Need help learning to sit down!

[Magellan]

Here's the deal....I've only been riding dirt bikes about 6 years now (I started when I was 32 in 2000).

I also do some trials riding. The problem I'm having is that I am more comfortable standing up than I am sitting down. I am working my way up to the long course enduros, but after standing for 35 miles I'm beat. The guys passing me are always sitting down, riding out the berms, etc.

Whenever I sit, I feel like I am steering the bike with the bars and not leaning it, etc.

Thanks,