If you practice yoga on a regular basis it is very beneficial to both mind and body. When you do the postures you are instructed to breathe in and out as you move into the postures – this helps take oxygen to different parts of the body. You also learn to breathe more deeply, so each breath you take is more effective. The postures help to stretch your body and make it more supple – you become more aware of your body (even the parts that you didn’t know you have). You also learn to calm your mind so that you can focus more easily (this could be partly because aligning your breathing to your movements needs quite a bit of concentration and you don’t have space to think of all the rubbish that’s usually flitting through your mind!).
For the mind it opens up your awareness of your body and self. You learn how to control yourself through the methods that you’re taught and you can incorporate its concept to life. There are all kinds of teachers and classes so I can’t say what you’ll take away from it but there is a whole spectrum of things that yoga does to help you enrich your lifestyle and help you feel good about yourself. Your body simply follows the well-being of the mind so if you really stretch your limits you will have that perfect form that you achieve for all the while maximizing your thinking power.