Arms sway in the gloom of the hall as a group of 11-year-olds make their first attempt at a yoga position known as the tree. Gradually, the gaze of a young woman in the front row settles, unseeing, on the middle distance.
Surrounded by jacaranda trees and hedges of bougainvillaea outside Dehra Dun in northern India, Welham girls' high echoes with the sounds of activity.
For 10 years yoga has been on the curriculum of this prestigious private school and at its counterpart, the Doon school for boys. It is now compulsory for 11 to 15-year-olds who can opt to take an exam in the exercise regime.
The yoga classes have been designed with children in mind. Swati and Rajiv Chanchani evolved the programme at the behest of their guru BKS Iyengar who evolved the yoga style named after him.
Lessons for younger children aim to harness their energy, resilience and sense of fun. Older children spend more time learning about yoga philosophy. The syllabus has been externally accredited.
Yoga is thought to be particularly beneficial for secondary-age pupils as it regulates the functioning of the endocrine and adrenalin glands, helping to eliminate acne and emotional extremes. Some poses are said to relieve menstrual pain, overcome headaches and combat fatigue.
In the Welham classes pupils are encouraged to gauge their own performance.
This often appeals to young people who have only been ballast on the games team. Teachers say concentration in other lessons improves after students have studied yoga.
However, the shortage of yoga teachers in India has made it difficult to spread the programme. In the UK there are 800 registered Iyengar yoga teachers, but few work in schools.
Yoga for children, a complete illustrated guide to yoga, including a manual for parents and teachers, by Swati Chanchani and Rajiv Chanchani is published by UBSPD, and is available from www.upspd.com and www.gobookshopping.com