mel,

I think you are mistaken yoga for contortionists...although there is a belief that a lof of these contortionists originated from yoga.

"YOGA" is in essence, learning about your body. Its limitations are based on what you can do and what you can't do...which is endless...

everyone's levels are different. It's like swimming for health and swimming like Michael Phelps...I don't know if Michael Phelps would be able to maintain that speed when he hits 60 or 80...

Yoga is self-awareness...there are many different programs and exercises that it has, from beginners to the experts' levels...it is all about where we want our bodies to go.

Just like there are people that jog 4 miles and there are those that jog 20 miles...

for example: (I always use this as an example to illustrate yoga)

there is a "corpse" position in yoga where you simply lie down on the floor, you place your arms in 45 degree angle and you try to relax and actually fall asleep..

THAT, is yoga...part of it..

the different levels are our own challenge levels...some of us like our eggs well done and some of us like our eggs runny...

yoga has that flexibility to do that...

it tries to incorporate healthy living and breathing and reaching that mind/body connection...

for myself, the nexus of that is very crucial as I age...as my body becomes more inflexible and my spines are hurting like crazy and my pain levels are high...I find yoga a nice escape...milli-meter by milli-meter is my own personal goal, but one can stay in the same position of where their levels are at, if they so shall choose....

a really good yogo teacher is not going to tell you to put your legs behind your head...a really good yoga teacher is going to help you become more flexible on your own terms...

I think that's important especially in women...osteoporosis can be helped with yoga because of using your body weight to strengthen your muscles and bones...

I think Contortionists follow an EXTREME form of routine and exercises and I would not recommend that to anyone....

but yoga is about balance, peace, and harmony...being one with your body...

and it's a gradual pace...to where you are comfortable at, at YOUR exact moment....

anyways...there is deep philosophy behind yoga but I am not an expert..these are just the ones I walked away with...as with everything else, there are always 3 sets of opinions and studies and contrasts...find the ones that correlated with you the best...