NSCA-CPT Exercise Physiology 2 — Questions and Answers
Question 1: Which energy system is the PRIMARY source for a 400-meter sprint?
- Phosphagen system
- Glycolytic system (Correct answer)
- Oxidative system
- Creatine phosphate only
Correct answer: Glycolytic system
The 400-meter sprint (approximately 45–60 seconds) relies primarily on the glycolytic (anaerobic lactic) system.
Question 2: During prolonged aerobic exercise, which fuel source becomes increasingly important as glycogen stores deplete?
- Creatine phosphate
- Free fatty acids (Correct answer)
- ATP from phosphagen
- Dietary carbohydrates consumed pre-exercise only
Correct answer: Free fatty acids
As muscle glycogen decreases during prolonged exercise, free fatty acid oxidation progressively contributes more to energy production.
Question 3: What is the approximate oxygen uptake at rest (1 MET) for the average adult?
- 1.5 ml/kg/min
- 3.5 ml/kg/min (Correct answer)
- 7.0 ml/kg/min
- 10.0 ml/kg/min
Correct answer: 3.5 ml/kg/min
One MET equals approximately 3.5 ml/kg/min of oxygen consumption, the standard resting metabolic rate.
Question 4: Which cardiac parameter is defined as the volume of blood ejected per heartbeat?
- Cardiac output
- Stroke volume (Correct answer)
- Heart rate
- End-diastolic volume
Correct answer: Stroke volume
Stroke volume is the amount of blood pumped by the left ventricle with each contraction.
Question 5: The Fick equation states that VO2 = cardiac output × which variable?
- Heart rate
- Stroke volume
- Arteriovenous oxygen difference (Correct answer)
- Tidal volume
Correct answer: Arteriovenous oxygen difference
The Fick principle expresses VO2 as the product of cardiac output and the a-vO2 difference (oxygen extracted by tissues).
Question 6: During maximal aerobic exercise, which factor is most responsible for limiting VO2max in healthy, untrained individuals?
- Pulmonary diffusion capacity
- Maximal cardiac output (Correct answer)
- Mitochondrial enzyme activity
- Blood lactate threshold
Correct answer: Maximal cardiac output
In healthy untrained individuals, maximal cardiac output (heart rate × stroke volume) is the primary limiting factor for VO2max.
Question 7: What physiological change explains why trained endurance athletes have lower resting heart rates than untrained individuals?
- Decreased stroke volume
- Increased stroke volume (cardiac hypertrophy) (Correct answer)
- Reduced blood viscosity
- Lower blood pressure
Correct answer: Increased stroke volume (cardiac hypertrophy)
Endurance training causes cardiac hypertrophy and increased stroke volume, allowing the heart to maintain cardiac output at a lower heart rate.
NSCA-CPT Exercise Physiology 2
Which energy system is the PRIMARY source for a 400-meter sprint?