THe day before thing is for saftey, it comes from boxing: Guys will still cut for the day of the fight, and they will go in dehydrated and get hurt (getting hit in the head when dehydrated can cause brain damage more easily). So, they have the weight in the day before. There is no easy way around it. Unless, for instance, you are weighed like a week before and you have to weigh in at a certain number, close to fighting weight. Then on the day of the fight they are weighed again. Since most guys cut weight though, it might be better if everybody fought in their natural weight classes.