It is not as if Yoga Day has not run into controversy. Some Muslim and Christian organisations have demurred, saying that yoga - or, at any rate, specific chants or sequences like Surya-namaskar - have distinct Hindu overtones. In response, the government took Surya-namaskar out of the recommended routines - and some ministers and leaders have denied there is anything Hindu about yoga at all. This, typically, has offended yet others, who insist that yoga is indeed Hinduism's gift to the world, and this should be acknowledged and not avoided. Finally, there is Adityanath, the member of Parliament from Gorakhpur, who affects the title "yogi" and can always be relied on to provide proper perspective: people who objected to the Surya-namaskar, he said, should "leave Hindustan" and "drown themselves in the ocean or live in a darkened room for the rest of their lives". Certainly, it does appear that Mr Modi's decision to push Yoga Day is of a piece with his culture-warrior persona, the side of him that chooses to gift the Bhagavad Gita to foreign leaders on behalf of the nation - and then, without specific provocation, mocks "secularists" back home who might conceivably object. But, as the culture wars go, this is a relatively harmless skirmish. Certainly, anything that gets more Indians exercising cannot be seen as a very bad thing. The middle-class Indian lifestyle is unquestionably excessively sedentary.
That said, it is worth noting that the mass exercises planned are exactly the opposite of what makes yoga effective. Yoga works through adjusting to individual capacities, and through calming the mind. The latter is hardly likely in the middle of Rajpath, or in any one of the other mass exercises being planned. And mass-produced exercises, in which everyone is taught and does the same yoga asanas, are more than counter-productive: they can be dangerous. Yoga evolved to be taught one-on-one for a reason: it requires the student to be pushed to the limits of flexibility and endurance, but not too much further. Unlike with aerobic exercise, stretching-based activities like yoga and tai chi are not supposed to cause discomfort. But, as a much-read New York Times essay called 'How yoga can wreck your body' pointed out in 2012, there is a great danger in large, crowded classes that novices are pushed into positions that are dangerous for their muscles, bones and joints. Yes, yoga is calming, and an important part of Indian heritage. But mass yoga exercises are less about public health and more about the projection of soft power.