When Science Measured What Breathing Can Do

How a Randomized Experiment at L&T — with Blood Tests, Peer Reviews, and a One-Year Follow-Up — Proved That Breathing Techniques Change More Than Feelings

Most corporate wellness programs are evaluated with feedback forms. Participants tick boxes. They say they feel better. Everyone moves on.

This study did something different. It drew blood.

Researchers Zubin R. Mulla from the Tata Institute of Social Sciences (TISS), Mumbai, and Vedamuthachar A. from the National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, designed a randomized wait-list control field experiment to test the Art of Living's APEX program. Not with opinion surveys alone — but with blood serum cortisol measurements, heart rate variability monitoring, peer-reported emotional intelligence assessments, and a one-year follow-up survey.

The experiment was conducted at Larsen & Toubro Limited's headquarters in Mumbai. L&T sponsored the study, provided full logistical support, and assigned research associates from within the company. This was not an arm's-length endorsement. L&T put its own people and resources into finding out whether the program actually worked.

80 L&T executives volunteered. Of these, 72 completed the full experiment — 37 in the experimental group, 35 in the control group. Participants ranged from 22 to 65 years of age, with a median age of 31. Smokers, caffeine addicts, and alcohol addicts were screened out before enrollment. The two groups were formed by random assignment.

The design was a wait-list control: the experimental group did the APEX program in April 2011, while the control group waited three months and did the same program in July 2011. Both groups were measured at three points — April, July, and October 2011. This meant the researchers could compare the experimental group's change against a control group that had not yet received the intervention, and then verify whether the control group showed similar changes once they did receive it.

The variables measured were not vague. On the psychological side: stress (using a validated single-item scale), life satisfaction (using the established 5-item Satisfaction with Life Scale), emotional stability (self-reported), and emotional intelligence (reported not by the participants themselves, but by their office colleagues — their "office confidants"). On the physiological side: blood serum cortisol levels, drawn between 8:30 and 9:30 AM, and heart rate variability measured through continuous ECG monitoring.

The results were statistically significant and consistent.

For the experimental group, stress dropped significantly between April and July 2011 (p = .00) and remained low through October. Life satisfaction increased. Emotional stability increased significantly (p = .02) and held steady. Office confidants — the colleagues who worked alongside these participants every day — reported that participants' regulation of emotions had improved.

The physiological data backed this up. Blood serum cortisol — the hormone directly produced by the body under stress — showed significant reduction for the experimental group between April and July, and continued to reduce between July and October. The researchers attributed the continued drop to sustained practice of the Sudarshan Kriya technique learned in the program.

The control group showed the same pattern once they went through the APEX program in July: significant reductions in stress, increases in life satisfaction, and improved emotional stability between July and October.

The cortisol numbers tell the story most precisely. The experimental group's mean cortisol went from 14.65 µg/dl in April to 11.27 µg/dl in July (p = .00) to 9.23 µg/dl in October (p = .00). That is a 37% reduction in the stress hormone over six months. The control group showed no significant cortisol change during the waiting period (April to July), but once they did the program, their cortisol dropped significantly from 12.56 to 9.96 µg/dl (p = .00).

Heart rate variability showed no significant changes in either group — the researchers reported this transparently, as a rigorous study should.

A year after the program, in July 2012, the researchers went back. They sent questionnaires to all 72 participants. 62 responded — an 86% response rate.

Of those, 13 were still practicing Sudarshan Kriya every day. 13 more practiced once a week. 16 practiced once a month. 20 had stopped after the initial few months.

The findings were clear: the effects of the program were sustainable over a year, especially for those who continued practicing. Participants reported feeling more calm, less angry, more focused, and a general sense of well-being. Some reported that physical ailments — acidity, back pain, eyestrain, recurring colds — had been resolved. One participant reported quitting smoking. On the professional side, participants noted less anxiety about new projects, better concentration, reduced fatigue, better control of emotions, and improved prioritization of tasks.

The researchers themselves noted what makes this study unusual.

First, it was a field experiment in a real organisational setting — not a lab study with students. Second, it measured both physiological and psychological outcomes simultaneously, providing what the paper calls "a holistic perspective on the likely positive effects." Third, the psychological outcomes were not just self-reported. The emotional intelligence measures came from office peers — people who had no stake in the program's success but could observe the participants' behaviour changes in daily work. As the paper states: "not only do participants feel that they have more emotional stability as a result of the SMI, but their office colleagues are able to notice it as well."

And finally, the one-year follow-up confirmed that the benefits held — turning this from a study about a short-term intervention into evidence for a lasting change.

The study was honest about its limitations. The sample was small — 72 participants. The control group showed some unexpected improvements even before receiving the intervention, likely due to what researchers call "demand characteristics" — the tendency to respond favourably when enrolled in an experiment. Heart rate variability showed no significant changes. These are reported openly in the paper.

But the core findings are hard to argue with. A randomized controlled experiment. Blood cortisol measurements showing a 37% drop. Peer-verified improvements in emotional regulation. Self-reported reductions in stress that held up at six months. A one-year follow-up confirming sustained benefits. Published by researchers from TISS and NIMHANS — two of India's most respected institutions for social science and neuroscience research.

This is not a testimonial. This is not a feedback form. This is science, conducted in a corporate setting, measuring what happens inside the body and the mind when people learn to breathe differently. And the answer, backed by blood tests and peer reports and a year of follow-up data, is that it works.

This study was conducted by Zubin R. Mulla (TISS, Mumbai) and Vedamuthachar A. (NIMHANS, Bangalore), with research associates Rohan Athalye and Rajashree Chakraborty from L&T. Research concept and coordination: Neville Lobo (L&T) and Ramesh Raman (APEX). Data collection: Monica Shah (L&T), Deepa Iyer, Barkha Goyal, Uma Ramesh, and Bharti Vankadari (APEX). Special thanks to Larsen & Toubro Limited for sponsoring and conducting the field experiment.