Try sitting really hard in your jumps. Like as you snap your legs up into your jump, sit. Hope this helps. :D
P.S. you might fall on your butt the first few times, but that's kinda normal.
I love having level 5 in the arena both days because I think it has the best seating (not a bad seat in there) and because I personally thought of the level 5's being the arena was something to look forward to. But that's just me. :)