What is the respiratory exchange ratio (RER) for carbohydrates?

The respiratory exchange ratio (RER) for carbohydrates is close to 1. This value signifies that the amount of carbon dioxide produced during the metabolism of carbohydrates is roughly equal to the amount of oxygen consumed. In a state of complete carbohydrate oxidation, the RER reaches about 1.0, indicating efficient utilization of carbohydrates as the primary energy source.

This RER value is important in assessing the fuel source being utilized during exercise or various metabolic states. When the body relies predominantly on fat for energy, the RER decreases to values around 0.7, while an RER above 1 can indicate anaerobic metabolism or increased carbon dioxide production due to other factors.

Understanding RER helps in interpreting metabolic responses to different exercise intensities and dietary compositions, facilitating precise sports nutrition strategies and optimal performance outcomes.