Traditionally the physical branch of yoga was practiced with the recitation of certain mantras while doing certain poses such as Surya Namaskar. As this branch of yoga was spread throughout the West, emphasis has been placed on solely the physical postures and movements. These movements and postures have tremendous health benefits which are medically supported and have often successfully treated a myriad of health issues. So the postures and movements are just that. There’s nothing demonic about the postures and movements themselves. In yogic tradition these are used simply to properly regulate and enhance the functions of the body so that it is more conducive to being synchronized with one’s mind and spirit. Again, yoga means “union” in Sanskrit. That’s the purpose of yoga. You may find it helpful to recite a Latin prayer of choosing while doing Yoga. Personally, it’s a dream of mine to have the Catholic prayers translated into Sanskrit because one of the reasons the Vedic mantras are recited in Sanskrit is because the auditory value that the language has. The sound vibrations derived from reciting Sanskrit have a significant effect on the human person, and can be used both negatively and positively but nonetheless powerful.