I look at Yoga exercises as like stretching exercises to get one's blood flowing. Fans of alternative exercising & alternative medicines may want to take a look at the second Practical Lessons in Yoga e-book Freebie. The Practical Lessons in Yoga e-book boasts basic explanations & methods of the Yoga exercise. Some extreme practices of Yoga can be seen in India where the practice of Yoga had originated. Advanced Yoga practitioners stay in Yoga positions for hour, days or even months on end trying for reasons like to find peace within themselves & etc.