Choudhury's method has its critics. Some medical professionals claim that it can increase the risk of cartilage tears and stress the heart. There's also the obvious danger of heatstroke and dehydration. In San Diego, a medical tent is set up not far from the main practice area for students who vomit, suffer seizures, or pass out during sessions.

Others object to Choudhury's decision in 2002 to patent his sequence of 26 postures and two breathing exercises, which has made him very rich (all Bikram studios must pay a licensing fee to open, along with a new, much-protested monthly fee) and, in the eyes of many, an apostate. Yoga is thought to date back 5,000 years, and for Hindus, claiming it as intellectual property is akin in Christian terms to copyrighting the Lord's Prayer. "Call it exercise. Call it a good workout. Call it what you like," says Dr. Aseem Shukla, cofounder of the Hindu American Foundation. "But don't call it yoga. It's a cynical appropriation of Hinduism."

But Choudhury, whose classes have attracted more than 3 million people, has his defenders. Bikram Yoga "is certainly focused on the body," says Stefanie Syman, author of The Subtle Body: The Story of Yoga in America. "But changes in the body can result in deeper, more spiritual changes. There's room for all different kinds of yoga." And from the beginning, Choudhury has been helped by friends in high places. Richard Nixon, a "good friend," was an early pupil. "That's how I get my visa!" Choudhury says. Soon, athletes like Kareem Abdul-Jabbar and John McEnroe began approaching him. "They all say, 'Bikram, you must give me one more year, please! Let me play for one more year!' I give them 10 more years!" (This is not exactly correct. Choudhury has a penchant for hyperbole.)

YOGIS IN HEAT: Male students often find themselves stimulated by positions like bhujangasana, the cobra pose, in unexpected ways.

Today, he's Hollywood's guru of choice, with followers like Madonna, Ashton Kutcher and Demi Moore, Lady Gaga, George Clooney, and Kobe Bryant. These endorsements have helped him peddle Bikram-branded products, including books, CDs, DVDs, apparel, towels, mats, and water bottles. Besides charging for teacher training and studio licensing, he also generates revenue from fees for regional Bikram Yoga tournaments that produce a national champion each year. And he's looking for ways to expand his empire: He's in talks with several U.S. cable networks about a reality show, and Sun, an Indian company, wants to launch an all-Bikram channel. There are also plans for a satellite-radio show and a magazine. He's even campaigning to get yoga recognized as an Olympic sport.

And with the client list comes a Hollywood lifestyle that has drawn criticism from rival gurus for being insufficiently modest. Choudhury owns an 8,000-square-foot mansion in Beverly Hills and a fleet of more than 40 Rolls-Royces and Bentleys. He wears a million-dollar diamond-and-ruby-encrusted Franck Muller watch. "In America we like all of our spiritual leaders to come straight from central casting," says Robert Love, author of The Great Oom: The Improbable Birth of Yoga in America. "We want them to be poor, to be sexually ascetic, to be perfectly pure, to be almost inhuman. But in reality, few of them are that way."

Choudhury has other quirks too. He says he eats a single meal a day (chicken or beef, no fruit or vegetables), drinks only water and Coke, and needs only two hours of sleep a night. Then there are the stories about him having sex with his students. When I ask him about this, he doesn't deny it—he claims they blackmail him: "Only when they give me no choice! If they say to me, 'Boss, you must fuck me or I will kill myself,' then I do it! Think if I don't! The karma!" Whatever the nature of his dalliances, his appeal to women is obvious—and a common trait among spiritual leaders, as Love points out: "When Swami Vivekananda"—another key figure in the spread of yoga to the West—"toured the U.S. at the end of the 19th century, it was the same way. Mostly women showed up for his lectures." And after Indian mysticism became popular in the West in the sixties, a new wave of gurus emerged, like Acharya Rajneesh, who evinced a radically open attitude toward sexuality.

The entire resort throbs with the libidinal energy of Choudhury's followers. They're everywhere: in line at the ice machine, under the thatched umbrellas at the restaurant, stretching in front of the mirrors by the elevators. The other hotel guests eye them. As one session ends, two middle-aged, beer-bellied guys in baseball caps pull up chairs to smoke cigars and watch the girls as they file out of the tent.

Female instructors laugh about the erections created by the pulmonary effects of some seated postures. "At times I can't even look at the men," says Mollie Glicksberg, a teacher who is getting recertified. "There's a swollen penis, jumping out at me. I don't know whether to laugh or run away screaming."

That hard-core yoga would stimulate sexual appetites seems obvious. But the practice's Tantric aspects have long been taboo, thanks to the influence of Christian missionaries in India. Officially, hookups are forbidden at teacher training. "I tell them all, 'No touchy-touchy, no kissy-kissy, no fucky-fucky!' " Choudhury says. But everyone knows better.