What does the Respiratory Quotient (RQ) represent?

The Respiratory Quotient (RQ) is defined as the ratio of carbon dioxide produced to oxygen consumed during metabolism. It provides insight into the type of fuel being used for energy by the body—whether carbohydrates or fats. For example, when carbohydrates are the primary fuel source, RQ tends to be closer to 1.0, whereas fats have a lower RQ, around 0.7. This measure is significant in exercise physiology and nutrition, as it helps trainers and individuals understand energy metabolism during various levels of physical activity.

Understanding RQ can assist fitness professionals in tailoring training and nutritional strategies to optimize performance and recovery based on the predominant energy source being utilized. This distinction is crucial for designing effective fitness programs. The other options, while related to respiratory and metabolic functions, do not accurately define the specific concept of respiratory quotient.