Catherine Duffy was at Laurel Race Course, cheating. Her doctor had told her to postpone any trips to the track because those neck-and-neck stretch duels and photo finishes might be too strenuous for her ailing heart, which had faltered twice since October.

But after almost 60 years of playing the horses, Duffy, 74, couldn't hold back. Besides, she said, "I can't stand just doin' nothin'."

Elderly horseplayers are as diverse as their handicapping methods, but their motives are essentially uniform: to battle boredom. At Laurel, the battle is waged frequently; the track's director of admissions, Hugh Mills, estimates as many as 30 percent of the patrons are senior citizens.

"If you're here every day as I am," Mills said, "you see the same faces every day."

One of those faces is that of Duffy, a former member of the Baltimore city council.

"When I'm in the hospital, I go crazy," she said. "(The doctor) said I could go (to Laurel) next week. I guess I'm a little early."

After three races, she hadn't had much excitement, and she wasn't happy about it.

"I'm stuck for $35 already," she said, waving a program in disgust. "But don't worry, honey; I'll get it back."

She had traveled from Baltimore by bus with other members of Chatterbox, a women's social club that has an annual day at the races. About half its members are senior citizens, according to its president, Shirley Bukowski.

The women occupied a block of tables in Laurel's clubhouse terrace, ate soup and filet mignon and apple pie and bet on horses with nice names like Hat Full Of Stars, Time For Silver and April Makings. Duffy would have no part of that; she reached down to a chair beside her, lifted her purse and pulled out the Racing Form.

"It's my bible," she said. "I like class better than anything, but I also take the breeding and the times into account. I don't buy them tout cards. They take you for a buck, a buck and a half, and those bums don't know any more than I do."

She didn't hit the fourth race, either. But at the next table, an elderly woman bet $2 to win on Caracole, because the name sounded as if it could have been Italian. The horse never trailed and paid $31.60.

On Tuesdays and Thursdays, senior citizens pay $1.50 half-price grandstand admission at Laurel. So Columbus Demar, 65, a retired government worker, boarded a bus in Gaithersburg and got off at the Greyhound terminal in Silver Spring.

Washington Tours runs a bus to Laurel via the District and Silver Spring each racing day. Demar paid $7 and waited in the stuffy little depot.

"I just go to the track to pass time," said Demar, who lives with a daughter now that his wife is in a nursing home. "I get tired of sitting around the house."

Gradually, 13 more Laurel-bound people, most of them elderly, filed into the station. Among them: Charlie Fletcher, 69, a former salesman from Kensington who said: "I do better with stocks than with the horses, but watching prices fluctuate isn't my idea of excitement"; a 78-year-old Adelphi woman who bemoaned two ill-fated wagers on the Redskins and proclaimed the Bears a cinch to win the Super Bowl; a retired army administrator who demanded anonymity because "I have alimony to pay, and I can't have my wife finding out about this"; and Larry Gill, an army veteran from the District who was discharged with full disability pay.

"If I didn't go to the track," Gill said, "I'd go to the grocery store with the boys, gettin' in trouble."

Helen Hurly is kept busy with her job of coordinating group outings to Laurel. Many of those outings are arranged for senior citizens clubs.

"These people don't come here with the stigma that they're old," Hurly said. "They're catered to. Some are very full of life, but many of them maybe can't walk very well, or they need crutches or a wheelchair. We try to take care of them without taking away their dignity."

Of course, not all senior citizens dine in the clubhouse. The bus riders from Silver Spring were scattered about the grandstand, and as the afternoon waned, so did most of their bankrolls.

In the end, the woman from Adelphi had cashed no tickets. She said: "It was just my dumb decisions that cost me; I shoulda hit a couple exacters."

The retired army administrator, who said he was "strictly a numbers man," failed to connect on his 2-5 daily double or any of nine 2-5 exactas.

Demar was close to even.

Gill saw a $10 profit vanish in the final race.

Fletcher lost $52, and he was steaming.

"It's never fun when you lose," he said. "In this game, the end always justifies the means."

In the upper grandstand, Al Bernstein, 81, held a cigar in his left hand and a calculator in his right. He had driven his Dodge Dart alone from Arlington.

"This is where I go for action," he said. "I'm not about to sit around waiting for the day when they can drop me in a pine box . . . And when I leave here, I always leave happy. I feel like I can't lose, as long as I wake up in the morning and can get out of bed."