When a 39-year-old realtor took up harness racing in the fall of 1951, there was no reason to believe a legendary career had just begun.

For Dave Legum it was just another challenge. Today, Legum ranks as one of Maryland's leading trainer-drivers. Legum credits his many successes in both business and sports to an insatiable desire for competition.

"I've been that way all my life; I'll be damned if I know why," said Legum, who has slowed down little despite celebrating his 65th birthday May 28. "The excitement of competition has been my whole life. And you'll find most athletes are that way.

"I can't sit still," said Legum, who lives with his wife Francis at 3003 Van Ness St. NW. "And every friend I have tells me to slow down. But when I slow down, I have no pep. I've got to keep going."

On a typical day, Legum arrives at Rosecroft Raceway in Oxon Hill by 6:30 a.m. for a 2 1/2-hour workout. From there, he heads to his real estate office, where he stays from 9:30 a.m. until 1 or 2 p.m. After an afternoon of tennis or golf at Woodmont Country Club in Rockville, and dinner, Legum goes back to the track at about 7 p.m., where five days a week he races and stays until about 11 p.m.

He now has an assistant trainer who takes over on those occasional mornings he doesn't go to the track, but Legum said he followed that daily routine for 15 years, six days a week.

Having groomed horses at thoroughbred tracks Pimlico, in Balitmore, and Laurel, Legum always wanted to become a jockey. But at 155 pounds - he now weighs 156 - he was far too heavy.

So when harness racing came to the area in 1948, Legum became an enthusiast. His first horse was True Dust, a two-year-old filly he purchased for $2,500. Legum's favorite animal was Brown Star, who captured the 1962 Governor's Cup at Brandy-wine, Del., in a record 2:00-23/85. The winner's share of $15,000 is only a fraction of what the purse would be in a similar race today.

Brown Star, now 19 years old and at stud, earned Legum $80,000 in two years of "overnighters," races that offered only $1,000 or $2,000 for the victors.

Legum now operates the Midway Stable in poatnership with four other Washington businessmen. The stable has 17 horses, including seven yearlings. The top two horses, Eastwood Jug and Ray's Bret, are not racing right now because they are recovering from injuries.

In his younger years Legum also raced motor boats in major regattas and cars on the nation's dirt tracks.

"I lived sports, every sport," Legum said. "When I went to work at 15 as a musian, I was still active in baseball, golf, basketball, football, everysport - Harness racing has been my biggest loce - the competition, the danger.%

When Legum was 15, he began playing violin and string bass for dance bands at the Willard, Shoreham and Mayflower Hotels in Washington. By 19, he was touring the United State with the musical Hollywood Collegians and simultaneously riding in horse shows on the circuit.

Legum attributes his success in business to his competitiveness. "As you know, there's nothing more competitive than business," he said. "It's all the same."

In 1945, Legum joined with Raymond J. Gerber to form Legum and Gerber Realty. After Gerber died in 1972, the firm became Legum Realty. The company has 25 employees and handles all types of realty work, although it specializes in property management, Legum said.

Eight times Legum has earned the honor of best driver at Rosecroft after bringing home the highest percentage of winners during a session. In the first month of the present meeting, Legum recorded seven victories, five seconds, and three thirds in 26 starts. Yet he has not parted with some of the dreams he had in his earlier days of harness racing.

"You're always looking for a Hambletonian (the top race in the trotting Triple Crown, held in DeQuoin, III.) winner, a Little Brown Jug (the top jewel in the pacing Triple Crown, staged in Delaware, Ohio) or a Triple Crown," Legum said.