The point where fat and carbohydrate oxidation curves cross is sometimes referred to as the anaerobic threshold, but this is only accurate if measured in calories, not grams per minute.

“and there's where those two cross some people call that your Anor robic threshold um but that's where your respiratory quotient is equal if you if you've done this in calories if you do it in grams per minute it won't be because obviously there's way more calories in fat than oxygen”