Do You Have a Calary Deficit?

If you did three hours of cardio a day and didn't eat at a calory deficit, but maybe ate just slightly above maintenance, could you then pull yourself into a defi yes. Would that be an extremely miserable way to live? Yes. Is it going to be very hard to sustain? Yes. You can't outrun your fork. It is just extremely hard to do. But it's possible. I just wouldn't recommend it.