Over the last 20 years, the popularity of yoga has increased from nearly no interest to being one of the most popular exercise regimes around. To match the increasing demand for yoga, more and more yoga centers are opening all the time. For those of us looking for something new, or just starting out for the first time, the choices can be daunting.

There are many different schools and styles of yoga including Iyengar, Ashtanga, power yoga, Bikram (hot), Kundilini, Viniyoga to name just a few. Although all of these schools of yoga essentially teach the same Hatha yoga asanas (yoga postures), the objectives of the class and the way the postures are performed and taught are very different for each.

In addition every yoga teacher has their own characteristics, emphasis and approach to teaching which affects the class and learning experience.

While so many choices can be daunting, it also means that there's so much diversity, we're bound to find a style and a teacher that we like. If we don't like a school of yoga, or a yoga teacher - we can try something else.

While personal preference will guide much of our selection process both for the school of yoga and the teacher, finding an experienced and high quality teacher is the most important consideration.

With the increasing popularity of yoga the demand for teachers and peoples desire to take their practice to the next level means that thousands of people take some kind of certification or registration each year. But with so many new teachers around, it's impossible for them all to be to be of the highest standards.

In addition, the absence of formal regulation of the training and certification for yoga it's difficult to know before a class how good a teacher will be. Without formal standards, an individual can become a teacher with very little personal yoga practice and experience. Experience is important for overall understanding but the amount of and quality of teacher training is also important. The quality of yoga teacher training courses and certification varies enormously. Currently certification can take from a year or more for some specializations to merely a 1 or 2 day intensive program. A 200 hour program of learning and supervised teaching practice is quite standard. What's more the format can vary from retreats with formal examinations to correspondence courses and certification over the internet.

With the teacher being so important, and the options on teacher training so varied, the responsibility for selecting a high quality yoga teacher is passed to the students and should not be taken lightly.

The yoga instructor is elemental in setting the tone of the class. The teacher, their style of yoga and their approach to teaching, can not only determine whether you enjoy a session, but whether you like yoga at all. But more than that the yoga teacher, the routines they teach and the quality of their teaching will control how much benefit we get from the practice.

While there are many complexities that determine whether we enjoy a class, there are two things a yoga teacher must always do.

The teacher must guide our practice on a macro-level with a well rounded practice. It is important that we develop our bodies in a balanced and uniform manner which means in a single session we should develop strength, flexibility to all muscles and joints without over emphasis on one area that could lead to strains and injury. On top of this it's important perform balancing poses that improve body co-ordination and improve concentration. Finally every pose, particularly the flexion and compression of the back, has a counter pose. A well designed yoga routine takes this into consideration to prevent over straining muscles and reduce soreness.

The yoga teacher must guide our learning on a micro-level with correct technique and alignment to increase our abilities without injury. Firstly the teacher needs to provide demonstration and detailed instruction on how to safely enter, hold and exit the poses. The descriptions should include details about correct steps to enter the pose as well as key points to consider such as alignment and muscles to use.

In addition the teacher needs to quickly gauge each individual's abilities so they can advise on more basic or more advanced variations as appropriate. Then the teacher needs to observe how we are performing each pose helping to correct errors that may lead to injuries. Correction of poses can include verbal descriptions or by physical assistance and repositioning.

The best way to choose a yoga teacher is by giving their class a try. We usually know before the end of the first class whether we're going to be able to follow this style of yoga and the teacher.

However, if we have less experience of yoga, attending a new school of yoga or a new teacher may be more intimidating. In this case it's worthwhile talking with the teacher before taking their lessons, to find out more about them and tell them about ourselves. Things to consider may include:

There are a couple of other "tells" that may help you judge whether a teacher is sufficiently experienced. Firstly, does the teacher talk as if they are genuinely enthusiastic about yoga, it's benefits for the body, mind and spirit and sharing that with their students? Secondly, do they come across as being genuinely knowledgeable about yoga? Such as knowing and using the Sanskrit names of the yoga poses. While it doesn't guarantee that the teacher is experienced or good at teaching, it does at least indicate they have spent some time learning their practice.

If you don't find the right yoga style or teacher right away, then keep looking. With so many options you're bound to find something soon enough. The health benefits of yoga are worth the search and you'll learn plenty about yoga, your body and yourself along the way.