The Indian Ocean tsunami which occurred in December 2004 affected various parts of South-East Asia including the Andaman Islands. These islands consist of an archipelago in the Bay of Bengal, inhabited by hunter-gatherers who are believed to have originated from the Paleolithic age and Neolithic colonies of South-East Asia (1). The present population includes the endogenous people (EP) as well as settlers from the mainland (ML), i.e. India.

A month after the tsunami there was an initiative to introduce stress management techniques for the people who were temporarily relocated in camps in the capital (Port Blair), as their homes were destroyed. At that stage their immediate needs were provided. However, most of them were anxious and distressed, this being related to (i) the possible recurrence of the tsunami especially in the presence of ‘after-shocks’, (ii) being displaced and (iii) reconstructing their lives. Most of them also had to come to terms with losing their relatives, friends and property.

As a part of this initiative a survey was conducted on 646 people of whom 328 were endogenous people and 318 were mainland settlers (2). The two populations differed in their: (i) social organization, as the EP group form close communities under a ‘tribal leader’, whereas the ML group has the family as the main unit and (ii) religion, as most of the EP group follow Christianity, whereas most of the ML group are Hindus. The ML group had higher levels for four indicators of distress (i.e. anxiety, fear, sadness and disturbed sleep) which are commonly reported by disaster survivors (3). The groups also differed in their coping strategies with the EP group choosing interpersonal contact while the ML group chose denial strategies especially alcohol.

Yoga is an ancient Indian science which includes the practice of loosening exercises (sithilikarana vyayama), specific postures (asanas), cleansing practices (kriyas), voluntarily regulated breathing (pranayamas), yoga-based guided relaxation and meditation (dhyana) (4). Yoga training has been reported to decrease heart rate and breath rate, the signs of reduced psycho-physiological arousal in normal volunteers (5). Significant reductions were shown for depression, anger, anxiety, neurotic symptoms and low frequency heart rate variability in 17 patients with depression following training in Iyengar yoga (6).

The present study was designed to compare responses of the EP and ML groups to a 1 week yoga program, based on psycho-physiological variables, as well as their self rated indicators of distress.

The electrocardiogram (EKG), breath rate and skin resistance were recorded in all participants. These recordings were made simultaneously using a digital four channel polygraph (Medicaid, Chandigarh, India), with the participants seated in a quiet room which was set aside for medical treatment of camp participants. After coming to the recording room the participants were asked to be seated for 5min followed by 10min of recording.

Swami Vivekananda Yoga Research Foundation, Bangalore is an established yoga center specializing in yoga education and using yoga as a therapy. The institute has developed an integrated yoga program based on the principles mentioned above and the ‘eight limbed yoga’ (astanga yoga) of Sage Patanjali which acts at different levels of existence. These eight ‘limbs’ are: (i and ii) rules for good conduct (yamas and niyamas), (iii) physical postures (asanas), (iv) voluntarily regulated breathing (pranayama), (v) sensory withdrawal (prathyahara), (vi) focused thinking (dharana), (vii) meditation (dhyana) and (viii) experience of transcendence (samadhi). The practices which act at different levels are as follows: (i) and (ii) act at the level of rational thinking and judgment; (iii) at the physical level; (iv) at the level of subtle life energy; (v) and (vi) at the level of emotional thinking (vii) and (viii) at the level of complete health and happiness. This traditional style of yoga has come to be known as ‘Vivekananda Yoga’ (8).

Loosening exercises (Sithilikarana Vyayama, in Sanskrit) are a set of practices intended to increase mobility of joints and to prepare for the practice of yoga postures. The techniques involve repetitive movements of all the joints from the toes up to the neck. For example, more complex joints such as the shoulder could have movements such as rotation, flexion, extension, abduction and adduction.

For the practice of yoga postures (asanas) participants were asked to be in a posture as long as they could with comfort and with normal breathing. The following yoga postures were taught: mountain posture (tadasana), lateral arc posture (ardhakatichakrasana), hand-to-foot posture (padahasthasana), half wheel posture (ardhachakrasana), sitting with a sideways twist posture (vakrasana), back-stretching posture (paschimothanasana), half lotus posture (ardha-padmasana), diamond posture (vajrasana), camel posture (ushtrasana), moon posture (shashankasana), crocodile posture (makarasana), cobra posture (bhujangasana), locust posture (shalabhasana), shoulder stand posture (sarvangasana), fish posture (matsyasana), and corpse posture (shavasana). These postures are shown in Fig. 1.

Figure 1. Illustration of selected loosening excercises [sithilikarana vyayama] and yoga postures [asanas].

While seated with eyes closed keeping the neck and back as straight as possible, voluntarily regulated breathing techniques (pranayamas) were practiced where the nostrils were manipulated by adopting a specific hand gesture (mudra) where the index finger and middle fingers were flexed against the palm keeping the thumb and other fingers extended. The ring and little finger were used to regulate the breathing through the left nostril while the thumb was similarly used for the right nostril.

For right nostril yoga breathing (surya anuloma viloma) and left nostril yoga breathing (chandra anuloma viloma) inhalation and exhalation were exclusively through the right and the left nostril respectively. These were practiced for nine rounds each. During alternate nostril breathing (nadishudhi) the practice began with exhalation through the left nostril, inhalation through the same side followed by exhalation and then inhalation on the right side. This was considered as one round and practiced for nine rounds. Bumble bee practice (brahmari) involved exhalation with a humming sound with the mouth closed and the index fingers on either side in the ears. This practice was performed for five rounds. Guided relaxation involved lying in the corpse posture (shavasana) and relaxing parts of the body beginning with the toes and moving upwards according to instructions.

These techniques were selected either because previous research showed that they reduced physiologic arousal (9,10) or based on our unpublished, clinical observations.

Yoga practice has also been shown to decrease the time taken to fall asleep, increase the total number of hours slept and the feeling of being rested in the morning, in older persons (13). Improved sleep efficiency, total sleep time, decreased sleep onset latency and reduced wake time after sleep onset in persons with chronic insomnia were reported following yoga practice (14).

A decrease in heart rate and breath rate following yoga training has been reported in normal volunteers (15) and in those who have increased psycho-physiological arousal due to their social circumstances, namely. adolescent girls in a remand home (16). The breath rate reduced following 3 weeks of yoga in children with impaired vision (17). The decrease in breath rate in the present study following yoga may be associated with a decrease in psycho-physiologic arousal (18) though no correlation was found between these variables and the self rated fear and anxiety.

The present results suggest the use of yoga to reduce stress and derive psycho-physiological benefits in survivors of a major natural disaster. However, given the fact that the study was conducted in a field setting it was not possible to have conventional controls, which is a definite limitation of the study.

The study formed part of a project funded by the Government of the Andaman and Nicobar Islands and the Government of Karnataka, India which is gratefully acknowledged.