Washington, Aug 9 - Time was when yoga was considered a lifestyle choice in the US, something upper class people did in the luxury of spare time. That image is changing fast, thanks to activists who want to spread the therapeutic benefits of yoga among those who badly need them.

Take, for example, the scene at George Washington University on a recent afternoon. The desks in a classroom were pushed aside and 15 school students were sitting cross-legged on the floor with their eyes closed, breathing deeply.

'For an hour, under the guidance of volunteer yoga teacher Jessi Long, they stretched and lunged, extending their hands toward the ceiling and folding into toe-touching forward bends,' a Washington Post report noted.

At the end, they lay unmoving on their backs in shavasana, or corpse pose, drawing audibly deeper breaths.

'Remember this feeling in your daily life,' said the teacher, rousing them with her voice. 'You can always come back to this feeling of relaxation and release.'

The class, for students in Upward Bound, a programme to prepare low-income youths for college, is part of 'a growing movement to take yoga beyond its reputation as boutique exercise for the well-to-do and use it as therapy for groups such as at-risk and homeless youths, HIV/AIDS patients and torture survivors'.

In Media, Pennsylvania, Sprout Yoga holdsfree classes to people recovering from post-traumatic stress syndrome and eating disorders, whereas Yoga Hope in Boston serves battered women and recovering addicts, the Post reported.

'We're just trying to give people access to the true yoga,' said Adrienne Boxer, executive director of Street Yoga, an Oregon-based organisation that teaches homeless teens and victims of sexual abuse, among others.

'It's a lot more than an asana, or a pose, that you're striking. It's the way that you breathe and the way you relate to others and communicate.'

Mark Lilly, who founded Street Yoga in 2002, said the interest in making yoga freely accessible grew steadily until two years ago - and then it exploded.