I can tell you how I experienced it. I did Astanga yoga (also refered to as power yoga) for many years. Such a class would consist of some 10 - 20 students and

I can tell you how I experienced it. I did Astanga yoga (also refered to as power yoga) for many years. Such a class would consist of some 10 - 20 students and 1 - 2 instructors. In this form of yoga at no time do you close you eyes (expect for the final relaxation time). Contrary to what you might think this particular form of yoga is very very psychically hard. Although you move slowly you are never still in a relaxed position. You move a lot of small muscles and carry your own weight for 1.5 - 2 hours. The concentration needed takes all your focus until you know the series of movement of the back of your hand. For me this took about a year. After this I would occasionally slip into a kind of mindlessness. I would "come back" and be conscience about this mindlessness at some point near the end of the session. It very much felt like 1.5 hours had passed in an instance. I would not be able to recall any detail or anything the instructors have said and I would feel immensely relaxed and full of energy. It was a great sensation. I suspect this has something to do with how you breath during yoga. It kind of resembles the way you breath when you are deep at sleep. It takes a long time to learn and I have a feeling that the breathing is actually the most important part of yoga. Besides swimming this is by far the best workout I have ever done. Being a programmer it does wonders for a body which spends most of the time sitting down in an office chair. If you get the chance I recommend that you try it out. You will be very surprised how hard it is - and how rewarding it is.