At age 75, Judi Sheppard Missett is still dancing, still teaching, and still CEO of Jazzercise, the ur-dance-fitness company she founded and that celebrates its 50th anniversary this year. She also has a new book: Building a Business With a Beat. Created when Jane Fonda was better known for Barbarella than for aerobics, Jazzercise today is a $100 million business with more than 8,500 franchisees, and it cracked the Inc. 5000 in 2010, at the ripe age of 41. The company not only forged fitness culture for women--It's fun! It's easy! It's social! We don't judge!--but also has helped thousands of women become business owners, some of whom have launched multiple studios to teach the program. --As told to Leigh Buchanan

My mother saved my dance lessons. Maybe that's how it all started.

When I was 11, my instructor of seven years left Red Oak--the small town in Iowa where I was raised. So my mother recruited young dance assistants from studios in larger cities to come teach me and other local children. She found them facilities, produced their recitals, and sewed their costumes--an early version of what I would do for my instructors in Jazzercise.

I went to Northwestern University, and started training at Giordano Jazz Dance Chicago. The owner suggested I teach a program for the moms whose kids were in his beginners' classes. This was 1969. I created a class that was hard--disciplined with lots of technique.

Almost everyone dropped out. They said, "You know, Judi, we don't want to be pro­fessional dancers. We just want to look like them."

So I started a new class with easy steps and lots of positive encouragement. I also turned students away from the mirror. Fifteen people showed up for that first new class. By the third, I had 60.

In 1971, I was teaching 35 classes a week in community centers and YMCAs around San Diego, where my husband, Jack, and I had moved. I developed nodules on my vocal cords from yelling instructions over the music, and my doctor warned if I didn't slow down, I'd lose my voice entirely.

So I recruited my best students and taught them my methods. They took over some of my classes, and I collected a percentage of their sales for supplying choreography and marketing help.

San Diego is a military town. Many of my students were military wives, or were themselves in the military. They moved around a lot and took what by then I called Jazzercise with them. And their students became teachers, spreading the program organically. All underwent Jazzercise training and certification. Every 10 weeks, I sent them videotapes of new choreography, created by me and produced by my husband.

Today, when you say "Jazzercise," people say, "Oh, are you still here? Are you still doing what you did in the '80s?" Yes to the first question. No to the second.

In the late 1970s, I appeared on Dinah Shore's show Dinah!, wearing a leotard on which a friend had silkscreened "Jazzercise." The response was so huge we launched Jazzertogs (later Jazzercise Apparel), which we sold through our instructors--and which remains a large part of our business.

By 1981, I had about 1,000 instructors around the country working as independent contractors. My accountants and lawyers told me the arrangement wasn't, strictly speaking, legal. They could be either employees or franchisees.

The instructors had always been free to make what they wanted of Jazzercize. Some taught a few classes a week as a hobby. For others, it was a full-fledged business. Either way, they felt ownership. So I chose franchises, even though that model wasn't big at the time.

In 1984, the Olympics came to Los Angeles. We approached the organizers offering to provide, for free, 300 dancers for the opening ceremony. They agreed--it was a phenomenal experience. After that, Jazzercise was invited to perform at NFL halftimes, NBA halftimes, and the 100th anniversary of the Statue of Liberty.

I landed a weekly slot demonstrating moves on PM/Evening Magazine, a forerunner of Entertainment Tonight. Our visibility skyrocketed. By the mid-1980s, the two biggest franchises were Jazzercise and Domino's Pizza.

But we were also starting to get competition. Jane Fonda and Richard Simmons had been around for some time. (We actually beat out Jane--ours was the first exercise video to go gold, in 1982.) But their programs were built around an individual celebrity, while Jazzercise was built around our franchisees.

Still, by the early '90s, some of those franchisees were starting to retire. Potential new franchisees had other options, like Pilates and yoga. The recession also hurt: 1991 was our first unprofitable year--our only one to date. We responded with a rebate program that rewarded instructors for signing up lots of students. The money attracted many new franchisees and kept the veterans on board.

Today, when you say "Jazzercise," people say, "Oh, are you still here? Are you still doing what you did in the '80s?" Yes to the first question; no to the second.

We wouldn't have survived if we had kept doing what we did back then. We've updated our instructor communications with every shift in technology: from videotape to CDs to DVDs to streaming. We've developed all kinds of special classes, including high-intensity interval training, core, and fusion, which mixes cardio and strength training.

I still create and send to franchisees new choreography and new music every 10 weeks to keep things fresh and exciting. My daughter, Shanna Missett Nelson, became president of the business in 2010. We kind of run it together.

I don't think of all these new fitness programs as competitors. I think of the couch as my competitor. More than 80 percent of all adults don't exercise enough, so there are plenty of potential new customers for all the fitness programs. Any company getting people to move, in my opinion, is great.

When we were starting out, I remember applying for a line of credit. (We didn't need it, but I thought it would be good to have.) The bank president looked at our numbers, and he looked at me, and he said, "I think this is a fad. You're just exercise girls."

Seven years later, that bank went out of business. Fifty years later, I'm still here.

And thriving.

From the October 2019 issue of Inc. Magazine