Exercise Physiology Flashcards
7 cards from real ACSM practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Exercise Physiology flashcards as text
During prolonged exercise lasting 2+ hours, hypoglycemia can impair performance primarily because:
Answer: The central nervous system relies heavily on glucose as fuel
The brain depends almost exclusively on glucose; hypoglycemia impairs CNS function, leading to fatigue, confusion, and cessation of exercise.
Which of the following best describes the effect of dehydration equivalent to 2% of body weight on aerobic exercise performance?
Answer: Up to 20% decrease in aerobic performance capacity
A 2% body weight deficit from dehydration can reduce aerobic performance by approximately 10–20% due to decreased plasma volume and cardiac output.
Muscle glycogen resynthesis after prolonged exercise is maximized when carbohydrate is consumed:
Answer: Within 30–60 minutes after exercise ends
Glycogen synthase activity and muscle insulin sensitivity are highest immediately post-exercise, making early carbohydrate intake critical for rapid resynthesis.
Which phenomenon explains why trained endurance athletes oxidize more fat and less carbohydrate at a given absolute submaximal workload compared to untrained individuals?
Answer: Training-induced increase in mitochondrial density and fat oxidation enzymes
Aerobic training increases mitochondrial density and enzymes such as citrate synthase, enabling greater fat oxidation at the same absolute workload.
What is the primary mechanism by which beta-blockers limit exercise performance?
Answer: They blunt the catecholamine-mediated increase in heart rate, limiting maximal cardiac output
Beta-blockers block beta-1 adrenergic receptors on the heart, preventing the catecholamine-driven heart rate increase and thus limiting maximal cardiac output.
The crossover concept in exercise metabolism states that as exercise intensity increases:
Answer: Carbohydrate oxidation progressively increases while fat oxidation decreases
The crossover concept describes the shift from fat-dominant to carbohydrate-dominant energy supply as exercise intensity increases toward VO2max.
Which of the following is a primary long-term skeletal muscle adaptation to high-intensity interval training (HIIT)?
Answer: Increased mitochondrial biogenesis and oxidative enzyme activity
HIIT stimulates mitochondrial biogenesis (via PGC-1α activation) and upregulates oxidative enzymes similar to continuous endurance training.