My religious conversion to the muscle-magazine mind-set occurred in the middle of an Albertsons supermarket 10 months ago.

I had usually ignored men's magazines, but as I perused the magazine shelves, this one had an irresistible allure. Its cover featured a healthy, bright-faced youth, wearing nothing but a Speedo -- and a nicely bulging Speedo at that. He was shown emerging from a pool with a look on his face of absolute joy. Water dripped down his glorious, muscular body. He seemed to me the most gorgeous specimen of masculinity I had ever seen. Sort of like a young Tom Cruise, but sexier and with a less prominent nose. I quickly looked to see if the magazine's contents lived up to its cover. Indeed, they did. Page after page of male heat sizzled inside. Posing, sweating, getting physical. Men! Men! Men! I could feel my temperature rise.

Had I found the magazine Burn! Real Fitness for Real Men at a gay bookstore I wouldn't have been surprised, but at the local grocery market? That bastion of homogenous, middle-class, suburban heterosexual culture? What would Dr. Laura say? Though Burn! was disguised as just another fitness magazine, I blushed as I handed it to the clerk at the checkout stand. I knew it was much more than a fitness magazine.

It was pornographic, and it turned me on.

Available at most any newsstand, muscle magazines are homoerotic pornography for the masses. Their appeal seems to cross sexual orientations. Straight, gay and bisexual men have been known to enjoy them. In their pages, they eroticize both the flesh and the culture of men. To read them is to be sexually seduced into a fraternity to which all men are invited. They unite their readers in a kind of sexually charged adulation of masculinity. To the cult of testosterone in America, they have an almost biblical authority. They give direction, in the most literal ways, on how to be the ideal man: "Do this exercise, take this supplement, play this sport and you will be just like the men in these pages."

When Richard Perez-Feria founded Gym and Burn! magazines in 1998 he believed there was a void in the so-called men's fitness market for publications dealing with the lifestyle of men who enjoy working out. His instinct proved correct. They became huge hits. This month, approximately 300,000 copies of each title were distributed to newsstands nationwide. While the Audit Bureau of Circulations has not released paid circulation numbers for the magazines, Perez-Feria says they have averaged a 35 percent sell-through on newsstands. And Muscle & Fitness boasts a paid circulation of almost 500,000.

Having sold the magazines to a publisher a few months ago, Perez-Feria will soon launch a similar one called Tough, fully expecting it to be a hit as well. He says he wasn't surprised by the success. Instead, "I was surprised at the intensity and the quickness ... and near fanaticism which I got."

He received thousands of positive e-mails, letters and phone calls from readers. "There was such passion behind it. The readers were so excited about the magazine. The intensity ... and devotion to the magazine was incredible."

Several of these letters appeared in the magazines. The writers represented a wide spectrum of masculinity, from married men in the suburbs to college frat boys to guys who are openly gay. Someone wrote in to admit that the models were so hot that both he and his wife were turned on by them.

While at first I thought this to be a new trend -- fitness magazines doubling as homoerotic porn -- I soon discovered it's an old practice that's undergoing an intense revival.

The first muscle magazine was published in Germany in 1893, followed five years later by two similar English language publications titled Physical Culture and Physical Development. Over the past 100 years, muscle magazines have taken many forms, but a historical overview of the genre shows that, at least until the 1960s, they served mostly as alibis for men to be able to look at pictures of other men, either nude or semi-nude, with little risk of scandal.

In his book "Hard to Imagine: Gay Male Eroticism in Photography and Film From Their Beginnings to Stonewall," Thomas Waugh demonstrates that the poses of the models, the gay ghetto codes used in the captions and advertisements, and the letters readers sent to the editors all point to a deliberate but secretive homoeroticism in muscle magazines throughout the first half of the 20th century.

He even claims that, "In terms of impact as well as artistry, the current of physique eroticism that flourished in the postwar decades is one of the great achievements of gay culture."

Is it true, then, that the typical muscle magazine on the market, read by men from all walks of life, including the most macho, hulking, heterosexual of figures, has its roots in gay culture? This may come as a surprise now, but the public started to catch on to it in the 1950s.

This new awareness was exemplified by the House of Representatives' gathering committee on current pornographic materials, which, in 1952, railed against "Nudist magazines and those which pandered to homosexuals by depicting 'the male body beautiful.'"

In 1958, a model writing in Iron Man magazine said he was disgusted by the realization that he and other bodybuilders were being ogled by men "with perverted sex interests." Something had to be done about this, and it was. An intentional split occurred in the muscle magazine trade between those serving a straight readership and those of a gay readership (or closeted gay readership).

