Oxygen consumption in METS and energy expenditure in kilocalories are paired correctly in which option?

• A. Oxygen consumption: METS; Energy expenditure: Kilocalories
• B. Oxygen consumption: Kilocalories; Energy expenditure: METS
• C. Oxygen consumption: Liters per minute; Energy expenditure: kcals
• D. Oxygen consumption: METS; Energy expenditure: Joules

Answer: (A)

METs express how much oxygen is used during activity relative to rest, while energy expenditure is usually given in kilocalories. This pairing fits practice: oxygen cost is described in METs, and the actual energy burned is reported in kcal. A handy relation is that 1 MET ≈ 3.5 mL O2 per kg per minute, roughly equivalent to 1 kcal per kg per hour. So at higher METs you can estimate kcal burned for a person’s body weight, linking oxygen cost to energy cost. The other options mix units in ways that aren’t the standard pairing: oxygen cost isn’t typically reported directly in kilocalories, and while liters per minute or joules are valid units, the conventional pairing uses METs for oxygen cost and kilocalories for energy cost.