At age 54, Esther Goldberg has danced in front of 46,000 people at a sold-out Phillies game and behind a casino bar wearing little more than a see-through mesh shirt over a sparkly bra.
This is what Zumba can do to an otherwise mild-mannered masseuse and yoga instructor from Northeast Philly.
If you haven't heard about Zumba yet, Goldberg and more than 500 other certified instructors located within 25 miles of Center City will clamor to tell you how the Latin-inspired dance fitness phenomenon can not only get you in shape but truly change your life.
As Goldberg put it, "You never know where it will take you."
If it sounds a little cultish, that's because it is. I can say that because I, too, fell prey to the Zumba addiction and have been teaching it since February 2010.
Since there's nothing inherently Jewish about Zumba, I hadn't considered it newsworthy for the Jewish Exponent until another fellow instructor began ticking off names of members-of-the-tribe among our ranks.
Her point was confirmed a few months later when I posted a query for Jewish instructors on our Philly Zumba Instructor Network Facebook group. Fifteen people responded, generating a string of more than 40 comments that included lots of "oys" and a suggestion to form a Jewish burlesque group.
Short of these anecdotes, there's no data to indicate whether Jews comprise an unusually high share of Zumba enthusiasts. But there's no denying how much this fitness frenzy has reached into our local Jewish community. Aside from Jews who've made Zumba part of their weekly routine, at least six area synagogues have added classes to their line-up of community programs. A few teachers have even given it a Jewish twist, infusing Israeli music, Yiddish humor and their background in folk dancing to guide participants through the moves.
Although Zumba seems to be a relatively recent fad in the Northeast, it's been around in other parts of the country for years. A crowd of more than 6,000 instructors will mark its 10th anniversary at a sold-out convention this weekend in Orlando, Fla.
Of course, it's evolved quite a bit since 2001, when creator Beto Perez, a Colombian aerobics instructor living in Miami, pulled out some salsa music he had in his backpack as a desperate substitution for the formatted fitness tracks he'd forgotten. In 2005, Perez began licensing instructors to bring his format to their local health clubs. Instructor trainings and classes began cropping up around here about three years ago, according to fitness professionals.
By now, Zumba has morphed into a kind of international cultural showcase, with 12 million people taking classes in 110,000 locations around the world, according to the company's website.
Goldberg found Zumba, with its loud, quick, "out there" moves, a perfect counterbalance to the other forms of dance and yoga she'd been teaching since she was a teenager. What started as one class at Congregation Adath Jeshurun in Elkins Park quickly expanded to four, not counting the yoga she was already teaching there.
"People like to move their bodies but often feel like they can't dance since they didn't have training or they feel self-conscious," Goldberg said. With catchy music and repetitive steps, "Zumba eliminates that."
Because of the Jewish setting, Goldberg continued, it's easy to throw in "Hava Nagila" or other Jewish songs, talk about upcoming holidays or joke about how much everyone ate at Chanukah.
"My name is so Jewish, it's like I'm more comfortable fitting in," Goldberg explained. "It's like haimische. Especially if they are members of the synagogue, it's like, 'Wow, I can come to my synagogue and work out, it's here.' "
The phenomenon represents a shift for synagogues, wanting to be seen as community centers, not only houses of worship, said Adath Jeshurun's executive director, Robert Friedman.
"We're here anyway, so why not have the building open for different community needs," he said. "We like to think that it helps us when people come here and have a good feeling: 'I bring my kid for preschool and I play mahjongg and I do Zumba, yeah, maybe I should join here.' "
Growing up, instructor Donna Harris just wanted to dance on Broadway.
"My Jewish mother wouldn't hear of it," said the 62-year old. So instead, she went to Temple University and became a teacher. After retiring in 2008, the "frustrated dancer" finally got her chance to cut loose.
"While many of my friends went to Hadassah meetings, knitting circles and mah-jongg games, I was Zumba-ing like there was no tomorrow," recalled the Northeast Philadelphia resident.
