its original length after deformation, a property contributed by titin and connective tissue elements. It is distinct from extensibility, which is the ability to be lengthened.

Question 28Anatomy and Physiology of Human Movement

A sarcomere is best described as which structure?

  1. The plasma membrane of a single muscle fiber
  2. The functional contractile unit between two Z-lines Correct answer.
  3. The junction where a motor neuron meets a fiber
  4. The connective tissue sheath surrounding a whole muscle

Explanation

The sarcomere is the repeating segment of myofilaments bounded by adjacent Z-lines and is the smallest unit capable of producing force through actin-myosin interaction. Its length determines the overlap between thick and thin filaments.

Question 29Anatomy and Physiology of Human Movement

Which description correctly matches the anatomical position convention used to define joint motion?

  1. Palms facing posteriorly with arms at the sides
  2. Standing upright with palms facing forward and thumbs lateral Correct answer.
  3. Seated with hips and knees flexed to 90 degrees
  4. Standing with feet together and arms crossed

Explanation

In the standard anatomical position the body is upright, feet slightly apart, arms at the sides, and palms facing anteriorly so the thumbs point laterally. All planar joint motions are named relative to this reference.

Question 30Anatomy and Physiology of Human Movement

During the upward phase of a standing calf raise, the ankle moves from a dorsiflexed position into plantarflexion against body weight. Which muscle action and plane best describe this?

  1. Isometric dorsiflexion in the transverse plane
  2. Concentric dorsiflexion in the sagittal plane
  3. Eccentric plantarflexion in the frontal plane
  4. Concentric plantarflexion in the sagittal plane Correct answer.

Explanation

Raising the heel shortens the plantarflexors against resistance, which is a concentric action, and ankle motion occurs in the sagittal plane about a frontal axis. Dorsiflexion would be the opposite motion.

Question 31Anatomy and Physiology of Human Movement

A client holds a side plank with the hip abducted and stabilized against gravity for 30 seconds without moving. Which muscle action is occurring at the hip abductors?

  1. Concentric shortening
  2. Isometric contraction Correct answer.
  3. Passive stretching
  4. Eccentric lengthening

Explanation

Holding a fixed position against gravity requires tension without a change in muscle length, which defines an isometric contraction. The abductors are generating force to maintain the pelvis level.

Question 32Anatomy and Physiology of Human Movement

Which sequence correctly describes the events of excitation-contraction coupling in skeletal muscle?

  1. Cross-bridges form, acetylcholine binds, calcium binds troponin, tropomyosin shifts
  2. Acetylcholine binds, tropomyosin shifts, calcium is released from the sarcoplasmic reticulum, cross-bridges form
  3. Calcium binds troponin, acetylcholine binds, cross-bridges form, calcium is released from the sarcoplasmic reticulum
  4. Acetylcholine binds, calcium is released from the sarcoplasmic reticulum, calcium binds troponin, tropomyosin shifts, cross-bridges form Correct answer.

Explanation

Depolarization triggers acetylcholine release at the neuromuscular junction, and the resulting action potential causes calcium release from the sarcoplasmic reticulum. Calcium then binds troponin, displacing tropomyosin to expose actin binding sites so cross-bridges can cycle.

Question 33Anatomy and Physiology of Human Movement

A muscle is stretched to 150 percent of its resting length before contraction. What is the most likely effect on active force production?

  1. Active force is unchanged because fiber number is constant
  2. Active force decreases because actin-myosin overlap is reduced Correct answer.
  3. Active force increases because elastic recoil adds to tension
  4. Active force increases because more calcium is released

Explanation

Active tension depends on the number of actin-myosin cross-bridges that can form, which is maximal at an optimal overlap length. Overstretching pulls thick and thin filaments apart, reducing available binding sites and lowering active force.

Question 34Anatomy and Physiology of Human Movement

Which statement best describes the role of the antagonist muscle during a controlled movement?

  1. It lengthens or maintains tension to control and refine the movement Correct answer.
  2. It contracts concentrically to assist the prime mover
  3. It generates the primary force for the joint motion
  4. It relaxes completely so no tension is present

Explanation

The antagonist opposes the prime mover and typically lengthens under eccentric control or holds tension to regulate speed and joint stability. Reciprocal inhibition reduces but does not eliminate its activity.

Question 35Anatomy and Physiology of Human Movement

A client performs a seated row and retracts the scapula by pulling the shoulder blades toward the spine. Which muscle is the primary mover for this scapular retraction?

