To give a teachers training course in yoga, you must be a yogacharya (spiritual master of yoga), and to be yogacharya, you SHOULD have studied with a Yogacharya with recognized lineage, in gurukula tradition. The trainers of yoga teachers and master degree of yoga, give a teachers training course in yoga, but only under the guidance of a really guru or yogacharya (spiritual master of yoga). A real teacher is he, whom his guru or master has co-signed as a yogacharya. Because the guru has confirmed their samadhis. Yoga can have training programs, but these programs are useless if there is no yogacharya. A yoga teacher, yoga instructor, or even trainer of yoga teachers -Formateur. can not train in the absence in a course of one yogacharya. Yoga is samadhi, not asanas or techniques. But what is happening today in the world, is that the yoga courses are not trained yoga teachers, but teachers of yoga techniques. The teachers of yoga techniques, are not yoga teachers, but they all contribute to the spread of yoga. There is no contradiction between the two professions. Only complement and do not see anything objectionable in both.
Swami Maitreyananda, president of World Yoga Council IYF