Fuel partitioning tests should be conducted on a separate day from VO2 max tests, ideally with a fasting protocol in the morning and a submaximal effort.

“we tend to do these separately now so we don't use the day of the V2 Max test to do the fuel partitioning test um so we want to measure fat oxidation on a totally different day um like we'll usually separate by a day even right so you'll do your V2 Max test on Monday and we'll do it like this kind of way where we you know again agree completely like you should have all the carbs in the world we actually like to standardize the fat oxidation test to a fasting test okay and just that way it's just always the same it's like you're going to do it in the morning you're fasted um it's a submaximal effort we're not pushing you to maximum”