Hypnosis isn't just good for making people cluck like chickens. Since it was first explored by Sigmund Freud, the science hypnosis has expanded into many different areas. Everyone know you can be hypnotized to quit smoking, but Sarah Ferguson and the Duchess of York, former Spice Girl Geri Halliwell, and singer Lily Allen and "Newsroom" actress Olivia Munn, found that they could be hypnotized to like going to the gym.

The stars list hypnosis as the key to their workout motivation. Hypnosis is an extremely focused form of meditation that leaves the mind open to the power of suggestion.  Former Spice Girl Geri Halliwell, British singer Lily Allen and Olivia Munn credit hypnotism for helping them lose weight.

Munn told Good Housekeeping magazine she went to a hypnotist to help with her obsessive-compulsive disorder and trichotillomania (a hair-pulling disorder). She then started using hypnosis for fitness.

"I'm not exaggerating: That was on a Friday, and by Monday I was working out every day at 6am. If I missed a session, I'd double up and do it the next day," Munn told Good Housekeeping.

"After the hypnotism, I want to go to the gym every day, otherwise I feel really bad," Lily Allen told the Daily Mail.

New York City hypnotist Elena Beloff, who runs the interactive hypnosis site Hypnocloud, agrees. Beloff told the New York Post that she has changed lives through hypnosis.

"You are in a relaxed state. You can see yourself exercising and you can see yourself getting the benefits so your mind gets excited about it," Beloff told the New York Post.

Beloff recently motivated 21-year-old Maggie Caputi to run a half marathon and helped 42-year-old Kevin Johnson go from a chain smoker to a gym enthusiast.

"My habits have changed drastically every day after work instead of getting a snack or getting a cigarette, I now go straight to the gym and use that to burn off steam and anxiety," Johnson told the New York Post.

"Hypnosis just put a positive spin on my life and I look forward to going to the gym everyday."

The American Psychiatric Association endorses hypnosis, but warns it isn't a magic cure-all.

"Hypnosis is not going to be a magic bullet to get someone to get healthier eat better or workout. I certainly wouldn't tell anybody to put all their eggs in the hypnotherapy basket," Dr. Keith Ayoob, Registered Dietician at Albert Einstein College of Medicine, told the New York Post.