For the Macedonia Ridge Trail Double Loop FKT one must complete the full 6.5mi loop once in either direction. There is a very technical, rocky section along the Western side of the loop that is particularly challenging. Whether it's tougher up or down it is up for debate. As Lee noted though... those rocks are very slippery when wet! You're best off saving your attempt for dry conditions.
It's a fun, scenic, well-marked & challenging loop! Can't wait to see what others can throw down on it.