Excuse my ignorance if there is an obvious answer to my question…
Why do people bother carbing up or carb cycling for exercise if the body can run more efficiently on fat once you are fat adapted?
Or do people only do that during the adaption phase when they aren’t quite burning fat yet?
Why do people introduce carbs again? Or is that mostly athletes?
Thanks 
IN MY OPINION …
You just hit the nail on the head. Carbs aren’t necessary for exercise. I think some people do it because: they can (assuming they’re burning through most of it); and/or they just can’t get over the concept of the body needing carbs at some point, despite science and evolutionary history to the contrary.
I like your response.
I’m now fat adapted and plan on taking up crossfit again but really don’t want to have to eat carbs just to exercise, why can’t my body feed on it’s fat during a workout? I assume that’s what happens.
It’s a subjective topic. Carbs around exercise are for metabolic purposes, to prevent a metabolic slowdown, called the “Starvation Effect”. If not experiencing this effect, they’re not necessary. When facing starvation, the usual response for humans was to reduce activity. Since people training want to continue training, they consume carbs instead. It’s also usually in the context of a calorically restricted nutritional pattern.
I honestly wonder myself. I have read from ultra runners who don’t do it. And if you can run 100+ miles without adding carbs, I’m certainly not going to to do it running 6+ miles.
There are intense activities (sprints, for example) that I think are more glycolytic and some people find that a carb up before those sessions does help performance.
Running is different. You’re using primarily Type 1 slow twitch muscle fibers in a sustained way. Type 1 fibers (like the heart) run very efficiently on ketones. It’s when you’re using Type 2 fibers during activities like weight training that it’s more applicable.
That’s why LISS (low impact steady state) is typically advised for fat loss rather than HIIT. (high intensity interval training). During LISS you don’t cross the lactic acid threshold. With HIIT you should cross it with each high intensity interval.