Students take part in an "antigravity" yoga class at the Om Factory in New York on Aug 16, 2011. "Antigravity" yoga uses hammocks to help practitioners gain greater flexibility, allowing for a wider range of yoga poses, according to the workshop's website. [Photo/Agencies]

Students take part in an "antigravity" yoga class at the Om Factory in New York on Aug 16, 2011. [Photo/Agencies]

Yoga students hang like bats from the ceiling of a loft space in the heart of Manhattan's fashion district. In the Om Factory yoga studio, situated in a former garment factory, practitioners call it "antigravity" yoga.

The company website claims this combination of traditional yoga, aerial acrobatics, dance Pilates and calisthenics assists students realign their bodies. The hammocks allows students to hold and balance in difficult yoga poses longer, helping them gain better kinesthetic awareness. It also helps them build strength and become more flexible. Hanging upside down is also thought to help decompress the vertebrae.

Traditional yoga has many styles, which aim to help practitioners gain strength, flexibility, breath control, spiritual awareness and realignment of the body. Yoga teachers will often incorporate props to help students work their way into poses. One style uses a very hot room to add a different element to the practice. It is difficult to say how many people practice yoga but according to a BBC story in 2009, more than 30 million people practice it worldwide.

Antigravity Inc. founder Christopher Harrison (C) instructs students how to hang upside down in hammocks as they take part in an "antigravity" yoga class at the Om Factory in New York on Aug 16, 2011. [Photo/Agencies]