CSSD Exercise Physiology & Energy Metabolism 5

Question 1

Which metabolic adaptation MOST distinguishes skeletal muscle of a highly trained endurance athlete compared to an untrained individual?

Accepted Answer

Greater intramuscular triglyceride (IMTG) stores and enhanced lipid oxidation capacity

Answer

Endurance training increases IMTG content and upregulates lipid oxidative enzymes, enabling the athlete to oxidize fat at higher absolute workloads and spare glycogen.

Question 2

Excess post-exercise oxygen consumption (EPOC) after high-intensity exercise is PRIMARILY driven by:

Accepted Answer

Resynthesis of phosphocreatine, lactate clearance, elevated temperature, and hormonal effects

Answer

EPOC results from multiple oxygen-consuming processes: PCr resynthesis, lactate-to-glycogen conversion, elevated core temperature, and catecholamine-driven elevation of metabolic rate.

Question 3

During altitude acclimatization, which metabolic shift occurs that affects carbohydrate and fat utilization?

Accepted Answer

Initial increased reliance on carbohydrate due to hypoxia-induced AMPK activation and PDH upregulation

Answer

Hypoxia activates AMPK and pyruvate dehydrogenase, shifting substrate preference toward carbohydrate oxidation because fat oxidation requires more oxygen per ATP produced.

Question 4

Which concept explains why athletes performing concurrent training (strength + endurance) may see blunted strength gains compared to strength training alone?

Accepted Answer

AMPK-mTOR interference, where AMPK activated by endurance work suppresses mTORC1-driven hypertrophy signaling

Answer

Endurance exercise activates AMPK, which can phosphorylate and inhibit mTORC1, the primary anabolic signaling hub for muscle protein synthesis and hypertrophy.

Question 5

A female soccer player in a prolonged energy deficit shows blunted resting metabolic rate (RMR). This adaptation is MOST consistent with:

Accepted Answer

Metabolic adaptation (adaptive thermogenesis) reducing RMR below predicted values

Answer

Chronic low energy availability triggers adaptive thermogenesis, suppressing RMR below predictions based on lean mass, consistent with Relative Energy Deficiency in Sport (RED-S).

(CSSD) Board Certified Specialist in Sports Dietetics Practice Test

(CSSD) Board Certified Specialist in Sports Dietetics Practice Test

CSSD Exercise Physiology & Energy Metabolism 5