The exceptionally fast growth of yoga as a discipline (and the associated industries- yoga classes, yoga clothing and paraphernalia, books, DVDs, and retreat holidays) has a number of contributing factors. Economic, social, and even religious evolutions all have a part to play in explaining the phenomenon that is modern yoga in the western world.
Beginning with economics, most western yoga practitioners are drawn from the middle to upper middle class, although high-profile and outspoken celebrity trendsetters have played a role in bringing yoga into the mainstream. The relatively strong disposable income available to the middle class makes them more likely to take exercise in a class form, with a paid teacher and over an extended period of time. The complex constructs, forms and movements of yoga are ideally suited to long term courses. Progression in skill allows more advanced forms to be introduced by the teacher, who ideally has a very high level of training.
A lot of yoga practitioners are office workers. They are economically able to access continuing yoga classes, and the high levels of stress (both physical and psychological) that exists in office environments drives them to find outlets. Yoga, of course, is marketed strongly as stress relief.
It is also notable that the proportion of women to men adopting yoga is very high. Accordingly, most yoga clothing and merchandise is aimed at women. Yoga wear, which is designed for simplicity, comfort and ease of movement, is beginning to appear outside exercise sessions and even on the high street. The practice of yoga has to an extent replaced aerobics as the workout of choice for modern women. It is seen as physically safe, progressive, and lacks the association standard gym sessions have with negative body image and ‘ogling’.
Changes in religious attitudes have made it easier for yoga to gain ground. Once seen as suspicious and even cultish, massively increased religious diversity and understanding, as well as the proliferation of eastern philosophies has removed the threatening element from yoga. It now has an excellent reputation as a physical discipline.