The critics are in a muddle. Some are hailing Matthew Barney as the "strikingly intelligent" saviour of modern art - the "Damien Hirst of America". Others just point to his work and say pull the other one. And I'm with them, I'm afraid. He paints using vomit and fish blood, for goodness sake. It's a classic case of the emperor's new clothes.

Astonishingly Barney has been working on Drawing Restraint since 1987, when he first became interested in the idea of resistance training, or hypertrophy, as practised by athletes. Since then he has been trying to apply the same principles to his art. So he restrains himself while drawing by lifting dumbbells, or hanging off the side of a boat.

Imagine trying to draw a picture on a ceiling by jumping on a trampoline. Well, this is what Barney does. We're even shown a film of him doing it. Fun for him, tedious for us. And the result is just what you would expect - a series of scratches on a ceiling.

Barney is evidently more interested in experimenting with the creative process than the final outcome. Proof of this is the display case containing stacks of his framed drawings, only the top ones visible. I ask why we can't see them. "It's to create viewer restraint," I'm told. It's a strain not to laugh out loud.

As frivolous but more impressive are his sculptures. They're huge, weird and feature vast quantities of Vaseline, a material with which he's obsessed. Perhaps he is right to be - it's fascinating stuff, looking like mashed potatoes or lemon curd on a massive scale.

One piece is made using dead shrimp flesh. Get close and you can smell them. And the smell is getting stronger, say the poor staff at the Serpentine. If you want to see the show, go now before it becomes even more of a stinker.

Drawing Restraint. Serpentine Gallery (020 7402 6075). Barney's film, also called Drawing Restraint, is showing daily at the Gate Cinema, W11 (0870 755 0063). Both until 11 November.