jlippinbike

I suppose any distance that qualifies as an endurance ride. If you are fat adapted, then you don't need to micromanage your carb consumption. Being fat adapted does NOT mean you need to avoid carb consumption. I've ridden all the rando distances fat adapted and not had to worry about getting a "carb fix" every 30 to 40 miles along the way. Carbs tend to mess up your gut on the really long rides. I've successfully completed three grand brevets - all of which while I was fat adapted. You do need carbs for speed workouts, i.e., high intensity training. But for endurance workouts and events you should be riding below FTP, and as a result you should be burning mostly fat.