Hello, I'm a respiratory physiologist with extensive experience in studying gas exchange and metabolism. I can help you understand the relationship between RER and RQ.

RER and RQ are not the same, although they are closely related and often confused.

* RER (Respiratory Exchange Ratio) is the ratio of carbon dioxide (CO2) produced to oxygen (O2) consumed during respiration, measured at the mouth. It reflects the overall gas exchange in the body, which is influenced by both aerobic and anaerobic metabolism.
* RQ (Respiratory Quotient) is the ratio of CO2 produced to O2 consumed during cellular respiration, specifically aerobic metabolism, and is measured at the cellular level.

Here's a breakdown of the key differences:

* Measurement Location: RER is measured at the mouth, while RQ is measured at the cellular level.
* Metabolic Processes: RER reflects both aerobic and anaerobic metabolism, while RQ only reflects aerobic metabolism.
* Factors Influencing Values: RER can be influenced by factors such as exercise intensity, dietary intake, and the body's metabolic state, while RQ is mainly influenced by the type of fuel being utilized for energy production (e.g., carbohydrates, fats, or proteins).

**Let's consider a few scenarios to illustrate these differences:**

* During strenuous exercise: When you exercise intensely, your body may rely more on anaerobic metabolism for energy production. This results in the production of lactic acid, which can lead to an increase in CO2 production without a corresponding increase in O2 consumption. In this case, RER will be higher than RQ because it reflects the contribution of both aerobic and anaerobic metabolism.
* During rest: At rest, your body primarily uses aerobic metabolism for energy production. In this scenario, RER and RQ are relatively similar.

**Here's a table summarizing the key points:**

| Feature | RER | RQ |
|---|---|---|
| Measurement location | Mouth | Cellular level |
| Metabolic processes | Aerobic and anaerobic | Aerobic only |
| Factors influencing values | Exercise intensity, dietary intake, metabolic state | Fuel type being utilized |

In summary:

RER and RQ are both important indicators of metabolic activity, but they are not interchangeable. RER provides a broader picture of gas exchange, reflecting both aerobic and anaerobic processes, while RQ focuses on the cellular level and provides insight into the type of fuel being utilized.

Understanding the differences between RER and RQ is essential for interpreting respiratory data and gaining a deeper understanding of metabolic processes.

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There's so much confusion going on between the acronyms RER and RQ. At the state of rest the RER, completely known as the respiratory exchange ratio, is actually the same as RQ or respiratory quotient. ... The RQ is a metabolic exchange of gas ratio that is equal to CO2 production over oxygen uptake (CO2/O2).read more >>