ACSM Exercise Science 4 — Questions and Answers
Question 1: Which hormone is primarily responsible for mobilizing free fatty acids from adipose tissue during prolonged aerobic exercise?
- Insulin
- Cortisol
- Epinephrine (Correct answer)
- Aldosterone
Correct answer: Epinephrine
Epinephrine activates hormone-sensitive lipase in adipose tissue, stimulating lipolysis and releasing free fatty acids into the bloodstream during exercise.
Question 2: What is the ventilatory threshold and how does it relate to exercise intensity?
- The point at which breathing stops temporarily during exercise
- The intensity where ventilation increases disproportionately to VO2 due to CO2 buffering (Correct answer)
- The minimum tidal volume required for gas exchange
- The respiratory rate at maximal exertion
Correct answer: The intensity where ventilation increases disproportionately to VO2 due to CO2 buffering
The ventilatory threshold represents the exercise intensity at which CO2 production from bicarbonate buffering of lactate drives a nonlinear increase in ventilation.
Question 3: Which of the following adaptations occurs in skeletal muscle mitochondria with long-term aerobic training?
- Decreased mitochondrial enzyme activity
- Reduced number of mitochondria
- Increased mitochondrial density and oxidative enzyme activity (Correct answer)
- Shift from oxidative to glycolytic metabolism
Correct answer: Increased mitochondrial density and oxidative enzyme activity
Chronic aerobic training increases mitochondrial biogenesis, elevating both the number and size of mitochondria and enhancing oxidative enzyme activity.
Question 4: What is the SAID principle in exercise science?
- Specific Adaptations to Imposed Demands (Correct answer)
- Systematic Approach to Integrated Development
- Sequential Advancement in Intensity Distribution
- Standardized Assessment of Individual Differences
Correct answer: Specific Adaptations to Imposed Demands
SAID stands for Specific Adaptations to Imposed Demands, meaning the body adapts specifically to the type of stress placed upon it.
Question 5: During submaximal exercise in a hot environment, which cardiovascular adjustment helps maintain core temperature?
- Vasoconstriction in the skin
- Increased blood flow to the kidneys
- Cutaneous vasodilation redirecting blood to the skin (Correct answer)
- Reduced cardiac output
Correct answer: Cutaneous vasodilation redirecting blood to the skin
Cutaneous vasodilation shunts blood to the skin to facilitate heat dissipation via radiation and convection, which competes with muscle blood flow demands.
Question 6: What is the effect of altitude on VO2max and the primary physiological cause?
- VO2max increases due to polycythemia
- VO2max is unaffected at moderate altitude
- VO2max decreases due to reduced arterial oxygen content (Correct answer)
- VO2max decreases due to increased lung diffusion capacity
Correct answer: VO2max decreases due to reduced arterial oxygen content
At altitude, reduced partial pressure of oxygen lowers arterial oxygen saturation (SaO2), decreasing oxygen delivery to muscles and reducing VO2max.
Question 7: Which of the following describes the principle of reversibility in exercise training?
- Training benefits are permanent once achieved
- Detraining leads to loss of physiological adaptations gained through exercise (Correct answer)
- Reversing training order maximizes gains
- Adaptations occur in the opposite direction of training stress
Correct answer: Detraining leads to loss of physiological adaptations gained through exercise
Reversibility (detraining) occurs when training ceases, causing progressive loss of cardiovascular and muscular adaptations within weeks.
ACSM Exercise Science 4
Which hormone is primarily responsible for mobilizing free fatty acids from adipose tissue during prolonged aerobic exercise?