CSCS: Bioenergetics of Exercise & Training Flashcards
7 cards from real CSCS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 CSCS: Bioenergetics of Exercise & Training flashcards as text
Which of the following accurately describes the fate of lactate during low-to-moderate intensity exercise in trained athletes?
Answer: Lactate is oxidized directly as a fuel by heart, slow-twitch fibers, and liver
Trained muscles and the heart can oxidize lactate directly via the intracellular lactate shuttle, using it as an aerobic substrate.
How does carnitine facilitate fat metabolism in skeletal muscle?
Answer: Carnitine transports activated fatty acids (acyl-CoA) across the inner mitochondrial membrane
Carnitine acyltransferase enzymes use carnitine to shuttle long-chain acyl-CoA molecules across the inner mitochondrial membrane for beta-oxidation.
Which of the following best explains the 'slow component' of VO2 kinetics observed during heavy exercise?
Answer: Progressive recruitment of less efficient fast-twitch fibers as fatigue sets in
The VO2 slow component arises from progressive recruitment of less efficient type II fibers, increasing the oxygen cost of maintaining a given power output.
Training-induced mitochondrial biogenesis is primarily regulated by which signaling molecule?
Answer: PGC-1α (peroxisome proliferator-activated receptor gamma coactivator 1-alpha)
PGC-1α is the master regulator of mitochondrial biogenesis, activated by endurance training signals such as AMPK and calcium-calmodulin kinase.
During the transition from rest to moderate-intensity exercise, what is the PRIMARY source of ATP during the first 1–2 seconds before other systems ramp up?
Answer: Stored ATP in the muscle cell
The muscle cell has a small but immediately available pool of free ATP that is the very first energy source used at exercise onset.
Which training intervention is MOST effective for maximally increasing muscle glycolytic enzyme (e.g., PFK, LDH) activity?
Answer: High-intensity interval training (HIIT) or sprint training
High-intensity interval and sprint training create the greatest upregulation of glycolytic enzymes due to repeated demand on anaerobic glycolysis.
An athlete's RER value measured at rest is 0.78. This indicates that approximately what percentage of energy is coming from fat?
Answer: 67%
An RER of 0.78 corresponds to approximately 67% fat and 33% carbohydrate contribution based on non-protein RER tables.