A FEW SCIENTIFIC STUDIES ON YOGIS

A frequent claim is that some yogis are able to survive long periods of time in a meditative state without food, water, or even air. Several studies have examined the hypothesis that they do this by lowering their metabolism, one indication of which would be a decrease in heart rate and hence in oxygen consumption. …

A much more extreme case, observed and reported by Kothari, Bordia, and Gupta, involved a yogi who was confined to a small underground pit for eight days, connected to an EKG with 12 leads “short enough not to allow any movement”. Almost immediately after the pit was sealed, a significant sinus tachycardia developed and progressed until it reached 250 beats per minute, but without any sign of ischemia. This tachycardia continued for 29 hours when, suddenly and with no prior slowing of the heart rate, “a straight-line had replaced the [EKG] tracing”. The investigators wanted to terminate the experiment, understandably fearing that the yogi was dead, but his attendants insisted that it continue. The flat-line state persisted for five more days until, half an hour before the experiment was scheduled to end, sinus tachycardia again developed. This continued for two hours after the yogi was removed from the pit, when his heart rate finally returned to normal (98 beats per minute). The obvious explanation, that the EKG leads had been disconnected, was ruled out, first because the machine was immediately checked for any malfunctioning, but more importantly because no electrical disturbance ever appeared, such as would accompany the disconnection of the leads; subsequent attempts by the investigators to disconnect the leads always produced “gross and irregular electrical disturbance.” … Having ruled out such explanations, the authors candidly admitted that they were “not prepared” to accept that the yogi had voluntarily stopped his heart for five days and survived; but they could “offer no satisfactory explanation for the [EKG] record before us”. Others studies have also involved putting yogis in underground pits, for periods ranging from hours to days, and observing metabolic changes including oxygen intake and carbon dioxide output. Most have shown a significant decrease in oxygen consumption, “much more than what could be produced even by sleep”…

Similarly, a yogi was reportedly able to induce an 11º F difference in the temperature of the left and right sides of the palm of one hand, with the color of the skin changing to pink on the hot side and grey on the cold side. … Similarly, Benson et al. found that three practitioners of gTum-mo (or heat) yoga, who also learn to warm themselves while meditating in cold Himalayan mountain conditions, could deliberately and significantly raise the temperature of their fingers and toes, by amounts ranging from 3.15º C up to 8.3º C. Body temperature can apparently also be lowered. For example, the yogi studied by Kothari et al., who had such extreme and deliberately produced fluctuations in heart rate, including a straight-line EKG for five days, had also induced a marked hypothermia. The investigators reported that his body temperature was “abnormally cold” (34.8 degree C/ 94.6 degree F) when he was removed from the pit, and he shivered severely for two hours afterward, although the temperature in the pit had been normal and comfortable (24-33º C) for the entire eight days.

From the book IRREDUCIBLE MIND: TOWARD A PSYCHOLOGY FOR THE 21ST CENTURY by Edward F. Kelly et al., Rowman & Littlefield, 2010, pp. 177-179.