ACSM Nutrition 5 — Questions and Answers
Question 1: Which type of dietary fiber is MOST effective at lowering LDL cholesterol by binding bile acids in the gastrointestinal tract?
- Insoluble fiber (cellulose)
- Soluble fiber (beta-glucan, pectin) (Correct answer)
- Resistant starch
- Lignin
Correct answer: Soluble fiber (beta-glucan, pectin)
Soluble fibers like beta-glucan and pectin form viscous gels that bind bile acids, reducing their reabsorption and forcing the liver to convert more cholesterol into new bile acids.
Question 2: What is the primary nitrogen-excretion mechanism used to assess protein oxidation and nitrogen balance in nutrition research?
- Fecal nitrogen analysis
- Urinary urea nitrogen measurement (Correct answer)
- Respiratory quotient monitoring
- Plasma amino acid profiling
Correct answer: Urinary urea nitrogen measurement
Urinary urea nitrogen accounts for approximately 80–85% of total nitrogen excretion and is the standard method to calculate nitrogen balance (intake minus output).
Question 3: A marathon runner is 20 miles into a race and begins experiencing disorientation, muscle cramps, and nausea after consuming only plain water throughout. Which condition is MOST likely?
- Hypernatremia
- Hyponatremia (Correct answer)
- Hyperkalemia
- Dehydration-induced hypoglycemia
Correct answer: Hyponatremia
Hyponatremia (serum sodium <135 mEq/L) results from excessive plain water intake diluting sodium; it is a serious and potentially fatal condition in endurance athletes.
Question 4: Which amino acid is considered conditionally essential during periods of intense physiological stress, such as heavy training or trauma?
- Leucine
- Glutamine (Correct answer)
- Valine
- Lysine
Correct answer: Glutamine
Glutamine becomes conditionally essential under high physiological stress because endogenous synthesis cannot meet the increased demands of the immune system and rapidly dividing cells.
Question 5: According to ACSM, what is the minimum recommended daily fluid intake from beverages (excluding food moisture) for active adults in temperate climates?
- 1.0–1.5 L/day
- 1.5–2.0 L/day
- 2.0–3.0 L/day (Correct answer)
- 3.0–4.0 L/day
Correct answer: 2.0–3.0 L/day
ACSM and the Institute of Medicine recommend approximately 2.0–3.0 L/day from beverages for active adults, with additional intake to compensate for exercise-induced sweat losses.
Question 6: The respiratory quotient (RQ) of 0.70 during submaximal exercise indicates that the primary fuel source is:
- Carbohydrate
- Mixed carbohydrate and fat
- Fat (Correct answer)
- Protein
Correct answer: Fat
An RQ of 0.70 reflects a CO₂:O₂ ratio characteristic of pure fat oxidation, which produces less CO₂ relative to O₂ consumed compared to carbohydrate (RQ = 1.0).
Question 7: Which dietary approach is MOST supported by evidence for reducing inflammation in athletes with high training loads?
- High-protein, low-carbohydrate ketogenic diet
- Mediterranean-style diet rich in omega-3s, polyphenols, and antioxidants (Correct answer)
- Intermittent fasting with a 16:8 eating window
- Elimination diet removing all gluten and dairy
Correct answer: Mediterranean-style diet rich in omega-3s, polyphenols, and antioxidants
The Mediterranean dietary pattern, with its emphasis on omega-3 fatty acids, colorful vegetables, olive oil, and polyphenol-rich foods, has the strongest evidence for reducing systemic inflammation in athletes.
ACSM Nutrition 5
Which type of dietary fiber is MOST effective at lowering LDL cholesterol by binding bile acids in the gastrointestinal tract?