Sometimes when I'm feeling bored at the gym, I like to wonder about some of the unreasonably attractive men and women working out around me. Are they scientists? Are they spelunkers? Are they spelunking scientists? And if so, what would they do if, while on an expedition, they suddenly found themselves trapped a mile underground with fanged, digitized creatures that had no problem treating them like kibble? Luckily, I can put some of my curiosity to rest, because I've just seen ''The Cave," which answers every question I've ever had about what might happen when a handful of hotties head deep inside the earth. For starters, the middle-aged and intelligent die early.

Sorry, Dr. Nicolai (Marcel Iures), but you seem several decades older and many times smarter than the team of young American cave explorers you've hired to help guide you through the mysterious subterranean labyrinth you've found in Eastern Europe. Plus your foreign accent isn't British -- so it was nice knowing you. But hey, somebody does get gobbled up before you (though I didn't catch his name). As for the ones who've survived up to this point, they seem to have lunged out of an energy drink commercial. If the movie's sets weren't dank and soggy, we would see the Gatorade they probably sweat while trying to make their way back to the surface.

''The Cave" is hard to get into, if for no other reason than, like ''Wrong Turn," ''House of Wax," the ''Anaconda" sequel, and others, it's ultimately just a rigorous personal training film made by people who don't seem to like movies or the people who go to them. With nary a shot lasting longer than five seconds, it's not edited so much as blended. When it's finally over, we're not left with a horror film. We're stuck holding a protein shake.

In the meantime, the cast is a who's who of who's thats. The man running the expedition, Jack, is played by Cole Hauser, the star of last fall's ''Paparazzi." Eddie Cibrian, of ESPN's gambling drama ''Tilt," plays his brother, Tyler. Piper Perabo, that lass whose career hasn't been the same since ''Coyote Ugly," plays the obligatory tomboy obligatorily named Charlie. Lena Headey plays the British scientist, over whom the brothers seem bound to fight but never do. Daniel Dae Kim and Rick Ravanello play two other guys, and -- because it's becoming a crime for Hollywood not to make one of these movies without him -- Morris Chestnut reprises his part from that more enjoyably absurd ''Anaconda" sequel.

Together, they don't act so much as burn carbs. At the first sign of trouble, everybody treats the slippery cave as a climbing wall and uses the monster-stocked lake as a chance to get in a swim. No one seems exactly afraid of these critters. They seem pumped. Of course, the monsters are scary only if you've never been to an ''Aliens" movie (Cibrian faced down much more frightening creatures when he was on ''Sunset Beach"). Nonetheless, we take our cues from our heroes in such pictures. But what do our actors give us to work with?

The acting here is the stuff you come to expect from a cabinet, or whoever the woman is playing the prosecutor on ''Law & Order." Hauser in particular seems on the verge of turning his cardboard technique, which includes a bold refusal to inflect, into an art. In fact, he appears to be so masculine that you're afraid he might go off like a testosterone bomb. When it seems one of the creatures has infected him, someone observes, ''He's not human." But come on, was he ever?

Having worked as second- and third-unit director on the "Matrix" trilogy and "Dark City," Bruce Hunt is no stranger to inspired and stylish productions. But whereas those films managed to inject new life into tired territory, "The Cave," his first effort as director, fails to generate anything resembling innovation.

A group of ace cave-divers are flown in to investigate an intricate maze system discovered beneath the ruins of an ancient Romanian abbey. Without much explanation the gung-ho team - and two scientists - are lowered uncomfortably deep into the earth. It doesn't take long to learn that they are not alone, and are soon being preyed upon by what look like cheap creature rejects from the "Alien" films, except these demonlike mutations can fly and use sonar to see in the dark.

What is left of the plot amounts to guessing who will be killed off next out of the token Asian and African-American guys, the girl in the skimpy outfit, the sexy female scientist with an English accent and the testosterone-pumped combative brothers. Not that it matters much - the characters are so colorless and underdeveloped that their deaths certainly won't be mourned.

As utterly formulaic as the film may be, the elements for an edge-of-the-seat crowd-pleaser are, in theory, all present: a closed-off environment ideal for creating no-one-can-hear-you-scream suspense; stimulating underwater and wall-climbing action; exotic settings, shot on location in Bucharest and the Yucatán; and bloodthirsty villains.

It's a shame, a travesty even, that the filmmakers seem to have forgotten that in order to keep viewers from contemplating the absurdity of what they are watching the action must move at a pace that doesn't allow for it. But not only is the film dreadfully dull: every time something potentially exciting does occur, the scenes are so muddled and chaotic that it is impossible to make out what is happening.

As the leader of the expedition, Cole Hauser attempts his best Vin Diesel impersonation but fails to deliver even at this rudimentary level. The rest of the actors turn in performances right out of the casting room, as if they were reading the lines from the appallingly bad script for the very first time, embarrassed to discover that it's all been done before. And will indeed be done again. Let's just hope it won't be in a "Cave" sequel, a possibility the film's ending distressingly leaves open.