AT AN hour when he would usually prefer to be asleep, your correspondent drags himself into an LA Fitness gym in north London. In the changing room, he finds a reassuringly fat man forlornly weighing himself; but the other early birds wrestling with the weights machines look dauntingly fit and expert. Nursing a mild hangover and grave doubts about his vocation, he prepares to meet his nemesis.

His nemesis is an affable personal trainer, who is initiating him into the cult of the gym. Questioned about his exercise regime, your correspondent mumbles something about playing soccer from time to time. The instructor is not impressed, and introduces him to a series of contraptions that look like instruments of torture. The new boy and the step-trainer do not see eye to eye. After much sweating and huffing, the instructor estimates that it will take six months for the novice to get into shape, if he eats healthily and sticks to mineral water. The pupil makes his excuses and leaves just before the “fat burner” class begins; the trainer amicably promises to take the relieved smile off his face if he shows it in the gym again.

This humiliating ordeal is of course familiar to millions. It will soon be familiar to many more: the busiest time for gym recruitment is just after Christmas, when seasonal gluttony and optimistic new-year resolutions impel the slothful to take drastic action. The other bumper recruitment times tend to be just before the summer holidays (for which people want to look nice) and just after them (when they realise that, alas, they didn't).

The fit and the saved

The modern gym craze grew out of the aerobics fad of the 1970s and 1980s. In Britain, the industry really took off in the 1990s, when private companies entered a market that had previously been dominated by local councils. Membership of private British gyms, and their revenues, more than doubled between 1996 and 2001, according to the International Health, Racquet & Sportsclub Association (IHRSA). The leading gym franchises have rapidly become fixtures in high streets and shopping arcades. The LA Fitness chain, for instance, one of the country's most successful, was founded in 1996 and will, according to Fred Turok, its chief executive, have 73 outlets by July 2003; the (relatively modest) average monthly fees are currently £38 ($58). Likewise, gym revenue in Germany has almost quadrupled in a decade.

But the beefiest market by far is in America. There are three times as many health clubs in America as there were 20 years ago; around 13% of Americans were members at the last count, and many more attend casually. Companies hoping that the odd work-out will improve their employees' productivity and perhaps contain their health-insurance bills, along with growing numbers of older recruits, have helped to sustain the boom. All this represents quite a big change in how people in rich countries—particularly the young and affluent—spend their time and money.

To anthropologists of the future, however, the gym boom may look as much like a sinister cult as a commercial triumph. Gym-going, after all, has all the basic lineaments of a religion. Its adherents are motivated by feelings of guilt, and the urge to atone for fleshly sins. Many visit their places of worship with a fanatical regularity: a third of LA Fitness members, for instance, go virtually every day. Once there, believers are led by sacerdotal instructors, who either goad them into mass ecstasy during aerobics classes, or preside over the confessional tête-à-tête of personal training. Each devotee has his own rituals, though most rely on the principles of self-mortification and delayed gratification. The extremist cult of body-building, whose Mecca is Gold's Gym in Venice, California, has become a mass movement.

After escaping from a brush with the horizontal leg press, the question that troubles this slobbish journalist is: why? What inspires the armies of devout body-worshippers? What is the point?

Today's young professionals are not the first people in history to devote so much time and cash to the cultivation of their bodies. The word “gymnasium” comes from the Greek word gumnos, meaning “naked”, which is how many ancient Greeks practised wrestling, boxing and running in their gymnasia (or palestra). Gymnasia were part of Plato's ideal city; the Romans inherited this corporeal preoccupation from the Greeks. Ancient gyms shared some features with their modern equivalents: for instance, well-heeled exercisers could engage the services of the classical version of personal trainers. There was a fair bit of ogling. But one essential difference was that one of the purposes of gym-attendance was to prepare young men for war; it was essential for the warrior classes in martial societies such as ancient Sparta.

Conventional religiosity motivated a 19th-century form of body-worship. Christianity had traditionally regarded the body as something of an embarrassment; but with the Victorian rise of “muscular Christianity”, looking after the body became a way of worshipping the creator. Christian gentlemen were obliged to attend to their muscles as well as to their minds. Exercise was also embraced to quell the unruliness of poor, urban youths, who were shepherded into boxing clubs. And it answered worries about the sturdiness of the national gene pool, which was required to generate enough able-bodied young men to govern an empire. So the cult of the body spilled out of public schools and into the slums (and across the Atlantic to America).

Unfortunately, these precedents offer little insight into the motives of today's mostly civilian, often godless gym-goers. But there is one concomitant phenomenon that might supply an obvious explanation for the rise of the fitness religion: fat. The exercise boom has coincided with an epidemic bulge in waistlines in many rich countries: an astonishing number of Europeans and Americans are either over-weight or obese. So perhaps gym-attendance can be explained as a logical consequence of gluttony—a prophylactic or remedy for fatness in particular, and a sensible way to stay healthy in general?

