The long kumbhak group (Table II) showed a significant decrease (19%) in oxygen consumption during the pranayamic practice period from that of pre-pranayamic control value (paired ‘t’ test; P< 0.05). Out of the total amount of oxygen consumed in the entire experimental session, 29.4 per cent only was consumed during the pranayamic period in contrast to 36.3 per cent in the pre- pranayamic period, this difference was significant (paired ‘t’; test, P < 0.05). ANOVA (Table III) showed that the treatments effect was significant (P< 0.03; F 5.8, df 2.8). If it is assumed that the respiratory quotient (RQ) is 0.82 and the kcal / 1 oxygen is 4.825, application of the DuBois formula indicates that the metabolic rate in the short kumbhak type of pranayamic breathing period will be +70 per cent higher than that of the pre-pranayamic base-line breathing, in contrast to the reduction by -20 per cent in the long kumbhak type of pranayamic breathing. Since a variation of RQ between 0.71 and 1.0 contributes to not more than a maximum of 6 per cent error, the above derivations of metabolic rate are reliable enough to understand the effect of Pranayama. There was no significant difference between the two groups (Student’s ‘t’ test) in the base-line pre- pranayamic pulmonary ventilation (Table 1), or in the base-line oxygen consumption values (Table II). There was a difference (Student’s ‘t’ test) only in the base-line respiratory rate, the short kumbhak group having 13.1 ± 2.5/ min and the long kumbhak group having 7.9 ± 1.61 /min. During pranayama the respiratory rate was lowered to 24.42 and 27.84 per cent in the short and long kumbhak types, respectively; the corresponding pulmonary ventilatory values were 48 and 46.6 per cent. During post-pranayamic period, pulmonary ventilation was restored to pre- pranayamic levels in both groups. During both short and long kumbhak types of pranayamic breathing periods, the pulmonary ventilation (Table I) was lower than in the pre-pranayamic breathing periods (control values), but interestingly the oxygen consumption (Table II) significantly (paired ‘t’ test) exceeded the pre- pranayamic control value in one type of pranayama (SK type), whereas it decreased significantly in the other type of pranayama (LK type). Thus the oxygen consumption was not correlated to ventilation, but the duration of kumbhak phase on the other hand, seems to play a major role. |