CSCS CSCS: Bioenergetics of Exercise & Training 4

Question 1

Which of the following training adaptations most directly increases the lactate threshold as a percentage of VO2max?

Accepted Answer

Greater mitochondrial density and oxidative enzyme activity in slow-twitch fibers

Answer

Greater mitochondrial density and oxidative capacity allow muscle to clear lactate more efficiently and rely less on glycolysis at a given intensity.

Question 2

Approximately how many ATP molecules are produced per mole of palmitate (a 16-carbon fatty acid) during complete beta-oxidation and Krebs cycle oxidation?

Accepted Answer

129

Answer

Complete oxidation of palmitate yields approximately 129 ATP through combined beta-oxidation, Krebs cycle, and oxidative phosphorylation.

Question 3

What is the primary regulatory role of AMP in skeletal muscle bioenergetics?

Accepted Answer

AMP stimulates phosphofructokinase and AMP kinase, signaling low energy status

Answer

Rising AMP signals energy deficit, activating PFK (glycolysis) and AMPK (promoting fat oxidation and mitochondrial biogenesis) to restore ATP.

Question 4

Which energy system is MOST responsible for ATP production during a 400-meter race run at maximal effort (~45–60 seconds)?

Accepted Answer

Glycolytic system predominantly, with phosphagen contribution early

Answer

The 400m race relies primarily on anaerobic glycolysis for most of its duration, with the phosphagen system dominant in the first seconds and some aerobic contribution.

Question 5

Ketone bodies (acetoacetate and beta-hydroxybutyrate) become a significant fuel source primarily during:

Accepted Answer

Prolonged low-carbohydrate states such as fasting or very-low-carb diets

Answer

Ketone bodies are produced by the liver from fatty acids during prolonged carbohydrate restriction or fasting and serve as an alternative fuel for brain and muscle.

Certified Strength and Conditioning Specialist Practice Test

Certified Strength and Conditioning Specialist Practice Test

CSCS CSCS: Bioenergetics of Exercise & Training 4