1.67. Success (siddhi) comes to him who is engaged in the practice. How can one get success without practice; for by merely reading books on Yoga, one can never get success.
1.68. Success cannot be attained by adopting a particular yogic dress (Vesa). It cannot be gained by telling tales. Practice alone is the means to success. This is true, there is no doubt.
Yogin Svatmarama "Hatha Yoga Pradipika", 14 century