I've got a kinda trick back. I've been told that I should try doing some excerises that build the deep muscles that support it, so I went to a class called Complete Core (Intermediate). I generally think I'm fairly fit'n healthy, so I thought this would be fine.
You can see the issue here already, right readers? The dangers of hubris.
While there was me shaking around and rolling off this massive Prisoner-esque inflatable fitness ball, svelte girls were balancing themselves perfectly atop theirs in full Superman-in-flight positions. The instructor (a tall blonde lady whose midriff appears to be made out of some futuristic, rock-hard polymer, and could almost certainly kick my ass thrice over) was kind enough to give me a 'good try.'
I just tried to stand up and had jelly legs. Young, healthy 26-year old males: know your limits.