I just read this article in Yoga Journal that basically said that yoga as we know it today with asanas and a certain focus on physical health is fairly new and dates back to the beginning of the 20th century. That it is also influenced by lots of other tradtitions, like indian wrestling and that it has some influences coming from outside of India even.
This coincides with a global rise in interest for physical health and at the same time, in India, the rising of the nationalist movement to break free from thebritish. So there was a need for an indian version of physical training.
I have no proof of this, I just read the article and I don’t want to offend anyone, but I find this very interesting and it doesn’t sound that far fetched since at least three major yoga schools can be traced back to the same guy (Krishnamacharya), who if I’m correct completely revolutionalized the practice and teaching of yoga.