(FORTUNE Magazine) – He takes 35 business trips a year, but James Tillotson doesn't let a hectic schedule cut in on his favorite exercise: ballroom dancing. Vice president for research and development at Ocean Spray Cranberries, Tillotson, 57, has waltzed, rumbaed, and tangoed from Shanghai to Zurich. ''I could sit in the hotel and get fat or drink a lot,'' he says, ''but I prefer to skip dinner and go dancing.'' Executives at Ocean Spray kid him about his passion, but he doesn't mind. Since he began dancing seven years ago, the 6-foot 2-inch Tillotson says he has lost 40 pounds, improved his posture, and become more confident in social and business situations. One other attraction he cites: ''There's no other sport where you can walk into a room and within 20 minutes have all of the women in your arms.'' Ballroom dancing is on an upswing across the U.S. The surge started with the discomania of the mid-Seventies, which ignited widespread interest in dance, even among men notoriously bashful, if not terrified, around dance floors. Dance teachers say the Public Broadcasting Service has chipped in by carrying major ballroom dance competitions since 1981. Then, last fall, the all-dance revue Tango Argentino became one of the hottest tickets on Broadway and propelled interest to the loftiest heights in years. Pinning down the number of U.S. dance students is impossible because most teaching studios are small and independent, but the figure is surely rising. At the two major nationwide teaching chains, Fred Astaire International Dance Association and Arthur Murray International, combined new enrollments rose from about 85,000 in 1982 to about 96,000 last year.

Some foxtrotophobes don't call the dance school until they have to -- daughter's wedding is three weeks away -- but many others take up dancing for exercise or to relieve tension. Many men, such as Jody Simons, 58, manager of the Drexel Burnham Lambert investment firm's Boston office, just got fed up with being klutzes. Despite his wife's urgings at business and social affairs, he refused to dance. ''My feet just wouldn't move,'' he explains. Two years ago, on a whim, he signed up for lessons with a local instructor, and his wife joined him three weeks later. Today, he says, ''I go dancing at every opportunity. We hardly ever go to the movies anymore.'' FOR SOME ARDENT HOOFERS, especially those who have excelled in sports or are overachievers at work, dancing for the simple fun of it is not enough. They need to compete. They have plenty of opportunity. Dance studios set up a lot of competitions so students can mingle and because students take more lessons when gearing up for a championship. Scores of other regional and national contests give chances to dancers of almost any ability. The National Dance Council of America (headquarters: Vienna, Virginia) sets the judging standards, and two newsletters report the competitive calendar in detail: Dance Week, published in McLean, Virginia, by Richard S. Mason (703-356-9113), and The Amateur Dancers, published in Baltimore by the U.S. Amateur Ballroom Dancers Association (301-744-2229). Some competitors become obsessed with their hobby. John Gay, 35, a senior vice president at Southeast Bank in Miami, rarely dances socially anymore. He and wife Lori, a professional dance instructor, have for the past three years been U.S. theatrical dance champions in the pro-am division. Gay practices about 20 hours a week. Ronald Ford, 36, a senior business analyst at Amoco Chemicals Co. in Chicago, won the U.S. Amateur Ballroom Championship in 1981 and turned pro two years ago. Practicing, teaching, and competing take him about 40 hours a week. He spends $10,000 to $12,000 a year on dancing, which is more than his teaching income. Other aspiring Freds and Gingers remain more footloose. Rod Reader, 42, has been competing for about a year and insists that he ''will never turn my hobby into a monster.'' Says Reader, a partner in Downes & Reader Lumber Co. of Stoughton, Massachusetts: ''I never lose because I go for fun.'' Richard Cyphers, 36, manager of E.F. Hutton's Hartford office, takes a similar attitude: ''I look at a competition as being in a fairyland for a weekend. We get dressed up and play pretend.'' Finding dance instruction is easy practically everywhere in the U.S. The two major chains, Arthur Murray and Fred Astaire, together have about 400 franchises. To find the nearest, call national headquarters (Murray: 305-445-9645; Astaire: 305-238-7911) or check the yellow pages. You will also probably find listed several independent studios, which outnumber the franchises by about 6 to 1. Many colleges and universities offer day and night classes in ballroom dancing. Learning need not cost much. An Astaire studio in New York City, for example, offers an introductory package of four lessons for $12; after that, group lessons cost $15 an hour. Private lessons are expensive: generally $30 to $50 an hour, often much more for the time of teachers who turn out champions. Most major cities have public dance halls for ballroom enthusiasts, usually offering live music and often charging admission. Go alone without qualms. Everyone is there to dance and expects to ask or be asked. And the dance halls and their denizens have largely left behind the slightly less-thanwholesome aura some once had. Among the standout spots: NEW YORK CITY. Roseland (239 West 52nd Street; 212-247-0200) is mecca for serious dancers. A surprising blast from the past: taxi dancers, who will spin around the floor with the customers for a dollar a dance. The Red Parrot (617 West 57th Street; 247-1843) was once a roller disco, is now a nightclub with dancing until 4 A.M. BOSTON. Moseley's On The Charles (Dedham, Massachusetts; 617-326-3075) is a giant ballroom (10,000 square feet) for serious dancers; 14 miles from downtown. Parker House Hotel (60 School Street; 227-8600) caters to a young crowd; good food is available. The Bay Tower Room (60 State Street; 723-1666) draws a well-to-do crowd and offers a spectacular view of Boston harbor; the dance floor is small and the food is good. CHICAGO. Willowbrook Ballroom and Restaurant (Willow Springs, Illinois; 312-839-1000) has dancing Thursdays, Saturdays, and Sundays; 18 miles from downtown. DALLAS. Four Seasons Ballroom (4930 Military Parkway; 214-349-0390) has dancing Wednesday and Friday nights. SAN FRANCISCO. Hyatt Regency hotel (5 Embarcadero Center; 415-788-1234) holds tea dances in the Atrium lobby every Friday afternoon from 5:30 to 8:30. Cesar's Latin Palace (3140 Mission Street; 415-648-6611) is a converted bowling alley that holds 1,000 people. Sunday is tango night, with free lessons from 8 to 9 P.M. and a band from Buenos Aires. A rose for clenching in the teeth is optional.