RER in exercise

RER, or Respiratory Exchange Ratio, measures the ratio of carbon dioxide produced to oxygen consumed during exercise. It helps determine which fuel source your body primarily uses—fat or carbohydrates. An RER near 0.7 indicates mostly fat burning, while an RER near 1.0 suggests carbohydrate is the main fuel. Values above 1.0 can occur during intense exercise, reflecting increased carbon dioxide production from acid buffering. Monitoring RER provides insights into exercise intensity and metabolic processes, aiding in training optimization and performance assessment.