Tricia Sanders says her boss has been very agreeable in allowing her to pursue a variety of children and youth ministry activities at the Crafton United Presbyterian Church on Bradford Avenue.

But when she told Ed Bowen about her idea to host a laughter club, the pastor raised an eyebrow and wondered, "What is a laughter club?"

A laughter club is a gentle exercise session of breathing, stretching and laughter actions that promote good physical and mental health.

Laughter clubs are the outreach component of the World Laughter Tour, a Gahanna, Ohio-based organization which was founded by Steve Wilson, a psychologist, mental health educator and, as he calls himself, "cheerman of the bored."

During a 1998 lecture tour he conducted in Bombay, Dr. Wilson met physicians who had been conducting laughter clubs in India in which they shared their beliefs about the power of laughter and humor to promote good health and world peace.

Adopting the slogan, Think Globally, Laugh Locally here in the United States, the World Laughter Tour began training people as certified laugh leaders to establish and lead community laughter clubs.

Mary Mullen, a librarian at the Bethel Park Public Library, is one such laugh leader.

During a recent laughter fitness class at the Crafton church, Mrs. Mullen told the group of about 35 participants that laughter activates the immune system, decreases stress, relieves depression, exercises the heart and lungs and improves digestion and mental functions.

"It prevents hardening of the attitude, too," she joked.

Jokes are, surprisingly, not a regular part of the laughter club. Mrs. Mullen explained that, because everyone has a different sense of humor, instead of using jokes, the clubs use laughter exercises which both simulate and stimulate laughter.

For example, after some mild stretching exercises which participants can do while seated, Mrs. Mullen asked everyone to stand and greet one another by shaking hands and saying "Aloha ha ha ha."

As the participants went from person to person greeting each other this way, most couldn't help but laugh at the silliness of it, which is exactly the point, according to Mrs. Mullen.

The program works from the premise that too many people suffer from a syndrome called YALE -- You are not laughing enough.

It is believed that children laugh 200 to 300 times a day, but by the time people reach adulthood, the number of times they laugh is reduced to 10 to 15 times a day.

"Laughter clubs are a proactive way to regain an enthusiastic sense of playfulness," Mrs. Mullen said.

Mrs. Mullen is working to recruit others to become laugh leaders. To be certified, new leaders would have to travel to Ohio for a two-day training seminar, as Mrs. Mullen did at the urging of one of her library patrons.

Although she has not recruited any leaders, at the Crafton session, Linda Hannon, of Pennsbury Village, said she was interested in learning more about leading laughter clubs.

"I felt it was a really good thing," Ms. Hannon said, adding, "I think it could help point me in a more positive direction."