1. Explain how RER is measured and how RER can be used to reflect usage of substrates.
RER or Respiratory Exchange Ratio is measured by the VCO2 expired divided by the VO2 consumed. The RER can reflect what substrate is being used whether fats or carbohydrates based on what it is closest to. The range is .7 (fats) to 1.0 (carbohydrates).
2. Does RER change with onset of exercise? Does RER change during steady-state over time? What does RER tell us about substrate utilization over time if workload is held constant?
RER decreases with the onset of exercise. Longer moderately intense exercise means your body will usually use fats, and shorter high intensity exercises means that carbohydrates will most likely be used. At steady state,