It is the last Sunday morning in July. I arrived in Paris well past midnight, exhausted from the long drive. The Rue de Rivoli was a madhouse, thick with tourists and revelers. I checked in and walked around for an hour to find a meal, but nothing was open. After settling for peanuts and a cold Leffe at a bistro on the Rue de la Madeleine, I hit the sack. There was no thought of a wake-up call.

It is my ritual in Paris to rise early and run along the Seine. I like the solitude of the early hour; the sifting and sorting of emotions that comes with a workout so far from home, in a city so historical and magnificent, on paths trod for centuries by peasants, soldiers, students, whores, merchants, musketeers, kings, tourists — and now runners.

But it is close to noon as I step outside my hotel. The last Sunday in July is also known to Parisians as the last day of the Tour de France. On this day, police barricades separate street from sidewalk throughout the heart of Paris, lining the route the Tour will follow this afternoon — and blocking my access to the Seine. The sidewalks are jammed with spectators saving their viewing spots, making it impossible to walk more than a few steps without stopping to squeeze through the congestion. Running is out of the question.

This is clearly a time for extreme measures.

I head back to my room.

One great perq of being a journalist at the Tour is the press credential. It not only allows access to the riders and teams, but also makes it possible to step over the barricades and onto the course itself. An ordinary spectator attempting the same maneuver would promptly be arrested.

I've been covering the bike race for three weeks, following it from city to city as it wound around France. Now, I grab my credential off the nightstand. Holding the stiff 3 x 5 piece of laminated plastic in my hand, I plunge into the crowds until I am once more pressed against a barricade. A blue-uniformed gendarme stands on the other side, arms crossed. I flash my credential, not sure whether the same rules about course access apply in frenzied Paris.

They do.

The policeman waves his hand and nods at me like we are instant friends. He beckons me to climb over. I swing one leg over the barricade, then another.

And then I am on the course, a lone runner on a broad empty boulevard, surrounded on all sides by chaos and crowds on the other side of the barricades. I break into a steady run up the sycamore-lined Champs Elysees. There are no cars, no motorcycles. Just me. The road climbs gently toward the Arc de Triomphe. Pavement was laid over its cobblestones after protesters famously hurled them at police in 1968. But here and there the blacktop is thin, and those ancient cobbles poke through.

I'm not much on runners who call attention to themselves — "stunt running," I call it. My drug of choice is solitude and my favorite runs take place without a single eyewitness. I roll my eyes at the knuckleheads who try to draw a crowd by sending out press releases touting their attempts to run 300 miles straight or 100 marathons in 100 days. But today is different. There are no trails in Paris, and no place to run but the course. Unwilling or not, I have made myself a center of attention.

I lope past the Hotel du Crillon and then up the Champs, with its trendy boutiques, jam-packed cafes and that little dirt walkway under the row of sycamores where I snapped a picture of my wife on a brisk October afternoon two years ago. In the photograph, she looks beautiful and serene, her lips and cheeks flushed from a sharp wind, bundled in an overcoat and gray scarf. Her smile is that of the Mona Lisa. She was tired. We had walked miles that day and the sun was setting. Soon we would stop for un pichet of white wine and salad with great hunks of bread and butter. But first, as the autumn sun sets, a photograph, which I later framed. It is my favorite Paris moment.

I run on.

It occurs to me that not so many years ago, the sight of a man running for no reason whatsoever would have seemed an act of lunacy — or larceny. It's safe to assume that running up the Champs Elysees on the final Sunday in July would also entail being stopped by the police and politely questioned about the motivation for this odd behavior. "Why are you running?" "What are you running from?" I can hear it now. A lone runner would have been no different than a man in a clown costume riding a unicycle.

Times have changed. The idea of running as a reverie is no longer absurd. But back when I first began thinking of myself as a runner, the sport was a secret society, misunderstood by the general populace, taunted on the roads by wolf whistles and cheers of "pick it up," and puzzled by the unplumbed mysteries of proper training diet (I consistently fueled up with Ding-Dongs, Hostess Fruit Pies, and glazed Winchell's Donuts). Back then, when running shoes and shorts made just for running did not exist, I trained in cotton t-shirts, thick tube socks and Pro-Keds. A typical race entry fee was five dollars. And instead of electronic computer chips to record finish time and place, wooden tongue depressors were handed out at the end of every race, each with a number in black Magic Marker denoting finish spot. "1" for first place, "2" for second, and so on.

It was a small world, clubby and homespun, limited in my mind to the running bastions of America and Britain. There was a special magazine for people like us. The subject matter of Runner's World wasn't the "world" in the broader context, but that very small bubble known as the running community. In this way, it was like its niche sister publications Camping World and Scuba World, pulling the reader inward to the wonders of our secret society, and in the meantime shutting out the actual world at large.

Running has since exploded (one could argue the same for camping and scuba, though not in the same numbers). The world of running — the runner's world, so to speak — is now universal. More people run than any other sport. Everyone runs or knows someone who does. There are races on each of the seven continents.

The mindset of the modern runner has expanded accordingly. In ever growing numbers, runners are taking the simple sport they practice in humble ritualistic fashion on the roads and trails of their hometown, and transport themselves thousands of miles to do it somewhere else. "Destination running" — the practice of seeing the planet by traveling to farflung marathons and other endurance races — is now a tent pole of the tourism industry. New York City's annual marathon puts more money into the city coffers than any convention or sporting event — including the World Series.

In this way, runners are modern explorers, venturing into parts of the world they do not know as part of their travel experience, while at the same time pushing their bodies into uncharted realms of discomfort and stamina during the race itself, hoping to discover a new and more empowered version of themselves.

The current running boom has swollen the number of runners in America to more than 40 million. Figure in the rest of the world and we're looking at hundreds of millions of men and women who now list running as their primary form of fitness.

What has brought this about? The nature of the sport has changed, with less emphasis on elite competition and more on participation. It is the true bastion of the Olympic ideal put forth by Pierre de Coubertin: "The important thing in the Olympic Games is not to win, but to take part; the important thing in life is not triumph, but the struggle; the essential thing is not to have conquered but to have fought well."

This does not completely explain the grown men who run half-marathons in half-naked costume as Princess Leia, but it's a start. Nowadays, finishing is more important than winning. And women, who used to be forbidden from taking part in the running world, make up a majority of the community.

Now, more than ever before, this is truly a runner's world.

And yet, running is still a uniquely individual experience. Each person personalizes their daily run in a way that makes it singular unto themselves, no matter whether they are racing alongside 35,000 strangers at the London Marathon each year in April — or me, jogging alone up the Champs Elysees in July because I need a proper sweat and there is nowhere else to run.

At the exact spot in front of the Arc de Triomphe where the riders will make a complete 180-degree turn seven hours from now, I step back over the barricades and off the course, on my way to take a leisurely running tour of Paris. I have crossed from one side of Paris to the other, thanks to my credential. Now it is time to leave the Champs.

The sun is beating down and the tourists are everywhere — the Louvre, Musee d'Orsay. Notre Dame, and on. The lines to climb the steps of the Eiffel Tower are so long that wind machines are being used to blow mist onto the throngs, lest someone pass out from heat exhaustion. 

I finish my run by hopping back over the barricades one last time and running back across the Place de la Concorde to my hotel. The moment is outrageous and unique, almost the perfect run. I have neither conquered nor triumphed, though I have definitely struggled. Yet on this day, in the most outrageous circumstances, I have run.

And that is enough.