CSCS CSCS: Bioenergetics of Exercise & Training 5

Question 1

Which of the following accurately describes the fate of lactate during low-to-moderate intensity exercise in trained athletes?

Accepted Answer

Lactate is oxidized directly as a fuel by heart, slow-twitch fibers, and liver

Answer

Trained muscles and the heart can oxidize lactate directly via the intracellular lactate shuttle, using it as an aerobic substrate.

Question 2

How does carnitine facilitate fat metabolism in skeletal muscle?

Accepted Answer

Carnitine transports activated fatty acids (acyl-CoA) across the inner mitochondrial membrane

Answer

Carnitine acyltransferase enzymes use carnitine to shuttle long-chain acyl-CoA molecules across the inner mitochondrial membrane for beta-oxidation.

Question 3

Which of the following best explains the 'slow component' of VO2 kinetics observed during heavy exercise?

Accepted Answer

Progressive recruitment of less efficient fast-twitch fibers as fatigue sets in

Answer

The VO2 slow component arises from progressive recruitment of less efficient type II fibers, increasing the oxygen cost of maintaining a given power output.

Question 4

Training-induced mitochondrial biogenesis is primarily regulated by which signaling molecule?

Accepted Answer

PGC-1α (peroxisome proliferator-activated receptor gamma coactivator 1-alpha)

Answer

PGC-1α is the master regulator of mitochondrial biogenesis, activated by endurance training signals such as AMPK and calcium-calmodulin kinase.

Question 5

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?

Accepted Answer

Stored ATP in the muscle cell

Answer

The muscle cell has a small but immediately available pool of free ATP that is the very first energy source used at exercise onset.

Certified Strength and Conditioning Specialist Practice Test

Certified Strength and Conditioning Specialist Practice Test

CSCS CSCS: Bioenergetics of Exercise & Training 5