Yoga not enjoined by Scriptures
The Ashtanga Yoga primary series of poses would seem like a never ending ordeal especially for a new practitioner. Just when one would start to feel that the poses in the sequences had gotten easier there would come a grueling pose that would break the reverie. The last pose in the Ashtanga yoga primary series (after the so called 'cooling down' poses) is a pose called Uthpluthihi. It is an arm balance with the legs crosssed in padmasana. It is considered a difficult pose to hold, yet considered an important pose because it builds core strength and it also exercises the internal organs in the abdominal region through this core action which is exercised using the Uddhiana and Moola Bandhas. Due to these benefits, some yoga teachers will require their students to hold this pose for a full minute, which is not an easy task, even for an advanced student.
Some teachers take the pleasure of teasing their students, or tormenting them (to be more accurate), when they are holding this pose, by elongating the count when the count reaches nine, when the students would already be huffing and puffing and beginning to hold their breath. Does this sound familiar ..,7,8,9,9½,9¾,......,(and finally after a long pause) 10 ?
Jokes and teasing aside, forms of yoga like bikram yoga, hot yoga, power yoga and ashtanga yoga are sometimes taught and practiced in ways that are "un-yogic". The insidious aspect about some of these schools of yoga is that it is taught by some teachers under the cloak of ancient tradition, out of complete ignorance of the many scriptural aspects of yoga. The Vasanas (literally means smell or metaphorically the energy exuded) of this kind of harsh practice attracts similar minded people who are willing to go to great lengths to punish their bodies (and that of their students once they become teachers) and sculpt muscles.
For these reasons, these schools are perceived in poor light by many. Some well respected researchers on yoga, like Alistair Shearer, the author of "The story of Yoga" have used the words "Spandex body building" to describe these practices.
There are two great scriptural texts on yoga. One is the Yoga Sutras of Patanjali and the other is The Bhagavad Gita. The Bhagavad Gita (17.5-17.6) clearly outlines what is considered a demonic form of austerity (yogic practice) :
Senselessly torturing all the elements in the body, and Me also who dwells within the body — you may know these to be of demoniacal resolves.
Lord Krishna tells Arjuna that those who subject their bodies to such harsh austerities, not only torture their bodies, but also him, who resides in every being.
The fine line between ecstacy and torment
There is a fine line between ecstacy and torment in asana practice. When practiced with the intention of tuning into the Prana, one finds ecstacy. When practiced with the intention of body building, one loses association with the prana flowing in the body; this results in torture.
Guruji Pattabhi Jois when asked the purpose of each series of ashtanga yoga , would say, that the primary series mainly serves as "Yoga Chikitsa", treatment of the body; the secondary series' main purpose is "Nadi Shodhana", cleansing of the Nadis; he would then, when prodded about the benefit of the advanced series, say, jokingly, that the advanced asanas are used mainly for demonstration.