ACSM-EP Metabolic Calculations 5 — Questions and Answers
Question 1: A 75 kg athlete completes a 6-minute walk test and achieves an estimated VO2 of 22 mL/kg/min. How many kilocalories per minute is he expending?
- 3.9 kcal/min
- 5.5 kcal/min
- 7.9 kcal/min (Correct answer)
- 11.0 kcal/min
Correct answer: 7.9 kcal/min
Absolute VO2 = 22 × 75 = 1650 mL/min = 1.65 L/min; kcal/min ≈ 1.65 × 5 = 8.25 ≈ closest 7.9 kcal/min using 4.8–5.0 kcal/L.
Question 2: When prescribing exercise using the VO2 reserve (VO2R) method, which formula is used to calculate target VO2?
- Target VO2 = %intensity × VO2max
- Target VO2 = %intensity × (VO2max − VO2rest) + VO2rest (Correct answer)
- Target VO2 = VO2max − %intensity × VO2rest
- Target VO2 = %intensity × (VO2max + VO2rest)
Correct answer: Target VO2 = %intensity × (VO2max − VO2rest) + VO2rest
The VO2R method mirrors the Karvonen HRR formula: target VO2 = intensity% × (VO2max − VO2rest) + VO2rest.
Question 3: Which ACSM metabolic equation is most appropriate for a client walking at 1.5 mph (40.2 m/min)?
- Running equation
- Leg ergometer equation
- Walking equation (Correct answer)
- Arm ergometer equation
Correct answer: Walking equation
The ACSM walking equation is valid for speeds of 50–100 m/min; although 40.2 m/min is slightly below this range, it remains the most appropriate equation for walking-pace activity.
Question 4: A subject's RER rises from 0.82 at rest to 1.10 during maximal exercise. What does an RER above 1.0 during exercise indicate?
- Pure fat combustion
- Hyperventilation and bicarbonate buffering of lactic acid (Correct answer)
- Reduced cardiac output
- Protein becoming the dominant fuel
Correct answer: Hyperventilation and bicarbonate buffering of lactic acid
RER > 1.0 reflects CO2 released from bicarbonate buffering of accumulated lactic acid, plus hyperventilation, not from metabolism alone.
Question 5: A 68 kg person expends 420 kcal during a 60-minute cycling session. What was the average absolute VO2 (L/min) during the session?
- 0.7 L/min
- 1.4 L/min (Correct answer)
- 2.1 L/min
- 2.8 L/min
Correct answer: 1.4 L/min
420 kcal / 60 min = 7 kcal/min; VO2 (L/min) = 7 / 5 = 1.4 L/min (using ~5 kcal per liter of O2).
Question 6: In the ACSM running equation, the vertical component coefficient is 0.9 rather than 1.8 (as in walking). Why?
- Runners are more efficient on inclines than walkers (Correct answer)
- Running already has a higher horizontal cost, so vertical is proportionally smaller
- The 0.9 coefficient reflects only one leg's contribution
- Incline running uses the same muscles as level running
Correct answer: Runners are more efficient on inclines than walkers
Runners are mechanically more efficient going uphill than walkers because of their spring-like gait mechanics, requiring less metabolic energy per unit of vertical displacement.
Question 7: A client needs to achieve a target VO2 of 28 mL/kg/min on a cycle ergometer. She weighs 65 kg. What work rate (kgm/min) should be set? (Use ACSM leg ergometer equation; assume unloaded VO2 = 3.5 mL/kg/min)
- 583 kgm/min
- 715 kgm/min
- 875 kgm/min (Correct answer)
- 1040 kgm/min
Correct answer: 875 kgm/min
Net VO2 = 28 − 3.5 = 24.5 mL/kg/min; work rate = (24.5 × 65) / 1.8 = 1592.5 / 1.8 ≈ 885 ≈ 875 kgm/min.
ACSM-EP Metabolic Calculations 5
A 75 kg athlete completes a 6-minute walk test and achieves an estimated VO2 of 22 mL/kg/min.
How many kilocalories per minute is he expending?