NSCA CSCS Exercise Science Principles 3 — Questions and Answers
Question 1: Cardiac hypertrophy induced by endurance training is primarily characterized by:
- Increased left ventricular wall thickness with reduced chamber volume
- Increased left ventricular chamber volume with proportional wall thickness (eccentric hypertrophy) (Correct answer)
- Decreased stroke volume and increased heart rate
- Right ventricular hypertrophy with left ventricular atrophy
Correct answer: Increased left ventricular chamber volume with proportional wall thickness (eccentric hypertrophy)
Chronic endurance training produces eccentric (volume-load) hypertrophy — an enlarged LV cavity with a proportionally larger stroke volume.
Question 2: Which hormone is primarily responsible for acute increases in blood glucose during high-intensity exercise?
- Insulin
- Glucagon
- Epinephrine (Correct answer)
- Cortisol
Correct answer: Epinephrine
Epinephrine (adrenaline) released from the adrenal medulla stimulates hepatic glycogenolysis to rapidly elevate blood glucose during intense exercise.
Question 3: The primary role of calcium (Ca²⁺) in muscle contraction is to:
- Provide energy for cross-bridge cycling via ATP hydrolysis
- Bind to troponin C, moving tropomyosin to expose actin binding sites (Correct answer)
- Directly activate myosin ATPase enzyme activity
- Stabilize the Z-disc structure during sarcomere shortening
Correct answer: Bind to troponin C, moving tropomyosin to expose actin binding sites
Ca²⁺ released from the sarcoplasmic reticulum binds troponin C, causing a conformational shift in tropomyosin that exposes myosin-binding sites on actin.
Question 4: The respiratory exchange ratio (RER) value of 0.70 indicates that the primary fuel source is:
- Carbohydrate
- Mixed fuels (fat and carbohydrate equally)
- Fat (Correct answer)
- Protein
Correct answer: Fat
An RER of 0.70 reflects complete fat oxidation (CO2 produced / O2 consumed = 0.70), consistent with lipid metabolism.
Question 5: Which principle explains why a heavier object requires greater muscular force to accelerate at the same rate as a lighter object?
- Newton's First Law (Law of Inertia)
- Newton's Second Law (F = ma) (Correct answer)
- Newton's Third Law (action-reaction)
- Bernoulli's principle
Correct answer: Newton's Second Law (F = ma)
Newton's Second Law (F = ma) states force equals mass times acceleration, so greater mass requires proportionally greater force for the same acceleration.
Question 6: During prolonged moderate-intensity exercise, which metabolic shift occurs after approximately 2 hours?
- Increased reliance on muscle glycogen with decreased fat oxidation
- Shift toward greater fat oxidation as glycogen stores deplete (Correct answer)
- Exclusive use of blood glucose without muscle glycogen involvement
- Protein becomes the sole fuel source replacing all carbohydrate
Correct answer: Shift toward greater fat oxidation as glycogen stores deplete
As muscle and liver glycogen deplete during prolonged exercise, fat oxidation (free fatty acid mobilization) increases to supply a greater proportion of ATP.
Question 7: The Golgi tendon organ (GTO) responds primarily to:
- Rapid changes in muscle length
- Muscle tension/force development (Correct answer)
- Joint position sense
- Muscle temperature changes
Correct answer: Muscle tension/force development
GTOs are tension-sensitive mechanoreceptors located at the muscle-tendon junction that fire in response to active force production by the muscle.
NSCA CSCS Exercise Science Principles 3
Cardiac hypertrophy induced by endurance training is primarily characterized by: