Saturday night in Dublin's Liberty Hall and the air smells of deep heat and tanning oil. A couple of hundred eager faces await the first competitor in the IABO `Natural' Body-Building Championships and straight away you start to wonder. Is this sport? Back-stage they're furiously warming up on the bench press and flexing in giant mirrors before taking to the floor. Just one look at these guys and it's hard to imagine how Michelangelo could have carved out better features, but there is a certain amount of disbelief about it all.

The people from IABO (that is the Irish Amateur Body-Building Organisation), however, are quick to differentiate between the grotesque, vein-bursting sort of stuff that often pops up on satellite sports channels and has as much credibility as WWF wrestling. This is natural, drug-free competition and set to become a demonstration sport at the 2004 Olympics.

The three-man judging panel certainly watch earnestly as each competitor starts his routine with seven mandatory poses. They range from "back double biceps" to "front abdominal and thigh isolation" and the idea is to show off every working (and non-working) muscle for all its worth. Then comes the free posing routine - backed with music for added effect - and a comparison round, if necessary, to separate the leading two performers.

These championships were run in seven categories, starting with the Juniors and then the oddly titled First-timers, through to the final "posedown" which decided the overall trophy. Stephen Gavin was clearly ecstatic and equally deserving of the junior title, but it wasn't completely limited to male flaunting.

Midway through the three-hour event the Miss Figure/Fitness category brought out the women. Pound for pound they don't come much better than this, especially when eventual winner Niamh Colgan began her musical routine and made you wish you'd taken that seat in the front row.

There's no doubt the crowd enjoy what they see, especially the female contingent gathered at one corner of the stage. And like a heavyweight title fight, they often shout wildly at what could be a winning pose.

Without much competition, 32-year-old John Rafferty from Belfast took the Open category gold medal (which is actually more like a medallion). He was impressive, but on the whole not quite as much as Senior winner Eric Dowey who, at 63, seems to have discovered muscle immortality.

He started with Charles Atlas routines at 14, and went on to be Mr Britain and runner-up in the Natural Mr World. "I see the weights as my friend," he says. "But it's not an obsession. It's positive energy use and certainly a good way of getting kids off the street corner."

The final routine of the night sees all six winners (excluding Miss Figure) take on each other for the overall award. This is the most aggressive part as they battle for the judges' attention and it created something of a surprise in that Sean Connelly, who won the Novice title, claims the trophy.

To ensure the good, clean fun there will be random drug tests a few days after - right now the competitors are chronically dehydrated as part of the preparation - but that is more a deterrent then to seek out the guilty.

"These guys have zero to gain from taking any sort of chemicals," explains the IABO president, David Kelly. "You can tell from their size that it's not necessary. Four competitors here will be selected at random but that is more to discourage anything illegal."

That, it appears, is the big difference from the professional aspect of the sport and their idea that to conquer the world is not enough. Mr Universe would be way out of place here, so maybe there is a sane reason for all this after all. "Naturals" may not become the jogging for the new decade, but with gym culture taking on a whole new status, it can only attract a growing number of supporters.