The variety of yoga styles available today can look like a long process of gradual branching. Most of it traces to a small number of twentieth-century teachers and their disagreements.
Posture was a minor element historically
Classical texts on yoga are concerned mainly with ethical discipline, breath regulation, withdrawal of the senses and stages of concentration.
Physical postures appear, but as seated positions for sustained meditation rather than as a sequence of movements performed for their own sake.
The elaborate postural repertoire familiar today is largely a modern construction, assembled during a period when physical culture was a widespread preoccupation.
A single teaching lineage did most of the work
A great deal of what is practised internationally traces to one teacher working in southern India in the early twentieth century, whose students carried different emphases abroad.
He taught individuals rather than classes, adapting sequences to the person in front of him, which meant students trained at different ages received substantially different instruction.
Those differences hardened into distinct schools once each student began teaching in their own name, and the variation was later read as separate traditions.
The main axes of divergence
Styles differ chiefly along a few dimensions rather than in unrelated ways, and most named schools can be located by their position on each.
- Whether postures are held at length or linked continuously with the breath.
- Whether the sequence is fixed or varies by session and by student.
- How much attention goes to precise alignment against a stated ideal.
Almost every branded style is a particular combination of these choices, which explains why practitioners moving between them find the vocabulary familiar.
Export shaped the emphasis
As the practice moved to Europe and North America, it entered a market of gyms and studios where physical benefit was the accepted reason to attend.
Philosophical and devotional elements were reduced accordingly, not by decree but because classes were sold, scheduled and priced like other fitness offerings.
The result is that the international mainstream is substantially more postural than most of the tradition it descends from.
Style choice is mostly about fit
Because the underlying postures overlap heavily, the difference between schools is largely one of pace, structure and how instruction is delivered.
Vigorous flowing styles place real cardiovascular and joint demand, while slower held styles suit different requirements, so the choice is practical rather than doctrinal.
Anyone with joint problems, high blood pressure, glaucoma or a recent injury should discuss suitability with both a clinician and an experienced teacher before starting.