CSSD Macronutrient Timing 5 — Questions and Answers
Question 1: A female soccer player has a 7 PM game and her last substantial meal was at noon. Which pre-game snack, consumed at 5:30 PM, is most appropriate?
- Peanut butter sandwich with a glass of whole milk
- A banana, sports drink, and a small amount of pretzels (Correct answer)
- A high-fiber energy bar and sparkling water
- A large mixed salad with grilled chicken and olive oil dressing
Correct answer: A banana, sports drink, and a small amount of pretzels
A snack 90 minutes before competition should be moderate in rapidly digestible carbohydrates, low in fat and fiber, and well-tolerated—a banana, sports drink, and pretzels meet these criteria.
Question 2: In resistance-trained older adults (50+ years), how does the leucine threshold for maximally stimulating MPS compare to younger athletes?
- Lower; older adults need less leucine due to metabolic efficiency
- The same; age does not affect leucine sensitivity
- Higher; older adults exhibit anabolic resistance requiring more leucine or protein (Correct answer)
- Lower; older adults absorb amino acids faster
Correct answer: Higher; older adults exhibit anabolic resistance requiring more leucine or protein
Aging is associated with anabolic resistance, meaning older adults require more total protein (and leucine) per meal to achieve the same MPS response as younger individuals.
Question 3: Which carbohydrate form is most evidence-supported for intra-exercise use when solid food consumption is impractical?
- Energy chews with 25g carbohydrate per serving
- Sports gels delivering 20–25g of mixed carbohydrates per sachet with water (Correct answer)
- Protein bars with embedded carbohydrates
- Dried fruit alone providing 30g carbohydrate
Correct answer: Sports gels delivering 20–25g of mixed carbohydrates per sachet with water
Sports gels providing 20–25g of carbohydrate (typically glucose + fructose blend) consumed with water are the most studied, portable, and tolerated intra-exercise carbohydrate form.
Question 4: A CSSD working with a marathon runner recommends 'carbohydrate periodization.' Which statement best describes this approach?
- Eating only carbohydrates on hard training days and avoiding them on rest days
- Strategically manipulating carbohydrate availability across training sessions to promote both metabolic adaptation and fueled performance (Correct answer)
- Consuming the same carbohydrate amount daily regardless of training load
- Eliminating carbohydrates entirely during base-building phases
Correct answer: Strategically manipulating carbohydrate availability across training sessions to promote both metabolic adaptation and fueled performance
Carbohydrate periodization intentionally varies carbohydrate intake around training to enhance fat oxidation adaptations on low-carb sessions while fully fueling key performance sessions.
Question 5: What is the primary mechanism by which insulin facilitates post-exercise muscle glycogen resynthesis?
- Directly phosphorylating glycogen synthase to activate it
- Stimulating GLUT4 translocation to the muscle membrane to increase glucose uptake (Correct answer)
- Inhibiting glucagon release from the pancreas
- Increasing hepatic glucose production to supply muscle
Correct answer: Stimulating GLUT4 translocation to the muscle membrane to increase glucose uptake
Insulin promotes GLUT4 transporter translocation to the sarcolemma, dramatically increasing muscle glucose uptake and subsequent glycogen synthesis after exercise.
Question 6: A basketball player performs a 2-hour practice and loses 2 kg of body weight through sweat. To optimize recovery before the next day's game, which combination strategy is most appropriate?
- 1.5L fluid, 80g carbohydrate, and 20g protein within 2 hours post-practice (Correct answer)
- Only water replacement (1.5L) within the first hour
- High-fat, high-protein meal 4 hours post-practice with minimal fluid
- Sports drink ad libitum with no specific food timing
Correct answer: 1.5L fluid, 80g carbohydrate, and 20g protein within 2 hours post-practice
Optimal recovery combines rehydration (1.5× fluid loss), carbohydrate for glycogen resynthesis (~1–1.2g/kg/hr), and protein (~20–40g) for MPS—targeting these within 2 hours post-practice.
Question 7: Which scenario represents the most critical application of intra-exercise protein co-ingestion with carbohydrates?
- A 45-minute high-intensity interval session
- A 30-minute swim practice
- An ultramarathon exceeding 4–5 hours of continuous exercise (Correct answer)
- A 60-minute recreational cycling ride
Correct answer: An ultramarathon exceeding 4–5 hours of continuous exercise
During ultra-endurance events exceeding 4–5 hours, protein co-ingestion with carbohydrates can help spare muscle protein oxidation and reduce post-exercise muscle damage markers.
CSSD Macronutrient Timing 5
A female soccer player has a 7 PM game and her last substantial meal was at noon.
Which pre-game snack, consumed at 5:30 PM, is most appropriate?