Answering an email or text may seem simple enough, but sometimes this simple act can elicit a seemingly dramatic bodily response: you may find yourself holding your breath or breathing shallowly.

When a person holds their breath, the body immediately begins to adapt to the lack of oxygen and the build-up of carbon dioxide. These adjustments involve slowing the heart rate, redirecting blood ...

If you could patent and sell the idea of holding your breath before exercise to boost performance, it would be a bestseller. Not because it works, necessarily—the jury is still out on that. But ...