A sidesplitting new fitness fad is spreading like wildfire. It’s called laughter yoga – part traditional yoga, part improvization and all silliness.

I think I’ll like this kind of workout. I always have a keen sense of well being and relaxation after a good laugh, and we can usually find humor in the most unexpected places if we’ll just look hard enough.

The waitress I saw yesterday rushing around the cafe with a big piece of toilet paper stuck to her shoe cracked me up. My step mother who set off the burglar alarm when she shut the toilet seat in the middle of the night was a doozie too. And I can’t count the times I’ve had the overwhelming urge to giggle in church (but I guess that doesn’t count since the laugh is squelched).

Once when my son was small and communion was being passed, I prevented him from partaking because he was too young. As I ingested the bread, he yelled out in a sing-song voice “You’re doing to get cavities.” The whole row began to shake. Sometimes when I’m feeling blue, I dredge that episode back up and get a good laugh even today.

Numerous scientific studies have found that daily laughter can help lift depression, lower blood pressure and boost the immune system.

Most people think they have to feel good first in order to laugh. But you can start from nothing, you can even start feeling unhappy and just laugh as a form of exercise, and happy feelings follow,” said one laughter yoga teacher. He had on mismatched sneakers and wore his suit backwards.

If you don’t feel like laughing, fake till you make it he said. If you’re laughing with someone else, fake laughter can quickly become very real.

What Is laughter anyhow? I never really thought about it before. Wonder what makes you make those strange sounds and vibrate at the same time? I did some research and here’s what I found…

Laughter consists of two parts — a set of gestures and the production of a sound. When we laugh, the brain pressures us to conduct both those activities simultaneously. When we laugh heartily, changes occur in many parts of the body, even the arm, leg and trunk muscles.

Under certain conditions, our bodies perform what the Encyclopedia Britannica describes as “rhythmic, vocalized, expiratory and involuntary actions” — better known as laughter. Fifteen facial muscles contract and stimulation of the zygomatic major muscle (the main lifting mechanism of your upper lip) occurs. Meanwhile, the respiratory system is upset by the epiglottis half-closing the larynx, so that air intake occurs irregularly, making you gasp.

In extreme circumstances, the tear ducts are activated, so that while the mouth is opening and closing and the struggle for oxygen intake continues, the face becomes moist and often red (or purple). The noises that usually accompany this bizarre behavior range from sedate giggles to boisterous guffaws.

Laughter can be of the “ha-ha-ha” variety or the “ho-ho-ho” type but not a mixture of both, he says. Provine also suggests that humans have a “detector” that responds to laughter by triggering other neural circuits in the brain, which, in turn, generates more laughter. This explains why laughter is contagious.

Humor researcher Peter Derks describes laughter response as “a really quick, automatic type of behavior.” “In fact, how quickly our brain recognizes the incongruity that lies at the heart of most humor and attaches an abstract meaning to it determines whether we laugh,” he says.

So go on, laugh it up. It’s good for you.