When did you have the upper body strength? Pre-puberty? Thing is, when our (women's) hips come in, our shoulders and elbows have to adjust so our arms aren't trying to hang inside our hips. And our centre of gravity moves down - useful for staying upright, not so handy for being upside down. You might be lucky, but I know I'm not :-).

And yeah, better to move the goal time if there's a specific goal you have in mind, but I wasn't sure if it was the time or the goal that was important to you.