[amrx101]

Whatever I am saying I have no "scientific proof" but I come from a traditional family of meditators. We have history of monks and sanyasis in my family who in their prime youth just went to jungle and meditated and died their just sitting. If you come to east India, you will find many small shrines built at places where my ancestors died.

Whatever @nsouth has said is correct. What Westerners call Yoga are actually Asanas. What I want to add is a warning that is passed in my family from generation to generation. If you are a materialistic and sexual person dont try to do exercises that will arisen the Kundalini. If you are are materialistic and sexual Raja Yoga is not for you. Have a good life(marry, earn and be a force of good in society(what we would traditionally call Dharma)), you can definitely do Asanas and even meditation but you should never ever start a practise that specifically targets Kundalini. In breathing exercise, you can do all breathing exercises sans the retention part. I have no proof or logic behind this warning but I just stated what has been stated in my family for ages.