Two years ago, my father, then 61, became a statistic -- the kind health officials would like to see more often. After smoking nearly two packs a day for years, he traded in his cigarettes for a mountain bike.

He now monitors his mileage -- 4,000 cumulative miles on northern California's ubiquitous bike trails -- just as he used to keep track of the Southern Pacific Railroad trains he once supervised. Meanwhile, he has avoided about 25,000 cigarettes.

My father is a perfect example of the federal government's latest anti-smoking campaign aimed at the older, hard-core smoker who finds it especially hard to quit. Even though younger smokers who quit reap the greatest health benefits, those who do so at older ages also lower their risks of heart disease, stroke and cancer.

Like many older smokers, my father started at age 18, the day he went into the Navy in 1945. He smoked for the next 15 years, then quit for a decade. In 1967 when he was transferred by the railroad to a new town and lived alone temporarily, waiting for my mother and his four children to join him, he started again. His habit accelerated, even though it was a secret he tried to keep from all of us, mostly by smoking at work or by sneaking clandestine cigarettes when he volunteered to walk the dog or to run errands.

Several years ago at Christmas, I was shocked to learn that he had become a heavy smoker. I broached the subject gently, more as a health writer than as a daughter, and asked him to give up smoking for the sake of his health.

Half-heartedly, he said he would try. But a year later, he was still smoking, and I employed a more desperate approach, and even threatened not to be at his bedside if a smoking-related illness of his own making struck. The clincher was an appeal on behalf of his grandchildren. "Don't you want to be around to see them grow up?" I asked?

He did. Two years ago, when I arrived home for Christmas, my father told me he had just quit. At my suggestion, he got a prescription for nicotine gum, which he chewed furiously. "It got me through the withdrawal," he said.

Somehow he made it through the first crucial months, surviving a business trip in the smoking section of an airplane -- his travel agent didn't know he had quit -- and backsliding just once, when a fellow smoker offered him a cigarette. "I thought it would be wonderful, but it wasn't," he said. "It didn't taste so good."

Retirement, nine months after he stopped smoking, posed a new challenge, but he not only stuck to his plan, he took up bicycling as a hobby.

Now, he's basking in the glory of someone who has fought the enemy and won. Like 90 percent of ex-smokers, he did it on his own and he's proud of that. While many ex-smokers complain about weight gain, he countered the urge to eat more and actually trimmed down, by bicycling.

In addition to feeling better -- "I have so much more energy," he says -- he feels more in control of his life. "One of the main benefits is getting out of the logistics of smoking. Because you are addicted, you have to have a plan in your head. 'Do I have any cigarettes?' 'Do I need to go out and buy them?' It truly frees up so much of your time. And I don't have to worry about it anymore." In addition, he no longer feels the social isolation he once did. "I would go to a meeting and be the only smoker in a room of 30 people. I was uncomfortable," he said.

Although he had tried to quit before -- and once succeeded -- my father says that this time he feels differently about abstaining from cigarettes. "I had tried off-and-on for the past 10 years, two or three days at a time. I knew I was never serious before. When I finally decided to do it, no question, I was serious. Absolutely. In my mind, I said, 'I am going to make it,' " he said. "When I knew I was going to quit, I dedicated my quitting to my six grandchildren."

But, as my father discovered, even exercise has its risks. Last month, while bicycling a block from his house, he was hit by a car and broke his left leg and banged up his face. He's off the bike until Christmas. The good news, he says, is that "not once" in two stressful days in the emergency room and doctor's office did he want a cigarette. "I'm cured," he laughed.