GEORGE BERNARD SHAW'S marathon "Man and Superman" is the Olympics of drama. At nearly four hours of words and little else, Shaw's grueling talkfest is an intellectual obstacle course -- for actor and audience -- but one that holds rewards for those with the endurance.

Shaw's story is simple -- ruthless Woman out to catch her Man, who fancies himself above such mortal weaknesses as romance. But oh, what glorious lengths Shaw goes to in telling it! In his sustained debate on the relationship between the sexes, Shaw makes room for healthy dollops of his progressive political views, among them the idea that the artist/superman has a responsibility to forsake earthly pleasure for higher aims.

The Man in question, Jack Tanner, is one of Shaw's sturdiest characters: an anti- romantic infatuated with his own turn-of-the- century modernity, a verbal swordsman who may be a descendant of the legendary Don Juan. But in the end, Shaw seems to contradict his own creation by allowing Tanner to succumb to the "marriage trap" engineered by shrewd Ann Whitefield, a woman with a penchant for impossible quests -- and ambitious men.

Here, the mature Shaw blows enormous, luminous verbal bubbles, then delights in having one of his characters pop them, only to begin another one.

Shaw has built an almost operatic structure: There are long verbal "arias" and Shaw returns all the characters and themes for an ensemble finale.

For this production, Arena has restored the "Don Juan" scene, a massive metaphysical dream in which Tanner becomes his notorious ancestor. The act gives the evening its intellectual weight, but for all Arena's showbiz trickery -- a lavish vision of Hell as a genteel dinner party -- the static sequence is fairly suffocating stuff, better suited to the printed essay. The final act, tellingly set in an enchanting garden, is business as usual, and in it bloom some of Shaw's brightest bon mots.

The fine cast, directed by Douglas C. Wager, sails through the dense verbiage, and gold medals for stamina and variety go to Francois de la Giroday as the elegant Tanner. Richard Bauer is a charmingly sentimental Mendoza/Satan, and Harriet Harris is coolly coquettish as Ann Whitefield.

Designed by Adrianne Lobel, with handsome costumes by Marjorie Slaiman, Arena's setting is typically good-looking. But Shaw's talking heads lend themselves better to the proscenium stage. At any given time in Arena's configuration, several characters will have their backs to the audience, resulting in the loss of or damage to some of Shaw's pearls.

But even with the losses, this difficult "Superman" is worth the superhuman effort of all concerned. MAN AND SUPERMAN -- At Arena Stage through February 17.