One problem with this neat explanation, as a visit to almost any gym will reveal, is that most gym-goers are already depressingly svelte. According to Mintel International, a British market-research firm, more people visit gyms to tone up than to lose weight. As one personal trainer confides, fat people are generally too self-conscious to subject themselves to comparison with the flabless forms of most gym users (though some clubs are attempting to entice the shy with euphemistically named “beginners' sessions”). Society, it seems, is becoming polarised between the fat and the fit.

Moreover, if better health is what the running-machine acolytes are looking for, the gym is not always the place to find it. Cardio-vascular exercise has undeniable benefits. (The calculation made by one waggish sceptic—that the amount of time exercise adds to a life is approximately equal to the amount of time spent exercising, yielding a net gain of zero—is no doubt unreliable.) Working out can, says Jeremy Shearman, a specialist in exercise psychology at Britain's University of Essex, have wider benefits, including increased productivity. However, gyms are quite often bad for their devotees' health. That is partly because, as in any gold rush, some unscrupulous entrepreneurs have cut corners on staffing, and regulations have evolved belatedly. So, in Britain, there is no industry-standard qualification for fitness instructors, who often boast only one of many more or less bogus diplomas, or none at all. Some inflict cruel and unusual punishments on their flocks. Even adherents of sedate sub-cults such as yoga are liable to have their limbs damagingly contorted by maverick instructors.

Jonathan Betser, an osteopath in Harley Street, London, says he spends much of his time treating back problems and neck strains incurred by gym-users who have been badly advised or are over-ambitious—compensating for their sedentary jobs with lunatic and damaging work-outs. Others concentrate too much on improving one particularly beloved muscle and end up with dangerously imbalanced bodies. The peak time for such self-inflicted injuries, Mr Betser says, is (be warned) during the penitential January rush.

The sweat and the stupor

Whatever they do to the body, gyms are certainly numbingly bad for your mind. This is not simply the partisan judgment of a self-vindicating slob. The biggest problem the fitness industry faces is retaining club members, who, when their original zeal wears off, get bored with all the lonely and repetitious rituals. To combat the threat of boredom, gyms have installed distracting televisions and (in the posher ones) Internet connections to entertain the Sisyphean toilers on bikes and rowing machines. Most chains have devised zany-sounding exercise classes to bedazzle flagging members. LA Fitness, like most others, offers a range of unpronounceable varieties of yoga: Astanga, Iyenga, Sivananda, and so on.

At the plusher end of the market, the techniques deployed against boredom are much more elaborate. After a generous recovery time—and a more substantial lunch than was technically advisable—this correspondent subjects himself to one such elaboration at the Third Space, a swanky gym in Soho. With membership costing around £1,000 a year, the Third Space is not quite London's priciest outfit, but is probably its most chic. He heads for the club's full-sized boxing ring for an hour's instruction with Martin, a charismatic and patient professional light welterweight. Martin assures him that learning to box is a good way to get fit (the possibility of concussion notwithstanding), and one which is surprisingly popular with women. Martin doesn't seem to mind—or perhaps he doesn't notice—when his pupil breaks a promise to go easy on him, accidentally biffing him on the chin. Martin graciously allows that your correspondent could indeed be a contender, though suggests he comes down a few weight divisions before turning professional.

The boxing ring, which hosts regular “fight-club” nights for emasculated city and media types, is—says Ollie Vigors, a co-founder of the Third Space—one of the ways in which the gym tries to differentiate itself, and keep its visitors entertained. Mr Vigors includes bowling alleys and bars, as well as other gyms, among his competitors. Other features designed to give the Third Space the edge include an altitude-controlled running chamber; a reduced-chlorine swimming pool in which members can learn to scuba dive; a climbing wall; and the opportunity to be serenaded by DJs or (on Sunday mornings) a gospel choir while you work out. There is also on-site alternative therapy, including “neuro-linguistic programming” and other offerings from the outer reaches of medicine and the English language.

Research suggests that twenty-somethings are more dissatisfied with their bodies than anybody else, although they tend to be in the best condition

Many American gyms, especially those in New York, have devised even more unlikely and exotic novelties to dispel the danger of somnolence. In New York's gyms, experimental exercisers can work-out by pretending to be fire fighters; participate in a “striptease aerobics” class (not an activity likely to appeal to beginners); or engage in the oxymoronic “bootcamp yoga”. Rick Caro, who founded the IHRSA and now runs Management Vision Inc, a specialist American consultancy, says that as the fitness business becomes more competitive—and with mini-gyms opening in, among other places, airports and shopping malls—more and more facilities are carving out specialist niches for themselves. Mr Caro believes that group workouts are one of the best ways to counteract boredom (partly because wavering participants can see that some other people are in a worse shape than they are).

