Reply to Djing for LONG periods of time

Id like to get some input / tips from anyone here at DJTT . I booked a GIG djing an obstacle race , all ages event , obviously TOP40 and High Energy music with some MCing, but my question has anyone done something like this? It is a 12 hour event , if you have; what are your thoughts on approaching the music? I was probably going to do 3-4 hours of programming then just vary it up as the crowd will cycle in 2-4 hour waves.