BHK Exercise Physiology 2 — Questions and Answers
Question 1: The Fick equation states that VO2 = cardiac output × which other variable?
- Heart rate
- Arteriovenous oxygen difference (a-vO2 diff) (Correct answer)
- Tidal volume
- Respiratory rate
Correct answer: Arteriovenous oxygen difference (a-vO2 diff)
The Fick principle expresses oxygen consumption as the product of cardiac output and the a-vO2 difference across the tissues.
Question 2: Which adaptation is NOT typically associated with chronic endurance training?
- Increased resting stroke volume
- Cardiac hypertrophy (eccentric)
- Increased fast-twitch fiber proportion (Correct answer)
- Lower resting heart rate
Correct answer: Increased fast-twitch fiber proportion
Endurance training does not increase the proportion of fast-twitch fibers; it may convert Type IIx to Type IIa but not increase Type II overall.
Question 3: During prolonged moderate-intensity exercise, which substrate becomes increasingly important as glycogen stores decline?
- Protein
- Fat (free fatty acids) (Correct answer)
- Creatine phosphate
- Lactate from red blood cells
Correct answer: Fat (free fatty acids)
As glycogen depletes during prolonged exercise, fat oxidation (free fatty acids) progressively contributes more to energy production.
Question 4: What is the primary cause of the increase in core body temperature during exercise?
- Decreased sweating rate
- Metabolic heat production by contracting muscles (Correct answer)
- Increased basal metabolic rate only
- Reduced blood flow to the skin
Correct answer: Metabolic heat production by contracting muscles
Approximately 75–80% of the energy released during muscle contraction is in the form of heat, raising core temperature.
Question 5: Which component of energy expenditure is the largest contributor to total daily energy expenditure in sedentary individuals?
- Thermic effect of food
- Exercise activity thermogenesis
- Resting metabolic rate (Correct answer)
- Non-exercise activity thermogenesis
Correct answer: Resting metabolic rate
Resting metabolic rate (RMR) accounts for approximately 60–75% of total daily energy expenditure in sedentary people.
Question 6: Excess post-exercise oxygen consumption (EPOC) is primarily driven by which process?
- Replenishment of ATP-PCr stores and clearance of metabolic by-products (Correct answer)
- Increased glycolysis during recovery
- Reduced ventilation post-exercise
- Depletion of intramuscular triglycerides
Correct answer: Replenishment of ATP-PCr stores and clearance of metabolic by-products
EPOC reflects elevated oxygen use after exercise to restore phosphocreatine, clear lactate, re-oxygenate myoglobin, and normalize body temperature.
BHK Exercise Physiology 2
The Fick equation states that VO2 = cardiac output × which other variable?