The best part, she said, was seeing the older population she targeted coming out of their shells during class.
"Whatever is going on in their lives, Zumba helps them deal with it."
She can relate to that. Instead of dwelling on ailments that threatened to slow her down -- cervical cancer, depression, a non-malignant brain tumor, emphysema and severe hearing loss -- she concentrated on dancing.
Darcy Silvers, a copy-writer and instructor from Holland, Pa., said she wouldn't be surprised if the fact that she grew up listening and dancing to Hebrew songs made her quicker to hop on the Zumba bandwagon. Plus, she said, the format is very similar to Israeli dancing -- both associate each part of a song with a unique movement.
"To me it's like perfect because I get paid to exercise," Silvers, 52, said, adding that it's also a great way for women approaching menopause like her to help stave off weight gain and other side effects that come with that stage of life.
Silvers incorporates Israeli music in all of her classes -- including those at three Curves gyms -- but she saves expressions like "No schleppers allowed!" and "Shake your tushies!" for her synagogue group. Around Chanukah last year, she choreographed a routine to the Yeshiva University Maccabeats' "Candlelight."
As much as she loves Zumba, Silvers said, it troubles her that synagogues seem more interested in starting Zumba programs than Israeli folk dancing.
She's not the only avid folk dancer among the Philly Zumba clan. Silvers and another instructor, Beth Ladenheim, also 52, still frequent folk dancing almost every week, and a handful of their fellow dancers attend Zumba classes, too.
In folk dancing, Ladenheim said, the choreography tends to be more intricate and less athletic. She wanted to sweat, and Zumba certainly made that happen.
"As someone who loves to dance but not exercise, it seemed like a godsend to me during a time when I was desperately trying to lose weight."
Though Zumba classes tend to attract mostly women, men are specifically banned from the sessions Ladenheim holds at Lower Merion Synagogue and Congregation Beth Hamedrosh, two Orthodox synagogues.
For Orthodox women who don't belong to co-ed gyms for modesty reasons, "they would never do this anywhere else," Ladenheim explained. "I kind of feel like I'm doing a service by going into the synagogue and giving them an opportunity to do something that everybody else is doing."
Student Beth Gottfried said the class probably played a role in her losing 10 pounds since last fall. Aside from the fact that she can't go to other classes where men might show up, Gottfried, 52, said it was just convenient to have an option at her shul, where she could see friends and meet other Jewish women.
"There was no pressure to be perfect, you could mess up and nobody would judge you," she said.
Students pointed out that the synagogue classes tend to attract an over-40 crowd, which makes it less intimidating than a gym full of young, athletic exercisers. But there are plenty of younger Jews in the mix, too, like myself and 27-year-old Nicole MacDonald, an instructor from Willow Grove.
"Zumba doesn't judge based on age, weight, gender," MacDonald said. "It's for everyone."
Kate Nolt, a fitness consultant seeking a doctorate in kinesiology at Temple University, said she expects interest in Zumba will eventually die down like other fitness trends. Still, she agreed with Goldberg, who insisted that "there's too many people who love it and instructors who love it," for it to disappear soon.
Zumba seems to have reached a whole new level of fun compared with other workouts, Nolt said.
"It really does touch to the core of a lot of people," Nolt said. "Some people may not go onto a dance floor at a Bar Mitzvah or even a wedding, but in Zumba they're in a room with a whole bunch of people exercising and it feels really good. They're dancing but it doesn't even feel like a workout."
Not only does Zumba improve posture and figure, Ladenheim added, the social nature of it "leaves you feeling happy and wanting more movement instead of more cake."
Or, in my case, more movement and more cake.
Where to Catch Zumba Fever
If you haven't tried Zumba, these local instructors love to share their passion for booty-shaking.
Beth Ladenheim, 52, of Wynnewood
Zumba biker: Recently became licensed to drive a motorcycle, which means she's now eligible to join both Zumba instructor and Jewish motorcycle clubs (and yes, both groups exist!)
