When you inhale, your heart rate rises slightly. When you exhale it falls slightly. There are probably evolutionary reasons for this (possibly to do with the ‘diver’s breath’ mammals take in water), but Yoga practitioners have long exploited this knowledge to create the so-called ‘meditative mind’, a deeply relaxed state of consciousness that allows thoughts to connect and synthesise in creative ways, giving ‘insight wisdom’, or, in Zen terms, seeing things as they are.
The slow down of the heart rate is associated, in obvious and less obvious ways, with relaxation, a kind of ‘rest and restore’ phase in the cycle, and something that has a ‘positive feedback’ effect. When you’re relaxed, your system’s inclined to respond to the condition of being relaxed by engaging in more restorative activity. Since consciousness is directly correlated to brain activity, this, in turn, has an effect on how you perceive the world, and yourself. You can attain a state of deep relaxation while still being thoroughly engaged with everything that is going on, in and around you. This can allow you to develop much more fruitful relationships, as you find yourself adopting a calmer, more compassionate understanding of situations.
However, there are significant side benefits quite apart from the ‘meditative mind’ that are associated with controlling, or lengthening, the breath, and particularly with making sure that your exhalation is longer than your inhalation (experienced practitioners and athletes can cope with a 2:1 ratio, but this takes practice).
A consistently raised heart rate is associated (though not directly correlated) with high blood pressure. If your blood pressure is high for an extensive period of time, you’re at risk of heart disease, stroke, kidney disease, dementia, and other serious health problems. Using the very simple formulation of breathing out for longer than you breathe in can induce a slower heart rate which, in turn, can reduce blood pressure. Because the effect isn’t direct, and because there are other things involved, you shouldn’t assume that this is the answer to all your problems. Changing the rhythm of your breathing with conscious awareness is a kind of ‘top down’ approach, whereas being in an unstressful or relaxing environment is a kind of ‘bottom up’, or organic, approach, and probably has deeper effects. Yoga uses both. But you can’t always magic yourself off to a beach in Tahiti, or even go and lie down on Yoga mat. And it’s definitely more worthwhile getting a small beneficial effect from this exercise than it is to slump back fatefully and succumb to an adverse health condition.
Sit up tall, as tall as you can without straining. Have an awareness of moving towards a more upright posture, rather than holding yourself rigid. Take your palms to your belly, thumbs on the navel, fingers spread, and begin to feel the breath moving in and out. You should feel your belly moving into your hands as you inhale, and back towards your spine as you exhale. If this doesn’t happen naturally, see if you can create the movement deliberately. Some people find this tricky, but it will come, with practice. Don’t stop using your rib-cage which also expands and contracts as you breathe. Just be more focused on your belly. Finally, begin to allow the exhalation to lengthen and deepen. Let yourself become more and more conscious of how many associated responses there are to this lengthened, relaxed exhalation.
You can then introduce the practice of counting as you breathe. You could count up to four as you inhale (1234) and down from four (4321) and then up to four (1234) making a total count of eight on the exhalation. If this is too much to begin with, just add one more count to the exhalation until you are comfortable with that, and then add another, and another, week by week.
Five minutes a day is a good start. You might want to build up to longer sessions but it’s more important (isn’t this almost always the case?) to make this a habit than it is to do the occasional marathon session.