Not Convinced That Yoga Has Absolutely Amazing Health Benefits? Then Read:

Ancient Secret of the Fountain of Youth: Book 1 by: Peter Kelder:
http://www.amazon.com/Ancient-Secret-Fountain-Youth-Book/dp/038549162X

Ancient Secret of the Fountain of Youth: Book 2 by: Peter Kelder:
http://www.amazon.com/Ancient-Secret-Fountain-Youth-Book/dp/0385491670

Bikram's Beginning Yoga Class by Bikram Choudhury:
http://www.amazon.com/exec/obidos/ASIN/1585420204

Power Yoga: The Total Strength and Flexibility Workout by Beryl Bender Birch:
http://www.amazon.com/exec/obidos/ASIN/0020583516