It was bound to happen eventually. With the growing popularity and commercialization of yoga, it was only a matter of time before someone figured out how to turn a practice that features sexually alluring young women toning their butts in skin-tight gym clothes into a hard-core porn industry.

In fact, some would say that yoga has been teetering close to soft-core porn for years. In 2006, Aaron Star struck upon the idea for "Naked Yoga," ostensibly as a way of bringing gay men in big cities like New York and Los Angeles into the yoga mainstream, by tailoring the studio environment to the gay culture's "cruising" scene. The concept has caught on, and includes some straight venues, and websites like yogaundressed.com, as well as naked yoga geared specifically to couples. Officially, sex is discouraged in Naked Yoga, but unofficially Star says "it's meant to be a turn on," and classes include extensive body contact that is so intimate that it might as well be sex, though no genital stimulation, let alone full-scale intercourse, is permitted.

The proliferation of Naked Yoga, one of the industry's better kept secrets, it seems, has gone hand-in-hand with a far more public shift toward nude and semi-nude advertising featuring yoga models like Kathryn Budig, who's posed in the buff (with her body "parts" hidden) for Toe Sox, the boutique clothing manufacturer that claims her as a spokeswoman. Budig recently received a flattering profile as an up-and-coming yoga entrepreneur in Forbes, and has already put together a nude erotic calendar that illustrates her performing a number of advanced yoga poses, this time without the socks. She's gone on to promote industry's latest pop sensation, the Thai-born Briohny Smyth, a former child actress who recently appeared in skimpy black lace panties in one of the first web videos devoted exclusively to promoting yoga's new erotic "expressionism." The 3-minute video, which includes no words or explanations, was paid for by Equinox, a super-elite, Manhattan-based fitness company that's been gobbling up smaller exercise chains nationwide and that recently announced plans to set up studios throughout Europe.

Budig and Smyth, in fact, seem destined to become part of a new yoga celebrity "stratosphere," hob-nobbing with senior executives at Equinox and at the posh apparel company Lululemon, which likewise caters to high-end suburban white women whose disposable income has cushioned them from the effects of the current recession. Among marketers this demographic has been dubbed "Lifestyles of Health and Sustainability," or LOHAS, for short. It's meant to meld the fruit and crunchy granola set, concerned about the fate of the environment, and anxious to preserve its alternative lifestyle, with the mainstream fashion and beauty consumer.

"Of course, not all of the women being recruited as a new breed of corporate "show girl" are quite so oriented to erotic glamor as Budig and Smyth are. Elena Brower, a former top aide to John Friend, the disgraced ex-CEO of Anusara Yoga who fell from grace during a major sex scandal earlier this year, is a spokeswoman for Adidas but apparently still finds time to teach yoga -- or a reasonable facsimile of it -- as part of her expanding life coach business. Another rising star is former drug addict Seane Corn, who flaks for Lucy Active Wear, one of Lululemon's low-end competitors. Corne promotes herself as a progressive political activist and yoga "purist" of sorts, which, in theory should place her at odds with elite companies like Lulu that treat yoga more as a sales prop than a wellness practice. But, in fact, she's merely the "socially responsible" face of an industry that's fast becoming the spiritual avatar of global capitalism, much as Coca-Cola and McDonald's once spread the gospel of American democracy and the virtues of benevolent empire.

Which brings us to the "bad girls" of the burgeoning hard-core yoga porn industry. One might think that the proliferation of videos with nude women performing far less complicated yoga poses than Budig's or Smyth's -- then transitioning into graphic sex acts -- would pose a major threat to Yoga, Inc.'s quest for mainstream acceptance. But if it does, there's been no audible hue and cry from industry big-wigs, or even from self-proclaimed yoga "purists" who seem as titillated by the underlying sexual dimensions of yoga as the industry "sell-outs" they so frequently chastise.

In fact, the yoga industry seems to have acquired its new porn fetish in stages. In addition to Naked Yoga, another key milestone was the decision by Playboy magazine in 2008 to promote one of its nude models, Sara Jean Underwood, as a full-fledged Yoga "playmate." Underwood, who has since starred in a series of slickly produced yoga "instructional videos," seems to be playing the part of a real-live yoga "teacher," In fact, she is largely going through the motions, and while she does correctly identify the names of some of the yoga poses that she demonstrates, her postures are often embarrassingly imprecise. And like the new yoga porn stars, she performs in her videos completely nude, sometimes in graphic close-up, and seems to delight in titillating her viewers at every turn.

Still, there's one big difference. While there's full frontal nudity in the Playboy videos, there's no actual sex. Underwood, in fact, always appears alone, and she does stick to the semblance of an instructional "script." No men suddenly appear on camera while her body's provocatively splayed in "Wheel Pose" to push their erect penis into her mouth. She may not be offering much in the way of spiritual stimulation, but she's no vulgar exhibitionist, either. Her videos seem more designed to suggest that Playboy is keeping up on the latest health and fitness trends, and may actually have some regard for the physical welfare of its models, rather than treating them as mere sex objects. As absurd as that seems given the hyper-sexual context of the videos, one does gets the impression that Underwood is actually trying -- her glossy makeup, bikini-waxed legs, and utterly hairless vagina, notwithstanding.

But does it really matter? While women may enjoy these videos, too, it's clearly the male consumer that is the primary target of the emerging yoga sex campaign. Men, by a more than 2-1 margin, are the more avid consumers of commercial porn, and of course, from Playboy's very inception, they've also been the key demographic targeted by the magazine. So, in fact, a subtle and still largely imperceptible -- and certainly unremarked -- shift may be underway in the yoga market, which, according to market research reports, has hit something of a wall among female consumers. They're buying more yoga-related products than ever -- at double the gross revenue level of five years ago -- but the total number of consumers appears to have flat-lined. Women continue to be the most active and attractive names and faces around which the yoga industry is most visibly promoted, but the market clearly needs fresh blood -- and increasingly that blood is male.

In other words, yoga, which has hitherto catered to women by a 3-1 margin, may have finally found a way to reach consumers with penises. Less as avid yoga practitioners in the full-fledged lifestyle sense, perhaps -- though male yogis or "brogis" are slowly emerging, too -- than as highly specialized consumers in selected venues. But make no mistake: this is no mere niche male market. There are nearly 4 million active-duty soldiers and nearly 24 million military war veterans, mostly men, and together with their families, they constitute roughly 10 percent of the total U.S. populace. And there are an estimated 40 million Americans who access an internet porn site daily, most of them men, too, though according to some estimates, a growing proportion, 30 percent, or 12 million -- roughly equal to the size of the current U.S. yoga market -- are now women (one of the reasons for the rise of lesbian yoga porn, perhaps).

This is "yoga for the masses," alright, on a hitherto unknown scale. For a few good men, and for lots of devilish ones, too. And anyone else, apparently, who's open to yoga's sprawling -- if not unseemly -- commercial orgy.