As you see the good results arising from adjusting the breath, you become more motivated to explore the potentials of the breath in a wide variety of different situations: when you’re sick, when you feel physically or emotionally threatened, when you need to tap into reserves of energy to overcome feelings of exhaustion.

"Playing with the breath also helps you stay in the present — and stick with the meditation over time — because it gives you something interesting and engaging to do that can show immediate benefits. This keeps you from getting bored with the meditation. As you see the good results arising from adjusting the breath, you become more motivated to explore the potentials of the breath in a wide variety of different situations: how to adjust the breath when you’re sick, how to adjust it when you feel physically or emotionally threatened, how to adjust it when you need to tap into reserves of energy to overcome feelings of exhaustion.

The pleasure and refreshment that can come from working and playing with the breath provide your ardency with a source of inner food. This inner food helps you deal with the obstreperous members of the committee of the mind who won’t back down unless they get immediate gratification. You learn that simply breathing in a particular way gives rise to an immediate sense of pleasure. You can relax patterns of tension in different parts of the body — the back of the hands, the feet, in your stomach or chest — that would otherwise trigger and feed unskillful urges. This alleviates the sense of inner hunger that can drive you to do things that you know aren’t skillful. So in addition to helping with your ardency, this way of working with the breath can help with your practice of virtue."

~ Thanissaro Bhikkhu "With Each & Every Breath: A Guide to Meditation"