Protein is the last of the macro-nutrients to be turned into fuel and then usually only in times of starvation.
Why are you telling me this? I'm fully aware of the process. I already said it was a quote from Polar's support website. My only doubt is that our watches can accurately determine when we stop using carbs for fuel and then tell us how much fat we burned. Yes, there are calculations one could make, but they're based off of assumptions which Polar states they are doing.
