Paris balancing act: the fastest--and gayest--way to experience the city is at night on Rollerblades.

So what if it was my first time in Paris and my knowledge of French is about as substantial as a croissant? And should it matter that my previous Rollerblading experience comprised two tottery hours on rental skates? I'd heard that Friday Night Fever, a weekly Rollerblading whirl through Paris that regularly draws 10,000 bladers, attracts a significant gay contingent and often becomes an aerobic flirtfest. On this sultry June night before Paris's gay pride celebration, my main concern was determining whom to cruise, given that to my untrained American eye "gay" and "French" are virtually indistinguishable.

The men in the crowd in front of the Montparnasse Tower were slim, tanned, and sapphire-eyed. Despite the late-June heat--and the prospect of three hours of strenuous exercise-almost nobody had committed the sartorial faux pas of wearing short pants (except for me). Still trying to get my sexual bearings, I scanned the gorgeous legions but was distracted by all the teenage boys who looked too young yet to have fully reckoned with an orientation.

At the stroke of 10, the skaters flash-flooded onto Rue de Depart, and I was swept into the torrent--downhill. I braked and was bumped from behind. I released and hurtled forward. I wind-milled my arms. I dodged a curb. I'd have cried for help, but I lost all sense of language.

"Allez! Allez!" came a taunt from behind.

"A la droit," yelled a whizzing blur to my left.

Skate officials in yellow shirts herded the pack. And somehow I was rolling and yawing and not quite falling, and my vision was reduced to a hazy frazzle. My calves were on fire, my clothes drenched with sweat. If I'd tried to stop, I would have been steamrolled.

After half an hour of scrabbling survival, I caught a break when the throng paused to let stragglers catch up. My vision cleared just enough to see a squad of policemen, themselves on Rollerblades, slaloming authoritatively on the mob's edge. In both directions stretched an undulating swarm.

The race resumed, taking us through cobblestoned plazas that nearly knocked my teeth out and along streets crisscrossed by utility cables that I negotiated like trip wires. I still couldn't gather my wits enough to look at the scenery, but I finally managed glimpses at my fellow bladers. A good number were pumping as hard as I, but others were laughing, playing high-speed games of tag. I saw one guy guzzling a bottle of beer, another puffing happily on a joint. A dozen skaters passed me gabbing on their cell phones.

It dawned on me that this massive chase on skates was akin to driving the Los Angeles freeways, where the bumper-to-bumper traffic moves at 70 miles per hour; riding your brakes is more dangerous than keeping pace. I quit worrying about how to stop short if I had to, quit worrying about what people might think if I toppled, and gave myself over to trust. We turned a corner then, and I saw for the first time outside of a movie the shocking solendor of the Eiffel Tower: magnesium bright, fizzing like a giant Fourth of July sparkler.

Having hurtled full-speed for an hour and a half--and for nearly 10 miles--we'd finally earned a midpoint pause. The horde overtook the vast slope in front of the Chaillot Palace, with its commanding view of the Seine and the tower beyond. Hotdoggers flaunted skating tricks while the rest of us gladly rested. Water bottles were shared with quiet fratemite.

Though I looked closely, I couldn't discern any overt sexual current among the crowd. Most skaters were in pairs or groups of friends, and when one guy disrobed to a lame G-string and dove into the pool of the stylish art deco fountain, the hoots he elicited were more jocular than salacious.

After 15 minutes we were off again, and now--past the point of exhaustion but buoyed by the communal fervor--I saw everything with a dream's magnified lucidity: the Champ de Mars park, the Ecole Militaire, Les Invalides. Coming to the ski slope-steep decline into the tunnel beneath the Tuileries, I crouched into my best Jean-Claude Killy tuck and schussed at personality altering speed. (The Web site for Part Roller, the group that runs Friday Night Fever, boasts of skater speeds up to 40 miles per hour--and I don't doubt that figure.)

We rushed up Avenue de l'Opera to the lavish marble-and-gold theater that the Phantom used to haunt. We passed Pompidou Center (the inside-outness of which seemed an architectural manifestation of my emotional state), then the City Hall, home of Paris's openly gay mayor, Bernard Delanoe, who had hung on its facade a massive banner in honor of gay pride.

Crossing the lie de la Cite, we swooped in front of Notre Dame, then holy-helled it the last mile and more to the finish. When we arrived back at our starting point, the clock on the Montparnasse railway station showed exactly 1 A.M. A blister on my little toe had popped, and it felt as though a blister on my brain had popped as well. Call it adrenaline or endorphins--or the thrill of cutting your safety ropes and discovering that you don't fall, only soar--but I was sky-high and utterly clarified. In Paris's passing blur I found sharp focus.

ESSENTIALS

Friday Night Fever takes place every Friday of the year (weather permitting), 10 P.M. until 1 A.M, Participants gather at 9:45 in the plaza between Montparnasse railway station and Moatparnasse Tower. The skate starts and ends at Montparnasse station, but the route--which averages 15-plus miles--changes weekly. On Thursdays, the following day's itinerary is posted on the multilingual Pari Roller Web site (www.pad-roller.com); phone [phone].

Equipment

The best place to rent Rollerblades and related equipment Is Nomades Roller Shop (37 Boulevard Bourdon; phone [phone]). You can also get lessons there--not a bad idea when it comes to competing with the hordes of expert bladers who turn out for Friday Night Fever.

what you need

A backpack to carry your shoes, an extra pair of socks, Band-Aids in case of blisters, and enough water and snacks to help you last through three hours of vigorous exercise. Also, since the subway will have stopped running by the time you're done, bring cash for a taxi to your hotel.

what if you're a beginner?

Even though Friday Night Fever attracts mostly accomplished Rollerbladers, If you're willing to wobble in front of strangers, don't he shy about joining in. A similar group skate--for people of all skill levels, attracting a more families-and-kids crowd--leaves every Sunday at 2:30 P.M. from Place de la Bastille. Rollers and Coquillages, the organizing group, can be reached via www.rollers-coquillages.org, or by telephone at [phone].

MICHAEL LOWENTHAL is what you might call a natural athlete. Prior to our sending him to Paris to write a story about Rollerblading (page 48) through the city at night, he had never put on a pair of in-line skates. Lowenthal is the author of the novels Avoidance and The Same Embrace.