[In one study comparing brand-new yogis and seasoned walkers after 3 months], beginning [Iyengar] yogis experienced major rises in [GABA], … a neurotransmitter that tends to promote relaxation and reduce anxiety, along with improved moods and lessened anxiety …
better than the [effects observed in] the walkers.
Yoga Alliance endorses a category of training that requires … about 3 months … [but Iyengar] requires candidates for teacher training to have studied the style for a minimum of 3 years, and then trains them for a minimum of 2 years and administers [Introductory teacher] examinations … It is the Iyengar people who have redesigned some of yoga's most dangerous poses. Teacher training puts much emphasis on how to lessen the risks.
—The Science of Yoga: the risks and rewards, by William J Broad
[one of] the most suitable options for people with orthopedic and musculoskeletal problems… [The outcomes of] clinical trials … showed that a well-designed yoga program not only decreased the perceived intensity of back pain, but also improved people's ability to accomplish their daily tasks.
… to become an Iyengar instructor [requires] lengthy teacher-training programs… about 5 years before aspiring Iyengar teachers [are] allowed to call themselves instructors …[and] reaching junior instructor level [can] take a decade of work and testing. —Crooked: Outwitting the back pain industry and getting on the road
to recovery, by Cathryn Jakobson Ramin
Ramin [author of Crooked
, above], who suffered from chronic lower-back pain for years, credits her recovery to a series of "back whisperers". They include personal trainers, Iyengar yoga teachers … Iyengar yoga is 'a purely orthopaedic style of yoga'. —There's good news for sufferers of chronic lower-back pain, by Ruth Nichol in The Listener.