NPR: Breathing is essential to life. And lately, the safety of the air we inhale, or the need to pause and take a deep breath, is on our minds a lot. This hour, TED speakers explore the power of breath.

So the average person of my size and shape, when they take a deep breath to exhale into that spirometer to do their lung capacity test, would kind of go like this (inhaling, exhaling). And that’s all they would get. Now, as a trained free diver and somebody who’s, you know, really trying to blow the lid off that spirometer, I would take a breath that sounds like this (inhaling, exhaling). And that’s called packing, and that is something that only experienced free divers should be doing because there are some inherent risks associated with it. But what it does for a free diver is it is a way of sucking more air volume into your lungs and expanding them as much as possible.