The powerful breathing completely cleanses your blood, flushing out toxins and the waste products of metabolism. You may feel like you're hyperventilating, and that's absolutely fine! In fact, it's great and - AS LONG AS YOU DON'T DO IT DIRECTLY BEFORE A DIVE - hyperventilation is a powerful way to increase your lung capacity and strengthen your lung tissue. Not to mention it gives you a completely natural and free high! So enjoy it!