Yog is a lifestyle with yama and niyama as its foundations. It teaches us nonviolence, control over our body mind and senses, inner and outer purity and lot more including staying in bliss without any attachment but I am saddened to see the changed definition of YOG and YOG TEACHERS.
I can't understand those who themselves are addicted to so many kinds of drinks and heavy foods declare themselves as Yog teachers. 
Let this great science not become just a physical exercise for sake of few coins. My humble request. Om