Antigravity Inc. founder Christopher Harrison (C) sits in a hammock as he conducts a class of "antigravity" yoga class at the Om Factory in New York August 16, 2011. "Antigravity" yoga makes use of hammocks to help practitioners gain greater flexibility, allowing for a wider range of yoga poses, according to the workshop's website. [Photo/Agencies]

Student sit in hammocks as they take part in an "antigravity" yoga class at the Om Factory in New York August 16, 2011. "Antigravity" yoga makes use of hammocks to help practitioners gain greater flexibility, allowing for a wider range of yoga poses, according to the workshop's website.[Photo/Agencies]