In the yoga tradition, the technique of Stimulating Breath, or Bellows Breath is used to raise energy and increase alertness. This simple breathing technique may just replace your afternoon cup of coffee. It works, but practicing this exercise is noisy. You may not want to use this method to stay awake during a boring meeting!

How to practice Stimulating Breath:
Inhale and exhale rapidly through the nose. Keep the mouth closed and relaxed. Maintain breaths in and out that are equal in duration and as short as possible.

Try for three in-and-out breath cycles per second. The diaphragm moves up and down quickly, in the same manner as a bellows.
Breathe normally after each cycle.

Do not do for more than 15 seconds on your first try. Each time you practice the Stimulating Breath, you can increase your time by five seconds or so, until you reach a full minute.

If done properly, this technique can invigorate you like a good workout. You may feel the effort at the back of the neck, the diaphragm, the chest and the abdomen. As with all breathing exercises, practice safely and use common sense and moderation.