So what, this sweating scribbler continues to ask himself, are the compensations of a pastime whose physical benefits are variable, and which is so dull that all manner of improbable hybrids and gimmicks have to be invented to keep people at it? Why do hordes of already-fit people devote so much of their time to such a boring and self-punitive pursuit? Most other forms of entertainment that have evolved with mass affluence—such as, say, the rise of foreign holidays—are more obviously enjoyable. Indeed, one standard critique of Anglo-American capitalism argues that, at a certain point, the puritanism that originally sustained it evaporated, to be replaced by a callow and self-indulgent hedonism; whereupon pleasure replaced graft as capitalism's ultimate good. What explains this masochistic anomaly?

Help thou my unbelief

Perhaps the answer lies in the access gyms offer to gaggles of lithe and scantily clad (if not entirely gumnos) strangers. Many gyms are indeed designed with plenty of glass and mirrors to facilitate mutual admiration. As Tris Reid-Smith—editor of the Pink Paper, a gay British weekly—says, there are some gyms that attract large numbers of “muscle Marys” or “gym bunnies”, as stereotypically muscle-bound gay men are known among their peers.

In some of these, gratification is not always exactly delayed. But the etiquette in most gyms, and the strict concentration on personal salvation that prevails, precludes much in the way of flirtation. Most of the admiration is of the narcissistic variety (it is the men, fitness instructors report, who are especially besotted by the mirrors).

Changes in the structure of relationships outside the gym may be part of the explanation: the increased likelihood of divorce and separation may have persuaded attached people, unconsciously or otherwise, that they ought to stay in shape, just in case. Along with the growing demand for male-grooming products, gym attendance among men may also reflect the growing power of women in the singles market: more and more men are now afflicted by the same sort of bodily anxieties that women have endured for decades. (A contrary explanation is that the emasculation wrought by women's gains at work and home has driven some men to fall back on muscular notions of masculinity.) Perhaps, for both sexes, muscles have come to signify prosperity, just as a suntan used to be the mark of an agricultural labourer but now denotes wealth.

Explanations based on the potential rewards of swelling biceps and flat tummies assume that, at some level, gym-going is motivated by the rational pursuit of happiness. According to a more pessimistic view, going to the gym is not pleasurable (however indirectly) but pathological. Oliver James, a clinical psychologist, thinks that the fitness cult is part of a wider pattern of self-flagellation, induced by the drawing of comparisons with inappropriate role models. More and more people feel inadequate, he believes, because the standards by which they judge themselves are the visions of perfection purveyed by seemingly benign television programmes such as “Friends”. Meanwhile, too many people fail to derive any solace from comparisons that are flattering to themselves, such as with the fat man in the changing room.

The result is an “horrendous perfectionism” which, Mr James believes, prevents people from enjoying the fruits of their affluence. Few will take this “horrendous perfectionism” to the same extreme as did Yukio Mishima, a celebrated Japanese novelist who, after building a splendidly buff torso from years of pumping iron, committed hara-kiri rather than grow old and ugly. But still, Mr James speculates that for every person who goes to the gym for a legitimate health reason, many more are engaging in low-grade attacks on their bodies, which, in most cases, are already absolutely fine. An extreme form of this can be found among bodybuilders, some of whom suffer from a pathological belief that they are puny. According to researchers in Melbourne, “muscle dysmorphia” (or “bigorexia”), as the delusion is known, often leads sufferers to exercise obsessively and gobble steroids.

There is some evidence to support the view that working out, and other forms of body-anxiety, may be sicknesses of affluence—driven by unreasonable and unachievable expectations about where the rowing machine can take you. One personal trainer confides that, whenever a client successfully hardens or tightens one targeted part of the body, he or she invariably moves on to the improvement of another part. Research suggests that twenty-somethings are more dissatisfied with their bodies than anybody else, when, in fact, they tend to be in the best condition. Anxieties about body-shape, epidemiologists in Canada have found, are most prevalent in affluent areas. On this analysis, going to the gym will only make things worse, condemning users to an endless and destructive cycle of perfectionism.

A slightly less depressing possibility is that the appeal of the gym cult lies in the structure of religion itself. Perhaps hedonism is losing its lustre, and rich westerners once again crave the shape and strictures, however masochistic, that orthodox religion once supplied. Like Christian salvation, the holy grails of gym-goers may be distant and unattainable, and the paths towards them painful, but the rules and routines that their pursuit involves seem to provide comfort to a new and growing breed of secular puritans.

In the end, gym-attendance, like most popular religions, probably has something to do with fear of death and the quest for immortality—as if a well-toned body could somehow stave off the day of judgment. Which, unfortunately, is just another way in which it is liable to lead to disappointment. Gyms may not actually be bad for most people who go to them; but, as a wise man once inquired about hard work, why take the risk?