  1. Levator scapulae
  2. Pectoralis minor
  3. Rhomboid major Correct answer.
  4. Serratus anterior

Explanation

The rhomboids run from the spinous processes to the medial border of the scapula and pull it toward the vertebral column, making them primary retractors. The trapezius middle fibers also assist retraction.

Question 36Anatomy and Physiology of Human Movement

A sprinter pushes off the starting block, driving the hip into extension while the knee extends. Which muscle group is the primary contributor to hip extension in this action?

  1. Gluteus maximus and hamstrings Correct answer.
  2. Tensor fasciae latae and adductor longus
  3. Iliopsoas
  4. Rectus femoris and sartorius

Explanation

Hip extension is driven primarily by the gluteus maximus with substantial contribution from the hamstrings, which cross the hip posteriorly. These muscles generate the propulsive force during push-off.

Question 37Anatomy and Physiology of Human Movement

During a dumbbell lateral raise, the arm is lifted from the side of the body to shoulder height. Which motion and prime mover pair is correct?

  1. Shoulder adduction, primarily latissimus dorsi
  2. Shoulder extension, primarily posterior deltoid
  3. Shoulder abduction, primarily deltoid middle fibers Correct answer.
  4. Shoulder flexion, primarily anterior deltoid

Explanation

Lifting the arm away from the body in the frontal plane is shoulder abduction, and the middle deltoid is the primary mover, assisted by the supraspinatus. The motion occurs about an anterior-posterior axis.

Question 38Anatomy and Physiology of Human Movement

A muscle that crosses both the hip and the knee can be limited in producing full range motion at both joints at once. Which term describes this limitation?

  1. Passive insufficiency
  2. Active insufficiency Correct answer.
  3. Reciprocal inhibition
  4. Length-tension deficit

Explanation

Active insufficiency occurs when a multi-joint muscle shortens so much across both joints that it can no longer generate effective tension. Passive insufficiency, by contrast, occurs when the muscle is stretched to its limit across both joints.

Question 39Anatomy and Physiology of Human Movement

During steady-state submaximal exercise, cardiac output rises mainly through increases in both heart rate and stroke volume. Which statement best explains the contribution of stroke volume to this response?

  1. Stroke volume falls as heart rate rises so cardiac output stays constant
  2. Stroke volume rises through increased venous return and enhanced contractility, then plateaus at higher intensities Correct answer.
  3. Stroke volume increases without limit as intensity rises to maximal effort
  4. Stroke volume is unaffected by training status or body position

Explanation

Greater venous return from the muscle pump and sympathetic stimulation increase end-diastolic volume and contractility, raising stroke volume early in exercise. At higher intensities stroke volume tends to plateau while heart rate continues to drive cardiac output upward.

Question 40Anatomy and Physiology of Human Movement

A coach observes that a client can lift more weight when the movement is performed slowly and with a pause than when it is performed explosively. Which explanation fits the force-velocity relationship?

  1. Force output is greatest during fast concentric shortening
  2. Force output is independent of contraction velocity
  3. Force output is greatest at zero or near-zero shortening velocity Correct answer.
  4. Force output is greatest during passive lengthening only

Explanation

The force-velocity relationship shows that concentric force declines as shortening velocity increases, so maximal force occurs near isometric conditions. A slow or paused lift therefore permits greater force than an explosive one.

Question 41Exercise Physiology and Energy Systems

During a maximal-effort sprint lasting roughly 6 seconds, which energy system supplies the majority of ATP?

  1. The phosphagen system using stored creatine phosphate Correct answer.
  2. The Cori cycle recycling lactate in the liver
  3. Oxidative phosphorylation in the mitochondria
  4. The fast component of aerobic glycolysis in the cytosol

Explanation

Efforts of about 6 seconds or less are dominated by the ATP-PCr (phosphagen) system, which regenerates ATP from stored creatine phosphate faster than any other pathway. Glycolysis and oxidative phosphorylation contribute later because they require more enzymatic steps and, for oxidation, oxygen delivery.

Question 42Exercise Physiology and Energy Systems

Which substrate yields the greatest ATP per molecule when fully oxidized aerobically?

  1. Ketone bodies
  2. Muscle glycogen
  3. Free fatty acids Correct answer.
  4. Blood glucose

Explanation

Fatty acids are highly reduced and yield far more ATP per molecule than carbohydrate because they enter beta-oxidation and produce abundant acetyl-CoA and NADH/FADH2. Their high yield per molecule comes at the cost of a slower rate of ATP production.

