Bike Posture
When I got my bike fit, he told me to stick my chest out and bend at the hips. Do not bend the back like you would when you touch your toes.
There are lots of pictures of pro's that can show you posture better than I can describe it. I typed "McCormick Triathlete" into Google images and this came up. I would not suggest it.
http://chemistry.boisestate.edu/people/mikemccormick/
HAHAH wow I have a hard enough time just feel stable enough to stay on the damn bike, never mind Mike McCormick-style.
What is the proper posture for the bike?

And sometimes this

The "correct" position is whatever is most comfortable.
most comfortable is probably on a recumbent.
theres a short piece on posture in this month's triathlete magazine. there are two pics before and after and apparently the after like doubled the guy's watts output.
"correct" is what triscott said. funny thing though. Lance Armstrong looked like a frog to me. he got all bent up in the middle so much so that i once was read a theory that the huge hump created in his mid back worked to foil air making him more aerodynamic. it certainly doesn't appear comfortable.
my son and i ride together alot and compared to him i ride like i am in the tour and he like a tourist on a beach cruiser (he's faster than me...reluctantly). but as low as i am, i am comfy and happy... but not on the trainer. my arms get tired. i am always shifting around, can't stand it. guess its cause it's right there in my face, thinking about it.



What is the proper posture for the bike?
My mom rides with her back bent and sort of hangs over herself, whereas I bend my arms slightly bent but try to keep my head and shoulders up. (The bike shop said that if your bike is fitted properly then don't worry about your posture-- but lately I've been on a stationary bike (rains a lot in Seattle) and I want to make sure I'm doing it properly.) I've been sore in my shoulders lately but that may just be because I don't have the muscles yet...
Thanks so much in advance everyone!