Being well rested for a long distance hike is really important. In the week before the hike, try to arrange your schedule so that you get several nights of full and restful sleep, but realize that the Friday night before hike day is not likely to be one of those 'good' nights (the 100K starts at 3 AM, and even the 50K, starting at 10 AM, can induce pre-hike jitters).

If you have trouble sleeping, check out this WikiHow article on How to Sleep Better.