So when I decided to take my first Zumba class, I was nervous — and full of questions. Would my two left feet make it impossible to get through the class? Would I feel embarrassed that I don’t know anything about samba, cha-cha or salsa? Worse, would I fall so behind that I wouldn’t burn one single, solitary calorie? But I want to lose weight and get more fit, so I decided to give it a shot.

It turns out that Zumba, the ultrahip cardio workout performed to hyper Latin and international tunes, is not as hard as you might think. It doesn’t require memorizing a million dance steps and I was happy to find no one yells at you to keep up with the rest of the class. You dance, squat and tone your arms and legs while moving to an upbeat tune.

But I didn’t know this when I skulked into Janice Litvin’s Wednesday night Zumba Contra Costa class in Lafayette. Litvin wasn’t what I expected in a Zumba instructor. Though fit and trim, Litvin is older than your average twentysomething gym rat. A former high-tech recruiter, Litvin taught aerobics 20 years ago and recently found a new career teaching Zumba throughout the county.

In Litvin’s class, exercise is a party, she tells me. Oh, really? Because the biggest party for me is getting out of an exercise class.

“One of Zumba’s biggest strengths is the music,” she says. “It’s all fun, hypnotic, sassy Latin music. It doesn’t feel like a workout.” Dig into Zumba and you’ll find that’s the corporate message.

The story goes that Zumba was founded after an aerobics instructor forgot his regular music for class. So, instead of canceling the workout, he popped his personal stash of salsa and merengue in the tape deck and improvised to the music.

Since that mid-1990s mishap, Zumba was born. It has spread all over the world — there are 60,000 locations where the exercise classes are taught. There is a magazine devoted to the practice, a clothing line and workout videos offered on television and online.

I go to the top to ask Alberto Perlman, CEO of the Florida-based Zumba Fitness, which is Zumba’s corporate headquarters, why Zumba is so hot. He nearly repeats what Litvin said.

“It’s a party. While other fitness programs are about ‘no pain, no gain’ and hard work, Zumba is about fun and partying,” he says via e-mail.

Well, I like to party.

But I still wasn’t convinced Zumba was for me, so I pounced on Litvin’s students when they trickled in the door for the 6 p.m. class.

Nicole Burnette of Pleasant Hill hates to be on stage. She’s not a dancer, and she’s not necessarily the type of person who wants to be “out of my shell.” She sounds a lot like me.

She picked up Zumba — a solo movement class rather than partner dancing — a couple of months ago when her friend recommended it. She says she fell in love with the workout.

“The time goes by really fast, and you don’t know you’re working out until you’re dripping in sweat,” she says.

I talked to more students, and they all agreed: Zumba doesn’t feel like exercising. At the end, they say, they are sweating and energized. Some also follow Litvin to her other classes. They say a good Zumba teacher is something to cherish, as not all Zumba instructors are created equal.

Soon, Litvin starts the class. I follow, clumsily, as she does some cha-cha steps and moves her hips to the beat. She is active and engaged in the class, coming around to correct form or show the best way to swirl the hips. She reminds us to bend our knees.

When she puts in a new song, she announces the moves we’re going to do — a squat here, a double-step there — and I follow, keeping my eyes on her and doing my best to remember that there are two steps to the left and three to the right this time. We cheer and clap after every song. The women in the class — they’re all women — take a water break while I recall, thankfully, that this is a workout and not preparation for a stage production.

When the next song starts, I notice that the woman standing in front of me knows all the moves. She kicks her knees up high during some of the jumps and lunges low during the squats. I put a good effort in, too, lunging down to the ground and kicking as high as I can, but she is definitely out-lunging and out-squatting me. She’s sweating more and is probably one of those students burning 1,000 calories rather than 500.

Then I realize, despite rumors that Zumba is difficult, I’m picking it up easily. And yes, it is fun. You get out of it what you put into it, exercisewise. If I just want to tap a toe and move a hip here or there, I can breeze through the class and have the same amount of fun as I would if I went all out with my squats, twists, turns and shakes.

At the end of class, which includes a warm-up and a cool-down, I am sweating and energized. I can’t wait to party again.