\'Green\' yoga teachers could kill

Over-eager \"green\" teachers are leading beginners to perform certain relatively advanced poses that can trigger lethal strokes if executed incorrectly. Exercises like the plough and shoulder stand require participants to \"crank your head around a lot\", which could result in the linings of arteries running through the spine in the neck to be torn, according to William J. Broad, a Pulitzer Prize-winning science author. Blood clots can then form, which can cause ischeamic stroke if they become lodged in the brain. Mr Broad and a long-time yogi, discovered the dangers while researching his new book, The Science of Yoga: The Risks and Rewards. He said that while yoga was of tremendous benefit to many people, able to improve sex lives and even lengthen life, it did carry certain risks. He told BBC Radio 4\'s Today programme: \"I have been doing yoga since 1970 and I love it. It has been a great thing in my life. \"But as I pursued my research I discovered to my horror that there are some poses, which have a very low risk of happening, but if they do, have extremely high consequences.\" He went on: \"The number one danger in my book has to do with the neck. \"If you twist your neck around a lot there are these kind of fragile arteries that go through the vertabrae, called the vertrebral arteries, and their linings can get torn and produce clots. \"And if those clots go into your brain you can have a stroke.\" The book itself cites three examples from the medical literature of strokes caused by what he described as exercises involving \"extreme bending of the neck\". But Mr Broad emphasised: \"This is not anecdotal and it is not freak accidents.\" He said there was \"clinical report after clinical report after clinical report with yoga practitioners suffering these kind of strokes\", of which one in 20 was fatal. Both the plough and the shoulder stand are \'inversions\', involving lying on one\'s back and bringing the legs, almost straight, over the head to the floor to create an A shape. Mr Broad said these exercises were taught at \"many beginner classes\" even though they tended to be for the more advanced. He continued: \"The real dangers are these green teachers, who don\'t have the experience, who don\'t have the eye, who think everybody\'s as flexible as they are and they should all be looking like these models on the front of a glossy magazine. And that\'s wrong. \"We all have these different limitations and capabilities and smart teachers who\'ve been around for a while realise that.\" Pierre Bibby, chief executive of the British Wheel of Yoga, accepted there was a problem with underqualified teachers. There is no legal duty to be registered or trained, he noted. He said many people liked the idea of being a yoga teacher because it offered an \"alternative lifestyle\", but he warned in reality it paid \"pin money\". People should ask their teacher what training they had and where they qualified, he said, pointing out that the Wheel demanded 500 hours of training before deciding whether or not to give a qualification. He also remained unconvinced yoga caused many strokes, saying he had never heard of it happening in Britain. \"I\'m sure there is empirical evidence that he has based his book on,\" he said. \"But it\'s a question of quantifying it, isn\'t it?\" A spokesman for the Stroke Association said researchers there had never heard of a case of yoga causing a stroke. From The telegraph