Can you fit your self in 1m Jar? If yes, you will get honor of become third man in the world to do that. Colombian born Miguel Santa-Ruiz is one of them, working for Circus Royale.
Miguel is working in circus for 42 years and performing this act since age of 22 years. Daily two hours of exercise and Yoga enable him to do this act. Generally he performs five times a day, but it is little hard in cold weather according to him.
Do not try this at home. It requires lots of practice and experience.