First, what is breath control? It is a conscious control of the breath. Essentially, it is controlling the inhale, hold, and exhale of the breath. It is dangerous you might ask? Well anything can be harmful if done without care and use of common sense. You should never go past you limits and should ease into the process. Never hold you breath to the point of passing out or make you exhale a hurried one due to straining yourself on the hold. Stop if you feel discomfort and continue the next day or until discomfort subsides. You must use your own common sense. The benefits far outweigh the negatives. Use of breath control will provide the cells with an abundance of energy! It will also increase your subtle sensitivity and bring the mind home(one-pointed and peaceful mood/mind). A good ratio to start out with is a inhale of 4 seconds, a hold of 16 seconds, and a exhale of 8 seconds. Do this about 18-36 reps. Inhale/Hold/Exhale = 1 rep. This breathing method will provide the body with energy and rhythm! If you do this before meditation, it will make the mind more relaxed and fit for the task! In summary, breath control is a great exercise to add to your everyday life and is not dangerous when you follow the basics I have laid out in this post. Peace and Love to you all!