You need to be a pretty decent middle route rider at least.
Experience riding every road trial you can for a year or so before having a go. Bike fitness is more important than going to the gym.
And remember the videos flatten the sections. And they don't show the big holes amongst the rocks.
Also a lot of the sections are big and intimidating nowadays. And if it's wet you can't see what your riding to make it even harder.
It can be a very expensive and demanding week but if you havn't tried it you will never know if it's for you. Some have one go and never again. But most keep going back for more every year.
It was my favourite trial but too old for it now.