Some info about Laughter Yoga:

         In 1995 Dr. Madan Kataria founded 'Laughter Yoga' clubs with just five people in a public park in Mumbai, and since then, has continued to expand to over 7,000 clubs in 70 countries. After exhaustive research, Dr Kataria concluded that laughter has significant physiological (e.g. endorphins), and psychological (mental Health) benefits. Laughter Yoga employs unique improvisational exercises that use no words, and yoga breathing. It has scientifically been shown to result in human health benefits, including transforming depression, reducing distress, burning calories, and decreasing respiratory infections.

         Laughter is a common universal behavior that anyone, young or old, can easily understand and experience.  Laughter is contagious, bringing together people from all walks of life, sharing monumental joy rarely experienced in today's world. Laughter breathing methodology therapeutically permits people to exhale specific laughter sounds releasing stale and negative thinking, and inhaling fun, wholesome behavior, playful laughter, and health. We typically generate fun, and invent creative exercises that normally stimulate laughter in people within three seconds.
World Laughter Day 2015