WASHINGTON (AP) _ A marketer who can get someone away from the TV long enough to make a telephone call can build an exercise equipment empire.

That's how it's done with direct response advertising, the commercials with the phone numbers at the end. And Ovation Inc., the Los Angeles-based distributor of Thighmaster, is a case study in how to transmute women's unhappiness with their legs into desire for a product.

From a standing start, Ovation has blanketed the country with ads for its coil-loaded curved bars, avoiding the expense of major networks by buying time on cable and individual stations.

''It really is guerrilla marketing,'' said Joseph Grace, Ovation's chief financial officer.

Ovation chose exercise equipment because it seemed a natural for TV, Grace said.

After visiting trade fairs and conventions, company officials settled on the forerunner of the Thighmaster, a device called the V-Toner, which was being marketed as a ''laptop gym'' for the whole body, Grace said.

Thighmaster's instructions show uses besides strengthening thigh muscles, said Peter Bieler, Ovation's president. But the company officials didn't want to sell Thighmaster that way on TV.

''In direct response, you have to pick one approach - and, from the name of the product to the TV spot, this is for flabby thighs,'' Grace said.

Flabby thighs are ''a very specific and emotional problem that women wrestle with every day,'' Grace said.

And emotions count a lot, he said.

''''Buying on TV is an impulse buy,'' he said. ''You have to have a very compelling offer to get people out of the chair.''

The spot's opening shot gets right to the point - a slow pan up what the camera directions describe as ''a great pair of legs.''

Another big question: whose legs.

''We wanted a channel-stopper, someone who is believable, the right age, appealing to the women we wanted to sell to,'' Grace said. Those women are 35-50, and willing to work for muscle tone, he said.

Suzanne Somers got the job of demonstrating Thighmaster. She's the right age, very fit, well-known and likeable, Grace said.

The fact that those bars are to be squeezed as you exercise may help sales. ''Wide ranges of motion look nice on TV,'' said Bob Schnabel, executive vice president of Fitness Quest, a competing company in Canton, Ohio.

Thighmaster's spots went on air in April of 1991. ''We spent probably $10 million in media over time,'' Grace said. But with direct response, money made from the initial sales can get plowed back into more ads: ''It's very expensive, but it's a self-funding exercise.''

What's more, many media companies let marketers advertise on a per-inquiry basis, taking a cut of sales instead of charging for air time.

And, by using different phone numbers in differing versions of the spots, companies can measure what happens when they tinker with the message or the price. The best sales came at $19.95, Grace said. ''Increasing the price to $29.95, orders dropped,'' he said.

But TV was only the start. Customers who kept Thighmaster going during the early ads were also helping Ovation enter retail sales later. ''Our rule is that 10 percent of people buy off TV,'' Grace said. ''The real benefit from direct response is that you're making the other 90 percent aware.''

Ovation says Thighmaster sales are surging, but another industry official wonders how long it will remain.

''Every time someone orders it, you decrease the market by one,'' said Ron Bliwas, president of A. Eicoff and Co., Chicago, a direct response TV agency. ''The Thighmaster will eventually run its course.''

Another question is whether Thighmasters will eventually get relegated to closets or basements, where much home-use exercise gear winds up. The company has not checked to see if purchasers continue to work out, Bieler said.

However, he said, Thighmaster is easy to use, so he suspects they still are.

END ADV for Release Mon March 23