CSN Sports & Exercise Physiology 2

Question 1

A sprinter performs a maximal 6-second effort. Which energy system supplies the majority of ATP?

Accepted Answer

Phosphocreatine (ATP-PCr) system

Answer

The ATP-PCr system dominates maximal efforts lasting roughly 0-10 seconds.

Question 2

Which enzyme is considered the rate-limiting step of glycolysis?

Accepted Answer

Phosphofructokinase (PFK)

Answer

PFK is the key regulatory enzyme of glycolysis and is stimulated by rising ADP and AMP.

Question 3

During a 400 m run lasting about 50 seconds, which system contributes most to ATP production?

Accepted Answer

Anaerobic glycolysis

Answer

Efforts of roughly 30 seconds to 2 minutes rely mostly on fast (anaerobic) glycolysis.

Question 4

The 'crossover concept' describes what shift as exercise intensity increases?

Accepted Answer

From fat to carbohydrate as the main fuel

Answer

As intensity rises, carbohydrate's share of energy expenditure rises and fat's share falls.

Question 5

Excess post-exercise oxygen consumption (EPOC) is partly used to do which of the following?

Accepted Answer

Resynthesize phosphocreatine and restore oxygen stores

Answer

EPOC supports PCr resynthesis, oxygen restoration in myoglobin and blood, and elevated temperature and hormone effects.

CSN - Certified Sports Nutritionist Practice Test