Question 43Exercise Physiology and Energy Systems

The lactate threshold is best described as the exercise intensity at which:

  1. muscle pH falls below 6.0 and contraction ceases
  2. blood lactate begins to accumulate faster than it can be cleared Correct answer.
  3. creatine phosphate stores are fully depleted
  4. oxygen consumption plateaus despite increasing workload

Explanation

The lactate threshold marks the intensity where lactate appearance in blood exceeds clearance, producing a sustained rise in concentration. It is a key predictor of endurance performance because it reflects the balance between glycolytic flux and oxidative clearance.

Question 44Exercise Physiology and Energy Systems

Which muscle fiber type is characterized by high oxidative capacity, many mitochondria, and resistance to fatigue?

  1. Type I slow-twitch fibers Correct answer.
  2. Type IIx fast-twitch fibers
  3. Type IIa fast-twitch fibers
  4. Type IIb glycolytic fibers

Explanation

Type I fibers have dense capillarization, abundant mitochondria, and high myoglobin, giving them strong aerobic capacity and fatigue resistance. They are recruited first for low-intensity, sustained activity.

Question 45Exercise Physiology and Energy Systems

Which hormone is primarily responsible for increasing glucose uptake into skeletal muscle at rest after a meal?

  1. Insulin Correct answer.
  2. Cortisol
  3. Glucagon
  4. Epinephrine

Explanation

Insulin promotes translocation of GLUT4 transporters to the muscle membrane, increasing glucose uptake. At rest after a meal, insulin is the main hormonal driver of this response. During exercise, muscle contraction can also increase glucose uptake through insulin-independent GLUT4 translocation.

Question 46Exercise Physiology and Energy Systems

The primary role of creatine phosphate during short, intense exercise is to:

  1. buffer hydrogen ions produced by glycolysis
  2. convert pyruvate into acetyl-CoA
  3. regenerate ATP by transferring a phosphate to ADP Correct answer.
  4. transport fatty acids into the mitochondria

Explanation

Creatine kinase catalyzes the transfer of a phosphate group from creatine phosphate to ADP, rapidly regenerating ATP. This reaction supports maximal power output for the first several seconds of intense effort.

Question 47Exercise Physiology and Energy Systems

During prolonged submaximal exercise, which fuel source becomes increasingly important as glycogen stores decline?

  1. Plasma free fatty acids Correct answer.
  2. Muscle creatine phosphate
  3. Intramuscular ATP stores
  4. Blood lactate

Explanation

As glycogen depletes and hormonal signals favor lipolysis, plasma free fatty acids become an increasingly dominant fuel for oxidative metabolism. This shift spares carbohydrate but reduces the rate of ATP production at high intensities.

Question 48Exercise Physiology and Energy Systems

Which of the following best describes the oxygen deficit incurred at the start of exercise?

  1. The oxygen stored in myoglobin at rest
  2. The lag between oxygen demand and oxygen delivery at exercise onset Correct answer.
  3. The excess oxygen consumed after exercise ends
  4. The oxygen consumed above baseline during a warm-up

Explanation

At exercise onset, oxidative ATP production lags behind demand, creating an oxygen deficit that is covered by anaerobic sources. The deficit is later repaid in part by elevated post-exercise oxygen consumption.

Question 49Exercise Physiology and Energy Systems

A runner performs 30 seconds of all-out cycling. Which metabolic pathway contributes most to ATP resynthesis during this effort?

  1. Beta-oxidation of fatty acids
  2. Fast glycolysis Correct answer.
  3. Oxidative phosphorylation
  4. The ATP-PCr system

Explanation

At 30 seconds, fast glycolysis (anaerobic glycolysis) is the dominant contributor because phosphagen stores are largely depleted and oxidative metabolism cannot yet meet demand. This pathway produces ATP rapidly but generates lactate and hydrogen ions.

Question 50Exercise Physiology and Energy Systems

A strength athlete wants to maximize phosphagen system contribution during training. Which rest interval best supports this goal?

  1. 45 to 60 seconds between sets
  2. 3 to 5 minutes between sets Correct answer.
  3. 10 minutes between sets
  4. 15 to 20 seconds between sets

Explanation

Phosphagen resynthesis is largely complete within 3 to 5 minutes, so longer rest intervals preserve creatine phosphate availability and allow high power output across sets. Shorter rests shift reliance toward glycolysis and reduce power.