CSSD Exercise Physiology & Energy Metabolism 4

Question 1

What is the approximate ATP yield from the complete oxidation of one mole of palmitate (16-carbon saturated fatty acid)?

Accepted Answer

129 ATP

Answer

Palmitate oxidation yields approximately 129 ATP through combined beta-oxidation (producing NADH and FADH2) and subsequent oxidative phosphorylation of resulting acetyl-CoA in the TCA cycle.

Question 2

An athlete complains of 'hitting the wall' at mile 20 of a marathon. This phenomenon is primarily attributed to:

Accepted Answer

Near-depletion of liver and muscle glycogen stores

Answer

The 'wall' corresponds to glycogen depletion forcing greater reliance on fat oxidation, which cannot sustain race pace, resulting in a dramatic reduction in running speed.

Question 3

Which statement BEST describes muscle fiber recruitment during progressive increases in exercise intensity?

Accepted Answer

Type I fibers are recruited first, with Type IIa and IIx added as intensity increases (size principle)

Answer

Henneman's size principle dictates that smaller, fatigue-resistant Type I motor units are recruited first, with larger Type II units added as force demands increase.

Question 4

During prolonged exercise in the heat, which combination of stressors MOST compromises muscle glycogen sparing?

Accepted Answer

Hyperthermia and dehydration

Answer

Hyperthermia accelerates glycogenolysis and dehydration increases circulating catecholamines and reduces hepatic glucose output, together accelerating glycogen depletion.

Question 5

What is the primary nutritional strategy to maximize muscle glycogen supercompensation before an endurance event?

Accepted Answer

3–4 days of high carbohydrate intake (8–12 g/kg/day) combined with exercise taper

Answer

Current evidence supports 3–4 days of high carbohydrate intake (8–12 g/kg/day) paired with exercise tapering to maximize glycogen stores prior to competition.

(CSSD) Board Certified Specialist in Sports Dietetics Practice Test

(CSSD) Board Certified Specialist in Sports Dietetics Practice Test

CSSD Exercise Physiology & Energy Metabolism 4