I found Bikram yoga a year or so ago, when one of the cultishly trendy, tropically hot new studios opened near my apartment in San Francisco. Maybe it was the heat, which made it easier for me to stretch; maybe it was the conviction with which the instructors recommended the half-locust pose (lie face down on top of your arms, with your palms against the floor) to ease stressed arms. But after a few 90-minute sessions, I couldn't imagine life without a bottle of water and the superheated corpse pose. I knew I would find Bikram when I got to Baltimore, but I didn't want to miss class in the stretch of days when I was wedging my body behind a steering wheel.
Mr. Choudhury practices his discipline in Beverly Hills, and urban sophisticates have come to think of his yoga as their own. Wouldn't I have trouble finding it in that vast space between the coasts?
By the time I set out in my 1984 Saab on a crisp, sunny San Francisco day, I knew I needn't have worried. A little research had turned up Bikram yoga not only in many major cities but in places like Parkersburg, W. Va., and Iowa City. A handful of states are still without the sweat-strain-and-laugh experience described on the Bikram Web site, but the practice has migrated far from California and New York, borne on the wings of Mr. Choudhury's cheerful enthusiasm and his evolving business plan. Opening at a rate of five a week, hundreds of certified Bikram studios are now operating across the United States. Others are in Canada, Europe, Japan and Australia. Mr. Choudhury is in the process of franchising the Bikram's Yoga College of India brand.
Dropping in on a class is not difficult. ''One of the great things about Bikram is they've standardized it, so you know what you're getting anywhere you go, '' said John Minnick, 63, an accountant in San Diego who visits far-flung studios when he travels.
The standardization is part of Mr. Choudhury's vision, as he explained to me when I reached him at his Los Angeles headquarters for a telephone interview. ''If you want a 2002 Cadillac Eldorado, '' he said, ''it doesn't matter which dealership you go to - you'll get exactly the same car.'' (Mr. Choudhury, who is often seen in one of his several Rolls-Royces, is fond of automobile metaphors.) To help ensure uniformity in the classes taught under his name, he has copyrighted not only his posture series but the dialogue that goes with it.
My first experience of heartland Bikram came 13 hours into my trip, and I was ready for it. The familiar aches and pains of marathon driving had set in. I found the studio in a shopping center next to a parking lot in Salt Lake City, in the shadow of a Barnes & Noble and a Bed Bath & Beyond. So much for any fantasies of yoga masters in a silent mountain hideaway, surrounded by gardens.
Inside, the studio's slick carpeted-and-mirrored look was reassuringly (if eerily) similar to what I had left behind in San Francisco. The temperature was the familiar 100-plus degrees. But only a handful of people were at this midmorning class. At my neighborhood studio, only a 6 a.m. class would have been this small. And while the students were serious and suited up in spandex, they were clearly older than the late-20's, early-30's groups in San Francisco.
But comfort came. I was soon absorbed by the familiar exhortations to ''English bulldog determination'' and physical discipline. ''Lock your knee - concrete, solid like a lamp post! You have no left knee!''
I drove out of town refreshed, cured of the stiffness that I had woken with in my hotel bed that morning.
Two days later I was in Omaha, doing the eagle pose (which involves twisting your arms around each other, wrapping one leg over the other and squatting, balanced on one foot) in a packed class with a median age considerably higher than what I was used to. I had reached Bikram Yoga Omaha, on the ground floor of a two-story office building that also houses a radio station and a Cox Cable payment center, after a Saturday morning drive that took me through the deserted weekend downtown and past the Mutual of Omaha building, a high school, and Dodge Street's distinctly unmeditative tiered commercial buildings.
The Omaha students were clearly enthusiastic about their yoga. But their grunts, groans and under-the-breath commentary suggested a discipline not quite equal to that of the take-this-seriously Bikram practitioners I knew. When I mentioned the demographic of the class in a later telephone interview with Tippi Denenberg, who opened Bikram Yoga Omaha two and a half years ago, she asked where I had been practicing. I said San Francisco. ''Ah, '' she said knowingly, ''the hot-body crowd.''
Ms. Denenberg said that ''not one person in Omaha knew about Bikram when I opened my studio, '' but that ''sure enough, in Omaha people are just like people everywhere, they know a good thing when they see it.'' She added: ''Omaha is a perfect fit for yoga. Think about it. Om-a-ha!''
In Chicago, it was back to the hot-body crowd. The light-filled, minimalist-chic hardwood-floored studio I visited in the trendy Wicker Park section overlooks crowded, urban North Milwaukee Street, home to nightclubs, up-and-coming cafes and a John Fluevog designer shoe shop. The students, mostly women in their 20's, moved smoothly into the postures and wore sporty yoga outfits.
John Marcoux, the studio's director, quit his job as a lawyer in Dallas a year and a half ago and drove to the Bikram teacher training center in Los Angeles, visiting Bikram studios along the way. ''It's a beautiful world, '' Mr. Marcoux said as he recalled the trip.
''In every city you can drive into Denny's, '' he said. ''You don't see the city that way. But when you share a Bikram class with the locals, at the end you're all dripping with sweat, and it breaks down all the normal small-talk barriers. You can really rap.''
You can also alleviate the leg cramps and neck stiffness brought on by eight hours of driving. Not only did my Bikram stops help keep me going without pain, but I recovered from the car trip almost immediately when I got to Baltimore.
Once there, I sought out Bikram Yoga of Baltimore. It opened last July, in a shopping center outside the city, alongside a Blockbuster Video, a Food Lion grocery and a dollar store, and within easy reach of several gas stations.