One way to describe the relationship of the breath to the body during asanas* (yoga postures) which I really like, and think is very helpful to remember is...
"All movement is contained in the breath... breathe determines movement".
Meaning, the breath leads, and is an integral part of all of the exercises we do in yoga. Unlike most physical activity where little or no thought is given to our breathing (except things like swimming, where obviously there isn't much choice!) the breath in yoga is equally important as the movements of our body. This is what helps yoga transcend from merely stretching the body to being a holistic form of exercise for the nervous, respiratory and digestive systems (as well as a excellent way to get a sexy butt... also very important of course :))
So while you may snicker at my incessant harping on about inhaling and exhaling (not naming any names *coughDCcough*), paying particular attention to our breath and using it in the specific way prescribed by each exercise is a very important part of doing yoga effectively. More important than being able to stretch into that impressive looking pose even! WAY MORE!
There are various ways the breath is tied to movement during asanas which can be generally boiled down to: exhale - moving forward, twisting, compressing; inhale - moving backwards, moving limbs away from the body, opening; but as a beginner you are not expected to remember this! Just follow the breath instructions the teacher is giving with each pose - with the awareness that they are not something "extra" or optional but rather an integral part of the class - and you will be fine!
More than fine even, you will be an amazing yoga practitioner, no matter how far (or not far) you can bend :)
I will definitely be covering the breath and breathing techniques more and more on the blog, just wanted to give you a quick word up on the importance of the breath, so you can start being aware of trying to consciously practice it more in class... to get even more out of the wonder that is... BROGA!
* Asanas are the exercise component of yoga that we in the west think of then we hear the word, but there are actually eight limbs of yoga! And asanas comes only third! I will be writing on the other seven in the near future... hope I have piqued your interest for more to come :)