Breathe of fire is a basic kundalini breathing technique.
It is one of the first things I learned in a Kundalini class.
This type of breathing also helps to balance pH in the body, because it helps to expel excess acid.
If you want to learn more about the benefits of pH balance in the body check out the site, AlkalineHealth.net
This is one that can be practiced on a daily basis. It is great for boosting energy. Some people do this in place of a cup of coffee in the morning.
Be sure to expand the abdomen on the inhale and contract on the exhale.
If you start to lose it, slow it down. Practice makes perfect.
You should not feel light headed when doing this, if so slow it down, or take a break.
Hardarshan does a great job of teaching us this breathing technique.