Doctor Weil writes: “This breathing exercise is a natural tranquillizer for the nervous system. Unlike tranquillizing drugs, which are often effective when you first take them but then lose their power over time, this exercise is subtle when you first try it, but gains in power with repetition and practice.
“Do it at least twice a day. You cannot do it too frequently. Do not do more than four breaths at one time for the first month of practice.”
Researchers have tested the method in a clinical setting. One study, published this summer in the peer-reviewed, trusted journal Physiology Reports, looked at how 22 sleep-deprived adults reacted to the method.
It was spotted that after doing the method, the participants had lower resting heart rates as well as systolic blood pressure.