Magazines arose strictly for "real" bodybuilders, a category that still exists. In these, publishers bypass the homoerotic beefcake imagery, and feature articles on training, diet and competitions instead. The photography is dull and lifeless. The men, invariably pictured gripping some huge weight, always look very pained and not at all sexy. (Or rarely even human, for that matter. The physical ideal seems to be that of the Incredible Hulk without the green skin.) It's easy to spot these magazines, as their covers usually feature some muscular version of Pamela Anderson Lee -- further enticement, presumably, to a heterosexual male reader.

There are no women on the cover of Burn!, or anywhere inside. Nor will you find them in Gym, its sister publication. Other exclusively male magazines are Exercise for Men Only, and Men's Workout. It seems that readers of these magazines aren't interested in the female form. What are they interested in, then? For whom are these magazines intended?

This is an issue someone raised in a letter to Burn! last year. He wrote, "I'm not sure who your audience is, despite the tag line ('Real Fitness for Real Men'). I would hate to see such a wonderful magazine get blacklisted by anally retentive, unaccepting individuals. It could happen to Tinky Winky, it could happen to Burn!"

Richard Perez-Feria estimates that when he was editing Gym and Burn!, which was when they were most erotically charged, the readership was evenly divided between gay and straight men, though the boundaries between gay and straight seem to be blurred in this case.

"It's a very open secret among the magazines that are in the market that you're basically creating a magazine for, we call it a 'closet case reader,'" he explained. "A guy in St. Louis or Alabama who doesn't get a chance to look at men openly, or enough men as he wants to look at. And so you wrap it around the fitness context. You put a hot guy, oiled down with a dumbbell, on the cover like Men's Workout does, and they do all the phone sex ads in the back, and you have a magazine. It's a healthy magazine that will have 100,000 or so readers that just can't get that stuff anywhere else, so they'll buy it. And so Suzy the girlfriend or wife or mother thinks it's a fitness magazine, when in fact -- wink, wink -- they know it's something else."

There was a lot of winking going on in the Gym cover story about Baywatch hunk Michael Bergin. The August 1999 issue featured an interview with him and made playful references to his sexual preference. Was he straight? Was he bi? He claimed the former, but one had to wonder about the latter. Suggestive photos of a semi-nude Bergin surely aroused even the most jaded pornographic fan. The pepperoni on the nipple shot was my favorite.

In a few of the photos, Bergin seems to resemble the late John F. Kennedy Jr., which is interesting because Bergin claims to have proposed marriage to Carolyn Bessette twice before she married Kennedy.

Oh, if only Kennedy had graced the pages of these magazines! Especially as he appeared in his 20s, he would have been a marvelous model for either Burn! or Gym. To my mind, the young men of these pages, with their bodies so elegantly muscled, resemble the long, lean figures of Lysippus, the great pre-Hellenistic sculptor. They are living works of art. Neither bulky nor skinny, they are perfectly balanced, shown in a rare, privileged moment, right at the cusp of full adult masculinity. Posed always before male photographers, wearing the tightest of underwear and no shirt, they know men watch and worship them and seem to delight in being the focus of their gaze.

The photography is intended to be erotic to men, yet the accompanying text often points out that the model is straight, by making reference to his girlfriend or wife. A typical example is the profile of competitive diver Troy Dumais, a gorgeous 19-year-old Olympic hopeful. "The first time I had sex, I was 17," he says. "It was with my girlfriend, Nicole. Man, it was so wonderful and so special in the sense that I know that I want to spend the rest of my life with her."

Photographs show Dumais modeling four different pairs of shorts, all bursting with the most promising bulge, as he gives off a lusty stare. The message seems to be that although a guy is romantically committed to being with a woman, he can still share a little "erotic play" with men. It's not sex, but it's seduction, flirtation and just a mutual enjoyment in being male.

This is illustrated by the copy for "College Muscle Jocks," a video that's advertised in several muscle magazines. "It's back to college as eight stunning, buffed-out centerfolds invite you to a skin-filled fraternity weekend of hazing, rowdiness and wild fun!" shouts the headline.

"After the secret initiation of the freshmen it's a nonstop party with workouts at the gym, towel-snapping in the showers, stripper parties at the bar and pillow fights in the dorm. Then catch each frat stud alone in a private fantasy showing off his naked muscular body just for you. Once you see these great looking college boys, you'll join the fraternity."

Other video titles include "Wide Nude World of Sports," "Naked Football League" and "Buff Bachelor Party," where "seven hunky friends celebrate the groom's last weekend of freedom with wild naked games and horseplay."

If the advertising in a magazine is an indication of its readership, as surely it must be, then the fantasy of male community, of team sports and group male bonding is obviously a very popular one. For gay men, this has long been known. Tom of Finland, one of the gay icons of the 20th century, illustrated it quite frankly. His images show an obsession with the erotic charge of male culture.

