Cyclic meditation (CM) is a technique which combines ‘stimulating’ and ‘calming’ practices, based on a statement in ancient yoga texts suggesting that such a combination may be especially helpful to reach a state of mental equilibrium. The oxygen consumption, breath rate and breath volume of 50 male volunteers (group mean age±SD, 27±6.3 years) were assessed before, during, and after sessions of CM and sessions of supine rest in the corpse posture (shavasana, SH). The sessions were one day apart and the order was alternated. The oxygen consumption, breath rate and breath volume increased during the ‘stimulating’ practices of CM, returned to the baseline during the ‘calming’ practices, and the oxygen consumption decreased by 19.3 percent below baseline values after CM. During the SH session the oxygen consumption, breath rate and breath volume reduced; however the decrease in oxygen consumption after SH was less than after CM (i.e., 4.8 percent). The results support the idea that a combination of yoga postures with supine rest (in CM) reduces the oxygen consumption more than resting supine alone does.

INTRODUCTION
Oxygen consumption is generally regarded as a reliable index of physical activity and arousal (Bonnet & Anand, 2003). Transcendental meditation (TM) has been extensively researched and based on a wide spectrum of physiological data it has been hypothesized that transcendental meditation is an integrated response with peripheral circulatory and metabolic changes (evidenced by a decrease in oxygen consumption) sub-serving increased central nervous activity (Jevning, Wallace, & Beidebach, 1992). Meditation on the Sanskrit syllableOMal so resulted in a decrease in oxygen consumption simultaneous with a decrease in cutaneous blood flow and a reduction in heart rate (Telles, Nagarathna, & Nagendra, 1998). Both TM and meditation on OM are practiced while seated and with eyes closed. Another meditation technique called cyclic meditation involves the practice of yoga postures interspersed with supine rest (Nagendra & Nagarathna, 1997). This technique was derived from an ancient Indian text, the Mandukya Upanisad (Chinmayananda, 1984). The technique was based on the belief that the combination (of yoga postures with supine rest) would facilitate reaching a relaxed state more easily than either practice alone. The practice of cyclic meditation was shown to decrease the oxygen consumption, breath rate and increase the breath volume to a greater degree than a comparable duration of supine rest, in forty volunteers (Telles, Reddy, & Nagendra, 2000). The magnitude of re- duction in oxygen consumption following cyclic meditation was 32.1 percent (as compared to 10.1 percent after supine rest). However the recordings were made using a closed circuit Benedict-Roth apparatus which has a number of practical disadvantages. For example, recordings were made before and after, but not during the practice. Also it is recognized that while breathing through the Benedict-Roth closed circuit apparatus some people find it hard to breathe normally (Judy, 1982). Another criticism of the method is that accuracy depends on the ability of a subject to breathe regularly. If the rate or amplitude (or both) of respiration are irregular it is difficult to decide precisely where to draw the sloping line which determines the oxygen consumption. In the closed circuit system, the person breathes from a reservoir of one hundred percent oxygen and the resistance offered by the apparatus to increase the volume of breathing required during physical activity is high so that the rate of carbon dioxide removal by absorption may be inadequate for accurate results during even moderate activity (American Association for Respiratory Care, 1994). It has also been shown that the resistance to breathing is increased, inspiratory time is prolonged and the work of breathing may be increased by as much as 10 percent in closed- circuit systems (Branson, 1990). Generally, the open-circuit system is regarded as more accurate since the person breathes ambient air and the apparatus does not offer resistance to the flow of air (Matarese, 1997). With this background the present study was planned to record the oxygen consumption (using an open circuit apparatus)before, during and after CM compared to an equal duration of shavasana (SH), (i) to understand the changes during the actual practice of CM and (ii) to compare the findings with the earlier study (cited above) which had an identical study design.