I just want to say thank you guys for replying. All this information is great.
I don't like to quit or give up but I'm only human. Being that much more prepared just gives a better chance of making it through the whole event.
I really want to go to a 24 hour event but I know there is no way I'll last without getting rest.
At least now I'm starting to get a better idea what is needed and also that being mentally prepared goes a very long way.