Catch her teaching (women only):
- Sundays at 10 a.m. (occasionally moves to 11:30 a.m.)
Congregation Beth Hamedrosh, 200 Haverford Road, Wynnewood. 610-642-6444
- Tuesdays at 7 p.m.
Lower Merion Synagogue, 123 Old Lancaster Road, Bala Cynwyd. 610-664-5626.
$8 drop-in or $36 for 5 classes, a portion goes to the synagogues
Darcy Silvers, 52, of Holland
Zum-Hora: If she had to play favorites she'd pick Israeli folk dancing, which she's done for 30 years, over Zumba, but she'll still make you "shake your tushie" in class
Catch her teaching:
- Wednesdays at 7:30 p.m. (switches to Thursdays in September)
Ohev Shalom of Bucks County, 944 Second Street Pike, Richboro. 215-322-1497.
- Wednesdays in the evening starting after Labor Day, time to be determined
Congregation Beth El, 375 Stony Hill Road, Yardley. 215-493-1707
Donna Harris, 62, of Northeast Philadelphia.
Baby Boom Zum: Couldn't get enough teaching after 35 years in the Philadelphia school district, so she brings Zumba to several older adult communities
Catch her teaching:
- Thursdays at 9:30 a.m.
Congregation Tifereth Israel of Lower Bucks County, 2909 Bristol Rd., Bensalem. 215-752-3468.
$60 for an eight-week session or $10 drop-in.
Esther Goldberg, 54, of Northeast Philly
That's Dancing: After leading a Latin-remix of Hava Nagila at a shul preschool class, Goldberg remembered one child exclaiming, "Now that is what I call dancing!'"
Catch her teaching:
- Mondays and Wednesdays at 6:30 p.m., Tuesdays at 10:30 a.m., and resuming in the fall, Fridays at 9:30 a.m.
Congregation Adath Jeshurun, 7763 Old York Road, Elkins Park. 215-635-6611 or email email@example.com 
$7 per class or $50 for a 10-class pass.
Heidi Solomon Barnett, 53, of Garnet Valley
Zumba lifeline: Dancing lifted her spirits when she was out of work, recently diagnosed with hypothyroidism, caring for a sick husband and dealing with a 16-year-old "in the throes of teen-age testing." "My husband did recover, my daughter is still in the midst of teen-age angst, but I feel empowered and blessed to have a wonderful network of Zumbettes," Barnett says.
Inspiring others: Newly certified, Barnett says she's proof that Zumba reaches across generations to help people get in shape and stick to a healthier lifestyle - it's "not just young instructors with buff bodies." She's planning to start teaching at a wellness studio in the fall.
Nicole MacDonald, 27, of Willow Grove
Confidence booster: Credits Zumba for introducing her to new friends, building self-esteem and achieving weight loss goals "without ever feeling like I'm working out."
Catch her teaching:
- Wednesdays at 6:30 p.m.
MB Fitness Studio, 409 County Line Road, Hatboro. 215-407-3631. $3 per class.
- Saturdays at 11 a.m.
Horsham Fitness Club, 217 Witmer Road, Horsham. 215-443-8510. $10 drop-in or $39 for six classes.
Shelley Engel, of Huntingdon Valley
Fundraising fever: Through Zumbathon fundraisers, often with a group of fellow instructors called "Spice Z," Engel supports walks for diabetes, breast cancer, AIDS and other causes. Her favorite was the Philadelphia Heart Walk last summer, where the Phillies Phanatic joined their performance at Citizen's Bank Park. "What a thrill it was when he ran out onto the field wearing Zumba-themed clothes and danced with me in front of a sold-out stadium!"
Catch her teaching:
- Saturdays at 10 a.m. and Tuesdays at 5:30 p.m.
Twining Valley Golf Club, 1400 Twining Valley Road, Dresher.
More classes start in the fall; for details visit: www.zumbawithshelley.com .