The spine surgeon studied my MRI scan and frowned slightly. I was told the disc at L5 was bulging and degenerative. "You should not be running," he pronounced.

And just like that, I was done.

I had wondered what would finally end my running career. After 40 years, the activity was as natural to me as breathing. Like most runners, I lived for my runs. But when a spine surgeon tells you to stop, you do.

Other activities were possible: swimming laps in a pool, cycling, and in winter, Nordic skiing. My physical therapist urged me to walk, though, to retain my strength in hopes that someday I could resume what I loved best: pounding the open road for miles at a time.

On my first morning walk, I headed down a running route that took me to high land overlooking North Center Lake in Center City, Minn. At 6:30 a.m., the skies were blue, the air was cool, and bluebirds sang from the wires. As I paced, I recalled that Henry David Thoreau had written an essay about walking. I vowed to look it up when I got home.

Indeed, Mr. Thoreau had written a lot about the art of walking, which he called "sauntering," a word he claimed derived from people on pilgrimage in the Middle Ages, wandering about the countryside, "going à la Sainte Terre" — to the Holy Land — who gradually became known as "SainteTerrers"or Saunterers.

We tend to think of sauntering as rambling along at a leisurely pace — a gait I call the Rosedale Shuffle. You know what I mean: The amblers roaming the malls, gawking at shop displays, sipping soft drinks, who impede your progress as you stew impatiently behind them, trying to accomplish your mission for being in the mall, making your purchase and getting the heck out. Thoreau didn't have malls to contend with, but I almost wish he had, to hear his acerbic take on the phenomenon.

Thoreau had something much different in mind when he sauntered. He wrote of each walk as a kind of crusade in which he reconquered the hallowed land around Concord, Mass., from "the infidels."

An infidel is anyone who has a different set of beliefs from the ones you hold. Because Thoreau was a unique thinker, nearly all of Concord were infidels to him. In his essay "Walking," he noted that the deadliest weapons humans ever wielded were those that turned living nature into cultivated fields, those tools"rusted,"as he put it, "with the blood of many a meadow."

This idea of Thoreau reclaiming sacred land pleases me. I like to think of the Holy Land not as overseas or in some otherworldly future, but in the here and now. "Take off your sandals," God said to Moses as he confronted the burning bush, "for you are standing on holy ground." Moses happened to be on Mount Horeb, but he might have been anywhere, for what patch of earth are we willing to say is not holy?

On a ramble

This summer morning I sauntered off to the Holy Land of Chisago County on a road that brought me to an overlook of South Center Lake. Far in the distance, I could see Lindstrom's coffeepot water tower; nearer was Center City's water tower with its St. Lucia crown of communication antennae. I find that I am seeking out routes that I avoided as a runner, because of unpleasant hills that I didn't want to face. Hills are not an issue to a walker. In fact, they beckon because they lead to summits that offer vistas, the better to survey the Holy Land. From my house, I can walk to four different lakes in less than half an hour. Thoreau would observe, I think, that one would suffice. Only one blue eye is needed to provide perspective on a different way of living.

This morning, I heard 18 species of birds on my 3-mile walk. Robins sang, embarking on their second, if not their third, nest this season. A relaxed and raspy yellow-throated vireo called from the treetops and a querulous catbird chattered in the bushes. In the distance, crows mobbed a red-tailed hawk as it soared over a woodlot. The infidels, I'm sure, heard nothing.

I passed a small farm that is for sale this summer. An adjacent hayfield had not been cut. This cheered me. It is possible that the savannah sparrow and the bobolink that I heard singing on its edges were able to fledge at least one nest of young this breeding season. Both birds are grassland ground-nesters. Minnesota's grassland birds are not doing well these years. Too often I hear meadowlarks, savannah sparrows and bobolinks singing on wires next to hayfields that are mowed around June 1. It is not possible these birds are done with nesting that early. Their nestlings succumb to the mower. I can hardly begrudge farmers their hay, so this is a conundrum.

I'd love to know what Thoreau would have to say about it.

To make walking a worthwhile exercise, there needs to be intensity. I satisfy this requirement by altering my pace. Runners call this "doing fartleks" — fartlek being the Swedish word for "speed play." My dad, a cross-country coach, called it "running telephone poles." It is simply interspersing moderate exercise with sprints of speed. I am certain Thoreau did not do fartleks. I would love to hear his commentary, too, on the practice.

Still, like Thoreau, I aim to reclaim this land. People didn't used to drive around in automobiles. They walked the countryside and heard the sedge wrens in the ditches and the pewees in the trees. At the slower pace of a human stride, they had time to consider their place in the universe, their appropriate role in the great scheme of things.

Sue Leaf saunters in the environs of Center City.

Thoreau's essay "Walking" can be found online at bit.ly/thoreauwalk.