CNC CNC Sports Nutrition & Performance 2 — Questions and Answers
Question 1: What is the recommended protein intake range for strength/power athletes seeking to maximize muscle protein synthesis and hypertrophy?
- 0.8 g/kg/day
- 1.0–1.2 g/kg/day
- 1.6–2.2 g/kg/day (Correct answer)
- 3.5–4.0 g/kg/day
Correct answer: 1.6–2.2 g/kg/day
Current evidence supports 1.6–2.2 g/kg/day as the optimal range for maximizing muscle protein synthesis in resistance-trained individuals, with no added benefit beyond this range.
Question 2: Creatine monohydrate supplementation primarily enhances performance in which type of exercise?
- Long-duration aerobic events (marathon)
- High-intensity, short-duration efforts (sprints, lifting) (Correct answer)
- Flexibility and mobility training
- Low-intensity steady-state cardio
Correct answer: High-intensity, short-duration efforts (sprints, lifting)
Creatine increases phosphocreatine stores in muscle, enhancing ATP resynthesis during repeated bouts of high-intensity, short-duration exercise like sprinting and resistance training.
Question 3: Relative Energy Deficiency in Sport (RED-S) is most likely to develop when:
- An athlete consumes too much protein relative to carbohydrate
- Energy intake is chronically insufficient to support both physiological function and exercise demands (Correct answer)
- An athlete trains exclusively at high altitude
- Carbohydrate intake exceeds 60% of total calories
Correct answer: Energy intake is chronically insufficient to support both physiological function and exercise demands
RED-S occurs when low energy availability — energy intake minus exercise energy expenditure — is insufficient to support normal physiological processes, impairing health and performance across multiple organ systems.
Question 4: Which amino acid is conditionally essential during high-stress states such as intense training and is a primary fuel source for intestinal cells?
- Leucine
- Glutamine (Correct answer)
- Valine
- Lysine
Correct answer: Glutamine
Glutamine becomes conditionally essential under metabolic stress; it fuels enterocytes and immune cells and may support gut integrity and immune function in heavily training athletes.
Question 5: Beta-alanine supplementation improves performance primarily by:
- Increasing ATP production via the phosphagen system
- Elevating muscle carnosine levels, buffering hydrogen ions during high-intensity exercise (Correct answer)
- Stimulating growth hormone release
- Enhancing fat oxidation during aerobic exercise
Correct answer: Elevating muscle carnosine levels, buffering hydrogen ions during high-intensity exercise
Beta-alanine is a precursor to carnosine; elevated intramuscular carnosine acts as an intracellular pH buffer, delaying fatigue during high-intensity exercise lasting 1–4 minutes.
Question 6: During ultra-endurance events lasting more than 3 hours, an athlete's exogenous carbohydrate oxidation can be maximized by combining which two carbohydrate sources?
- Fructose and galactose
- Glucose and fructose (Correct answer)
- Sucrose and lactose
- Maltodextrin only
Correct answer: Glucose and fructose
Glucose and fructose use different intestinal transporters (SGLT-1 and GLUT-5, respectively), allowing combined oxidation rates up to 90 g/hour compared to ~60 g/hour with glucose alone.
CNC CNC Sports Nutrition & Performance 2
What is the recommended protein intake range for strength/power athletes seeking to maximize muscle protein synthesis and hypertrophy?