If you inhale fully and then wait 10 seconds, you will be able to inhale a bit more, Holding your breath increases the pressure inside the lungs and gives them time to fully expand, increasing their capacity. As a result, the blood that then travels to the heart, brain, and muscles will be more oxygenated.
Inhale, inflating the lungs as fully as possible. Hold the breath for 10 seconds. After 10 seconds, inhale a little more. Then hold it for as long as you can. One caveat: For anxious people, breath retention can be difficult. Strom suggests starting with holding the breath for 3 seconds, or as long as feels comfortable, and working your way up.