Hatha Yoga is a branch of yoga. The word haṭha literally means "force" and thus alludes to a system of physical techniques. Hatha yoga is associated with the DashanamiSampradaya and the mystical figure of Dattatreya. In the 20th century, hatha yoga, particularly asanas (the physical postures), became popular throughout the world as a form of physical exercise, and is now colloquially termed as simply "yoga". The Hatha pradīpikạ was composed by Svātmārāma in the 15th century CE as a compilation of the earlier hatha yoga texts.
The Hatha Yoga Pradipika and the Gherandasamhita are derived from older Sanskrit texts. In Hatha Yoga Pradipika, Swatmarama introduces his system as preparatory stage for physical purification that the body practices for higher meditation or Yoga. It is based on asanas (postures) and pranayama (breathing techniques).
Hatha Yoga Pradipika lists 35 great Hatha Yoga siddhas or masters; AdiNatha, Matsyendranath and Gorakshanath. It includes information about shatkarma (purification), asana (postures), pranayama (subtle energy control), chakras (centers of energy), kundalini (instinct), bandhas (muscle force), kriyas (techniques; manifestations of kundalini), shakti (sacred force), nadis (channels), and mudras (symbolic gestures) among other topics.
Yoga's combined focus on mindfulness, breathing and physical movements brings health benefits with regular participation. Yoga participants report better sleep, increased energy levels and muscle tone, relief from muscle pain and stiffness, improved circulation and overall better general health. The breathing aspect of yoga can benefit heart rate and blood pressure.
The 2012 "Yoga in America" survey, conducted by Harris Interactive on behalf of Yoga Journal, shows that the number of adult practitioners in the US is 20.4 million, or 8.7 percent. The survey reported that 44 percent of those not practicing yoga said they are interested in trying it.