BHK Sports Nutrition 2 — Questions and Answers
Question 1: Which vitamin is essential for calcium absorption in the gut and is often deficient in indoor athletes?
- Vitamin K
- Vitamin C
- Vitamin D (Correct answer)
- Vitamin B12
Correct answer: Vitamin D
Vitamin D is synthesized from sunlight exposure and is critical for intestinal calcium absorption; indoor athletes often have insufficient levels.
Question 2: Relative Energy Deficiency in Sport (RED-S) is most directly caused by:
- Excessive protein intake
- Low energy availability due to inadequate caloric intake relative to exercise energy expenditure (Correct answer)
- Overhydration during training
- High carbohydrate diet
Correct answer: Low energy availability due to inadequate caloric intake relative to exercise energy expenditure
RED-S occurs when dietary energy intake is insufficient to cover both resting metabolic needs and exercise costs, disrupting multiple physiological systems.
Question 3: The primary role of beta-alanine supplementation in athletes is to:
- Increase muscle glycogen storage
- Buffer intramuscular hydrogen ions by increasing carnosine levels (Correct answer)
- Enhance fat oxidation during exercise
- Increase testosterone production
Correct answer: Buffer intramuscular hydrogen ions by increasing carnosine levels
Beta-alanine raises intramuscular carnosine, which acts as a pH buffer, delaying acidosis and fatigue during high-intensity exercise lasting 1–4 minutes.
Question 4: Which macronutrient has the highest thermic effect of food (TEF), meaning it requires the most energy to digest?
- Carbohydrate
- Fat
- Protein (Correct answer)
- Alcohol
Correct answer: Protein
Protein has a TEF of approximately 20–30%, meaning 20–30% of its calories are used in its own digestion, compared to 5–10% for carbohydrate and 0–3% for fat.
Question 5: Post-exercise carbohydrate-protein co-ingestion is recommended primarily because:
- It prevents ketosis
- Protein alone is more effective at restoring glycogen
- Protein amplifies insulin response and enhances glycogen resynthesis alongside carbohydrate (Correct answer)
- Fat storage is reduced when both are consumed
Correct answer: Protein amplifies insulin response and enhances glycogen resynthesis alongside carbohydrate
Adding protein to post-exercise carbohydrate intake enhances insulin secretion and provides amino acids for tissue repair while supporting glycogen replenishment.
Question 6: Caffeine improves endurance performance primarily through which mechanism?
- Directly increasing muscle glycogen synthesis
- Antagonizing adenosine receptors in the brain, reducing perception of effort and fatigue (Correct answer)
- Increasing fat storage mobilization only
- Stimulating insulin secretion
Correct answer: Antagonizing adenosine receptors in the brain, reducing perception of effort and fatigue
Caffeine blocks adenosine receptors in the central nervous system, reducing perceived exertion and delaying fatigue during prolonged exercise.
BHK Sports Nutrition 2
Which vitamin is essential for calcium absorption in the gut and is often deficient in indoor athletes?