Which two gas exchange measurements are used to calculate REE and RQ?

Which two gas exchange measurements are used to calculate REE and RQ?

• A. VO2 and VCO2
• B. VO2 and VO2
• C. VCO2 and VCO2
• D. VE and VO2

Answer: (A)

Indirect calorimetry relies on gas exchange to determine both energy use and substrate oxidation. To calculate resting energy expenditure and the respiratory quotient, you need to know how much oxygen is consumed and how much carbon dioxide is produced during a steady state. VO2 (oxygen uptake) and VCO2 (carbon dioxide production) together let you compute RQ as VCO2 divided by VO2, which reflects the mix of fuel being burned. They also feed the Weir-type equations (or other established equations) that convert these gas exchange values into a value for REE, since the energy yielded per liter of O2 depends on the amount of CO2 produced. Ventilation (VE) measures air movement and does not directly determine substrate use or energy expenditure, and using either VO2 or VCO2 alone cannot yield RQ or REE.

Indirect calorimetry relies on gas exchange to determine both energy use and substrate oxidation. To calculate resting energy expenditure and the respiratory quotient, you need to know how much oxygen is consumed and how much carbon dioxide is produced during a steady state. VO2 (oxygen uptake) and VCO2 (carbon dioxide production) together let you compute RQ as VCO2 divided by VO2, which reflects the mix of fuel being burned. They also feed the Weir-type equations (or other established equations) that convert these gas exchange values into a value for REE, since the energy yielded per liter of O2 depends on the amount of CO2 produced. Ventilation (VE) measures air movement and does not directly determine substrate use or energy expenditure, and using either VO2 or VCO2 alone cannot yield RQ or REE.