Yoga may help kids on different levels. Practicing physical postures (asanas) can increase the production of endorphins, which generate feelings of well-being. Breathing techniques (pranayama) help regulate the nervous system by activating parasympathetic (relaxation) neurons and calming sympathetic (flight or fight) neurons. Guided relaxation techniques benefit kids by giving them an alternative way to respond to the stressors in their lives.
Yoga and India aren't strangers, yet we find Yoga's popularity suddenly spiking after it's embraced by the west. It has become the thing to do to be fit with celebrities swearing by it. It is as if Yoga is a 'novel' concept or is reinvented by the west. After it has become the 'in' thing, there are two sets of people- the ones who do it and others who don't. Most of people who do it, adopt yoga for life while the others don't want to do it because of the myths around it or don't know how.