There is so much to say about the practice, philosophy and history of yoga, so here are just a few pointers.
Yoga is often translated as 'union' - bringing together of the mind, body and soul through physical asanas (postures) and breath. Classically there are eight limbs of yoga, moving from the postures and breathing exercises commonly known in the West, to concentration and meditation bringing spiritual fulfilment.
How you benefit from yoga will be up to you and your circumstances as they change. Whether you are looking for relaxation, greater suppleness and strength, solutions for chronic aches and pains, or just a chance to 'be' every now and again, yoga can be for you.
Excitingly, there are increasing amounts of peer-reviewed science showing the benefits of yoga. The Iyengar Yoga National Association of the United States (IYNAUS) has had a research committee since the early 1990s, to foster medical research on yoga-related issues. Their website gives a number of fascinating articles and links, including a compilation of research papers from 2008 (pdf).
in the UK, a large trial on yoga for lower back pain is described on the Yoga for Healthy Lower Backs website. Many of the postures used in that programme are also taught in general Iyengar yoga classes. Yoga Therapy for the Mind is another example from the UK, encouraging research on yoga for mental health issues.
There are starting to be some good online resources for Iyengar yoga, both with classes and pose descriptions as well as articles about the principles behind the practice. I recommend the useful resource at YogaVastu, including online classes, as well as YogaSelection (website) and RoadsToBliss youtube channel for online videos to help your home practice.
I teach Iyengar yoga, which promotes strength and flexibility through a series of poses that emphasise stretching, attentive breathing and relaxation. Iyengar teachers help students to focus on correct alignment for safe poses with maximum benefit for flexibility and wellbeing. The tradition was developed by BKS Iyengar, to whom we owe much.
It is worth remembering though that Iyengar himself said "how can I give my name to a universal art? It is wrong to differentiate traditional yoga from Iyengar yoga...there is no distinction between one yoga and another: they all have the same root and the same purpose". Neverthless, we record his ability to bring out the hidden depths of yoga through a deep understanding of all eight limbs of the practice by calling it Iyengar yoga today.
Classes generally start with simple poses and move towards more advanced poses, ending with a period of relaxation and breathing techniques. The classes can be hard work, as the poses involve intense stretching; however, you leave the class feeling lighter and calmer. Props, such as blocks and belts, are sometimes used in class to allow those with less strength or flexibility to work correctly and achieve their full potential.
The trade mark above is used to protect and maintain the quality and reputation of the practice of Iyengar yoga. It can be exhibited only by teachers who comply with Iyengar standards and who undertake ongoing professional training. Remember that ALL Iyengar teachers will have had at least FIVE years experience by the time they are a teacher: 3 years practice and 2 years teacher training as a minimum. So although the new Iyengar teachers are called 'introductory' they still have a lot more than the basic standard 200hr training which is the basis for much yoga training around the world today.You can read more on the Iyengar Yoga (UK) site and there's a little booklet with more information here.