But does the average reader of these magazines realize the attraction? Of course I have no way of getting into his head, and believe me, the last thing I'm going to do is approach some strapping baseball-cap-wearing dude who's flipping through one of these things at the newsstand and ask him if the pictures make him horny, and why.

But I believe some of the readers are indeed clueless about the underlying eroticism of the publications. For instance, Perez-Feria says that his father read Gym and didn't feel it was pornographic at all. "He thought it was a bunch of guys with great bodies. He had no clue for him that it was pornographic. So, it's all how you respond to what you're looking at." I have noticed a variety of responses among heterosexual men.

Some have expressed discomfort about the semi-nudity of the models. In one issue, five young dudes (Mike, Mike, Jeff, Adam and Steve) complained about it, claiming in a jointly written letter that most guys don't want to see others in such a state. They didn't say they were canceling their subscriptions, though.

Some readers are shocked when the eroticism of muscle magazines is pointed out to them. Rob Schuh, a columnist for Testosterone, recounts that, "Conrad, a friend of mine, was over eating pizza and he started flipping through all of my bodybuilding magazines. Conrad is gay and thought that All Natural Muscular Development was geared for a gay audience. I put this question out there and received about 10 corroborating e-mails. I also gave Conrad all of my bodybuilding magazines to take home. He lives in an all-gay household. He said that all of the mags went into the garbage except for All Natural Muscular Development. His roommates stated that all the male models were in 'homoerotic' poses. They also said that the few photos of females were thrown in merely as 'cover' and that the real reason the mag was always next to the toilet with the pages stuck together had nothing to do with the women, if you catch my drift. OUCH!"

In another issue of Testosterone a reader comments, "I got a few laughs when I read the discussion sometime back about whether Muscular Development is a 'gay mag.' But take a look at Page 110 of the May 2000 issue -- this guy is obviously gay: 1) His ass is hanging out of the back of his 'hot pants.' 2) He's only squatting 135 pounds. 3) Why does he have a boner, and why is Muscular Development showing it to us?"

A spokesman for Testosterone told me, "Look, the point is, these mags simply aren't published for bodybuilders and serious athletes. I mean, do we waste our time criticizing Modern Sewing or Ladies Home Journal? Nope, they aren't made for us, so why bother. Same with some of the other 'fitness' mags out there. Just don't buy them 'em if they ain't your cup o' tea."

But they are my cup of tea. I find them much more exciting than conventional gay pornography, most of which is nothing but mindless humping and sucking. Very one-dimensional. The best muscle magazines depict men in a fraternal fashion, as "buddies," as guys you want to hang out with to watch sports on TV after a sweaty workout. But the holding back of actual sex makes for a steeping, spicy brew.

As a teen, I never fit in with male athletic culture. Like many sissy-boys in high school, I feigned illness to avoid going to the gym and the dreaded locker room. I wish I had discovered these magazines when I was a young man grappling with my attraction to and fear of men. I think Gym would have helped me work out my sexual thoughts and feelings, as others might have done on the sporting field or in the locker room.

Bruce Benderson wrote of such a person in his 1970 sex novel, "Meet Me at the Baths." His 15-year-old character, Paul, has sexual fantasies of the kind of men he had seen in muscle magazines: "Sometimes it would be a short, stocky blonde; at other times a mammoth brunette. He would speak harshly to me, telling me to get down on my knees and pay homage to the glory of his muscular body."

"The depth of reaction that people have to bodybuilders is very significant," says David Plummer, who writes about male sexuality from the University of New England, Australia. "People seem to be either gripped with desire or they are revolted. The point is that it is rare to see anybody who is simply disinterested."

Plummer speculates that narcissism is an important factor in determining why some men are "gripped with desire" when reading muscle magazines. "Narcissim tells us a lot. It is a deeply homoerotic phenomenon. It implies that, deep down, men really do know how to appreciate men." In this case it seems that narcissism is a love not only for oneself but for one's ideal self as pictured in the pages of the magazines.

Paul eventually meets up with one of these guys in real life, a "straight" jock who forces oral sex on him after gym class. Although this was rape, Paul mysteriously described the experience later as a kind of epiphany, as "the image of his powerful body in the shower, and the halo of water which bounced off his white shoulders as I knelt before him, was impossible to erase from my mind." After long immersion in the "monthly bibles" of masculinity, it was as if the young man had encountered a god.

Perhaps, then, the greatest allure muscle magazines have to men -- one that crosses boundaries of sexual identity, that goes beyond the titillation of pornography or the usefulness of fitness information -- is that they glorify masculinity. They make men feel good about being men. And the pages say to them, "You, too, can be a god."