Effect of transcendental meditation on breathing and respiratory control

Abstract

We studied the effect of transcendental meditation (TM) on breathing using 16 experienced meditators and 16 control subjects. In controls, there was no significant difference in minute ventilation (VE), respiratory pattern, or hypercapnic response, whether breathing with eyes open-awake (CA), or with eyes closed-relaxing (CR). In meditators, VE decreased significantly during quiet breathing from 14.0 +/- 0.7 1/min with eyes open-awake (MA) to 12.4 +/- 0.6 1/min during meditation (MM) (P less than 0.02). The change in VE during meditation was due to a decrease in tidal volume (VT) resulting from a shortened inspiratory time (TI). Meditation was associated with a decreased response to progressive hypercapnia from 3.7 +/- 0.4 to 2.5 +/- 0.21 X min-1 X Torr-1 during MA and MM trials, respectively (P less than 0.01). During meditation VT was smaller at a given alveolar PCO2 than during MA studies because of a decrease in mean inspiratory flow rate (VT/TI). These observations suggest that an alteration in wakefulness, more subtle than sleep or the unconscious state, can significantly affect the chemical and neural regulation of breathing.

Cardiorespiratory and Metabolic Changes during Yoga Sessions: The Effects of Respiratory Exercises and Meditation Practices

“…As it can be observed in Table 1, the data in the present study corroborate the ones found in literature as they emphasize the occurrence of a hypometabolic state during meditation (Wallace 1970;Wolkove et al 1984;Young and Taylor 1998;Dusek et al 2005;Jevning et al 1992). However, since we aimed at assessing the cardiorespiratory and metabolic changes that took place during the same yoga session, we chose to reproduce the sequence of exercises proposed for one traditional hatha-yoga class (pranayamas followed by meditation).…”

“…In contrast, the control group presented a greater chemosensitivity to respiratory stimuli generated by hypercapnia (Wolkove et al 1984).…”

Coordination of Breathing with Nonrespiratory Activities

“…Regulated deep breathing with an emphasis on slow controlled expiration plays a role in yoga exercises. Depending on whether the yoga or meditation emphasizes relaxation or deep breathing exercises, the metabolic rate and respiratory frequency may go down, and the sensitivity to inhaled CO 2 may decrease (294). On the other hand, breathing exercises may represent a significant increase in metabolic demand, and in this setting oxygen consumption may actually increase even when the breathing occurs in the context of a meditative and relaxing regimen (269).…”

Long-term meditation is associated with increased gray matter density in the brain stem

“…As attention to breathing is a common element in meditation training in many traditions [8], and as meditation is known to have lasting effects on respiration control [9] and respiration rate, skin conductance, and oxygen consumption are all reduced [10], it is plausible that the long-term practice of such forms of meditation might induce structural changes in brain regions involved in basic autonomic regulation as suggested earlier [8,11].…”