Then the guru Patanjali wrote the Yoga Sutra in the early part of the first millennium, and offered an eight-limbed path that was to become a central aspect of the yoga systems that followed. Hatha yoga, out of which came the physical postures or asanas the Western world now embraces, first appeared in the ninth or tenth century AD.

Still, yoga developed and changed. A few of the types mentioned in the story include:

Sivananda Vedanta: It was brought to North America by Swami Vishnu-devananda under the instruction of his guru, Swami Sivananda of Rishikesh, India. He began travelling and teaching throughout the U.S. in 1957 and established the first Sivananda Yoga Vedanta Centre in Montreal in 1959. There are almost 80 Sivananda locations around the world.

"This is a traditional type of hatha yoga, " says Sankara Chaitanya, co-director of the Sivananda Yoga Centre in Montreal, consisting of 12 basic postures, breathing exercises (pranayama) and relaxation. "The ultimate goal of the yoga practice is to reach a meditative state."

Kripalu: At the Joy of Yoga Studio, founder Kelly McGrath describes the Kripalu yoga she teaches as a branch of hatha yoga that links fluid movements with deep yogic breathing - the style is called vinyasa flow.

"We practise very precise alignments combined with meditation, so mindfulness is a very important part of Kripalu yoga," McGrath says. "It's really teaching people how to develop a sense of inner listening - to their own inner wisdom - and being able to respond to that with clarity."

This way, she says, they can break unhealthy life patterns.

Another aspect is spiritual intention, McGrath says. " We help to teach people to cultivate qualities of the heart, loving kindness and equanimity. It's a journey, like all yoga styles."

Ashtanga: It's a dynamic form of yoga developed by Sri K. Pattabhi Jois of Mysore, India, considered the biggest influence on hatha yoga in the West, says Mark Darby of Sattva Yoga Shala.

"The goal of Ashtanga yoga is to purify the body in a dynamic way," Darby says. "The body becomes toned and the nervous system is calmed because of the postures."

Breath and movement kindle an internal heat and are key components, he says.

The practice includes meditation, but is considered a more physical type of yoga, described by some as "a moving meditation."

SEVEN SIGNS OF CHANGE

You know you're a "transformed" yoga practitioner when ...

You choose yoga over a stiff drink to calm down.

In stressful interactions, you want to find out what the other person thinks.

If someone cuts you off when driving, you tell yourself the other person just needs to get somewhere, and you let them go.

You don't have to tell anybody you practise yoga.

You won't go a day without yoga.

If things fall through, you remember there's always tomorrow.

It doesn't matter if you can get your foot behind your head.