“Ho, ho! Ha, ha, ha!”

“Ho, ho! Ha, ha, ha!”

A group of men and women are chanting (with gusto) in unison, clapping their hands to punctuate each syllable. Despite appearances, no joke has been told, no comedy film is being screened.

‘Participants are repeating the mantra of the Laughter Workout Club, led by professional clown and certified laughter leader Marilyn Galfin.

Here, laughter isn’t humor-based – it’s simulated through exercises. According to proponents such as Ms. Galfin, these laughter exercises help promote health and happiness. “Our culture is very serious and uptight,” she said. “But we’re naturally born in a blissed-out state. That’s what I’m encouraging.”

Ms. Galfin received her laughter leader certification in 2001 at a workshop held by the World Laughter Tour, a group dedicated to spreading the message that laughter is good for you. “The mentality in North America goes back to the Puritans, of amusement as verboten,” said the group’s founder, Ohio-based psychologist Steve Wilson, in a phone interview. “That still runs deep in our culture.”

Mr. Wilson was inspired in his quest to spread cheer by Dr. Madan Kataria, who popularized laughing yoga in India in the mid-1990s. In 1998, Mr. Wilson came up with the idea of therapeutic laughter clubs headed by qualified instructors who could offer “guidance and motivation.”

“It’s not a new notion that laughter could have health benefits,” Mr. Wilson said. “The idea that laughter is the best medicine goes back to Proverbs in the Old Testament.”

Science backs up Mr. Wilson and Ms. Galfin’s beliefs. Laughter researcher and psychoneuro-immunologist Dr. Lee Berk of Loma Linda University, in Loma Linda, Calif., who is also on the professional advisory committee of the World Laughter Tour, says that the benefits of laughter exercises are “not too dissimilar from repetitive healthy behaviors.”

In other words, laughing can help you reap cardiovascular benefits, reduce your stress hormones, and give your immune system a boost.

It’s also significant that the laughter isn’t humor-based but rather simulated, what Dr. Berk calls “mirthful laughter.” This removes language barriers, cultural biases, and personal tastes, allowing participants to achieve a pure, joyful experience. According to Dr. Berk, the positive effects are the same with or without the joke.

Or, as Ms. Galfin puts it, “Fake it ’till you make it.”

Ms. Galfin supplements her laughter leader training with elements from her background in theater. Early on in the class, she has the group of seven women and three men, ranging in age from their 20s to their 50s, stand in a circle. Rather than give a standard introduction, each person is instructed to step forward, say his or her name, and perform some original, individual gesture. Everyone else then says hello and performs the gesture as a group. “You’re expressing yourself!” Ms. Galfin tells the class. “You’re saying, ‘This is who I am.'” It is hard to remain serious when grown men are twirling on one foot or striking poses like a Broadway star while saying their name, and the group quickly starts to giggle and unwind.

Next come classic simulated laughter exercises. To get the ball rolling, Ms. Galfin tells the class to walk freely about the room making eye contact with each person they meet. When eye contact is established, each person must break into simulated laughter. Initially, there’s some shyness involved, but it turns out that laughter – even the simulated kind – really is contagious.

In the “Transformation Exercise,” the group is divided into two lines. Everyone rushes aggressively toward one another, and when they meet in the center of the room, they burst into laughter. This is followed by the “Laugh Heard Round the World” exercise. Ms. Galfin produces an inflatable globe. Standing in a circle, one member of the group throws the ball, and whoever catches it must laugh. One staid-looking gentleman abandons himself to the exercise, producing a surprisingly sinister guffaw from somewhere deep inside his belly.

Ms. Galfin urges everyone to let loose and tap into their inner child: “Children are in the zone and laugh for the sake of laughing,” she says. “Return to your original state when you were free and joyful.”

First-timer Melanie Audy, a 31-year-old sommelier from Weehawken, N.J., admitted she felt awkward at first. But she unwound in no time. “It’s a great environment,” she said.

This was Randi Friedman’s second time participating in one of Ms. Galfin’s monthly workshops. Ms. Friedman, a 47-year-old live captioner for the deaf and hard of hearing, said she couldn’t wait for her second class. “It’s a gift,” she said. “I love my inner child, but there aren’t too many forums where we can be authentic about our silliness. But there are no rules here.”

Good news for Ms. Friedman: Not only does the act of laughing release endorphins, but, according to Dr. Berk, anticipating the class has a positive effect on mood as well. “Anticipation in mind/body medicine is very important,” he said. “How neat to get [all those benefits] for simply enjoying some laughter.”