ON SUNDAY morning, while others are conscientiously laboring through this newspaper, I am somewhere else, enjoying myself. I ride a bike through Rock Creek Park, usually to the river and back on the easy little asphalt trail alongside the creek.

There are no monster hills and the course is serene enough for one who wants a little exercise, but not much. Rock Creek Park on Sunday mornings is one of the capital's splendid secrets, shared only by the solitary bikers and joggers who go there. We derive an easy sense of virtue from our aloneness in the park, running and pedaling or just dawdling by the creek, while the rest of the city struggles through the world's important problems.

Along the bike trail, people say "good morning" to one another. It's not required, but it happens regularly. This is the only place I know of in Washington where people say "good morning" (or don't say it) without any sense of obligation. Some of us look pretty silly, while others are obviously experts at exercise. Nobody laughs at others, but it's okay to smile.

I used to read everything in the Sunday papers, an obligation assumed by people who work for one. Then I discovered what I call the Bigart Rule. Until his retirement, Homer Bigart of The New York Times was one of the legendary trench reporters, a man who covered every bloody war and upheaval known to the last 40 years of history. Bigart was still slogging in his sixties, still covering daily deadline stories, and I asked him why he lasted so long.

Because I never read my copy in print, he explained. That way you never find out what the bastards did to it. It makes life more pleasant not to know.

I adopted the Bigart Rule and it worked. Life became more pleasant. I never see, in print, what editors do to my precious words. I never see the typographical errors. Best of all, I never have to confront my own mistakes, which somehow are much easier to spot once the story is published. No use stewing over spilled milk, as my own father would put it.

Eventually, I took the Bigart Rule a step further. If it makes life more pleasant to avoid reading my own stories in the newspaper, it also helps not to read many other stores, too. My enjoyment of the newspaper increased enormously, as I selectively read less of it. Maybe this is something normal people always knew, in any newsroom it will sound like treason.

In Rock Creek Park, my favorite stretch is the long winding road that the Park Service closes to cars on Sunday mornings, between Military Road and Broad Branch. The rushing creek is on one side, water crashing around gleaming wet boulders and over ancient rock ledges, like a stream in the mountains. On the other side, the steep hillside is covered with rhododendron and laurel and the scrub trees of a second-growth forest, getting old again.

Rock Creek Park is narrow at this point, but the illusion of woodland escape is complete and powerful. No cars on the road, no houses in sight along the ridge. Only a rushing creek in a cool forest glen, moist and clean like new ferns. Alone, on a wet morning, it is possible to imagine briefly that I am biking through a mountain ravine in eastern Kentucky or perhaps the Great Smokey Mountains, not through the ribbon park surrounded by city. Strangely enough, although I have done this many times, it always makes me feel virtuous, as though I have accomplished something, though I can't say what.

At Pierce Mill, the asphalt bike trail resumes and the Sunday morning crowd gets thicker, pleasantly. It's an interesting mix from the city: white and black and Hispanic, young and old and overweight. Last weekend, in the rainstorm, the serious joggers waited under the overpasses, jogging in place and keeping dry while they waited for the rain to stop. The loons pushed on through the rain and we got soaked. Each to his own pleasures.

As it proceeds toward the Potomac, the bike trail dips back and forth across the creek, in and out of the woods. Below the Calvert Street hill, the serious athletes gather to exercise on the course of Perrier wood blocks, hopping, jumping, stretching. I was offended at first by the humorless instructions - do this, do that - but now I like to sit against a tree and watch. I enjoy witnessing innocent fanaticism and the athletes feel superior, watching me lazily watching them.

Near the river, the same thought always occurs to me: Extraordinary, isn't it, to bike across the nation's capital on a quiet Sunday morning, through the woods, and arrive at the banks of the Potomac River, upstream from the Lincoln Memorial. The riverscape reveals the city again. After the sweet dampness of the woods, the air seems heavy and dead. Upstream, the bluffs of Georgetown are covered with bricks and glass, smokestacks, wires, towers, moving shiny objects.

The return trip has no surprises, of course. Sometimes, I stop for a minute at the zoo, where young families with babies in strollers are streaming in. The zoo is their Sunday morning escape, as the park is mine.

By the zoo, where the park road goes through the tunnel, the creek takes off on its own and makes a long private bend through the woods. The trail follows the creek, another favorite place of mine. I was riding through that stretch a couple of weeks ago when I heard a small voice crying from the creek bank.

Help. Down the steep bank, a young woman in jogging clothes was lying in the rocks, covered with blood. She blinked up at me with that stunned, helpless expression of someone who's lost her glasses. Blood was matted in her hair and streaming down her face, blood spattered on her yellow shirt like crazy finger-painting. Are you all right? Yes. Help.

"He didn't rape me," she said, as another man and I helped her up and found her glasses. This was said so triumphantly I was shocked. I thought she had stumbled at a narrow stretch in the path, but it wasn't an accident. A man in a green jogging suit followed her on the trail and, at the steepest point, he came alongside and pushed her down the bank.

Random and vicious. The young woman was trembling, but she insisted she was all right. She always trembled after long runs, she said.

The green jogger was gone, of course, vanished in the cool woods like a sick phantom. Did I pass him on the trail?Did we say "good morning?"

The police came and helped her home. I had nothing more to do but pedal onwards myself, distracted, watching for a man in a green jogging suit.

When I got home, I didn't tell my family or anyone else. Why frighten people about the park, when the park is really as safe as any other part of the city, maybe safer? That is what I told myself, but I knew the reason was slightly more selfish. If there is a green jogger stalking my private woods, that diminishes my Sunday morning feelings of virtue. The green jogger, I have to admit, reminds me of the stories I chose not to read in the newspaper.