What is the numerator in the energy cost calculation for walking?

What is the numerator in the energy cost calculation for walking?

• A. Step length
• B. Gait speed
• C. Oxygen cost
• D. Oxygen consumption

Answer: (D)

The energy cost of walking is typically expressed as how much energy you use to move a unit of distance. To get that, you take the rate of energy use (how much oxygen you’re consuming per minute) and divide by how fast you’re moving (speed). Oxygen consumption reflects the metabolic rate—the actual energy being spent—so it sits in the numerator. Step length and gait speed describe how you move, but they’re not the measure of energy use itself. Oxygen cost is the resulting metric per unit distance, calculated from the oxygen consumption (in the numerator) and the speed (in the denominator). So the numerator is oxygen consumption.

The energy cost of walking is typically expressed as how much energy you use to move a unit of distance. To get that, you take the rate of energy use (how much oxygen you’re consuming per minute) and divide by how fast you’re moving (speed). Oxygen consumption reflects the metabolic rate—the actual energy being spent—so it sits in the numerator. Step length and gait speed describe how you move, but they’re not the measure of energy use itself. Oxygen cost is the resulting metric per unit distance, calculated from the oxygen consumption (in the numerator) and the speed (in the denominator). So the numerator is oxygen consumption.