THERE'S REPUTED to be a statistic that shows that while novelists live to 90, playwrights only hack it out to 60. Maybe it's all the post-show drink. Or else the rehearsal-room fags. That and the low esteem.

Whatever the cause, the writer of American Bagpipes, Clyde Nouveau, and The Sex Comedies has decided he wants to stick around. His New Year resolution was to cut out the artificial stimulants. No alcohol, no cigarettes. He's tried it before, of course, but never has he felt so little temptation to go back. Three months into his regime he says the worst point is when he's working out, and a lack of adrenaline leaves him momentarily exhausted. Other than that, he is a wholly healthy Heggie.

Which should quell his fears that the play that made his name, A Wholly Healthy Glasgow, might have lost some of its topicality in the decade since it was first produced. Iain Heggie's debut comedy, which won the special prize in the inaugural Mobil playwriting competition and was produced at the Manchester Royal Exchange in 1987, is set in a down-market health club where the libidinous staff are thrown by the arrival of an employee who is genuinely concerned with fitness.

The playwright's own new-improved, clean-living lifestyle, and the shelves of trendy fitness magazines in the newsagents, suggest that today we are even more obsessed with matters corporal than we were 10 years ago. That's not to say Liz Carruthers's new production of A Wholly Healthy Glasgow will provoke the same angry Daily Record and Sunday Post headlines about it doing down the good name of the city (must have been a slow news week), but it does bode well for a play that, shamingly, has never been seen on home turf.

The Royal Exchange took it to the Edinburgh Festival of 1987, where it was acclaimed as the funniest show in town. It was produced on television in an expletive-deleted version at about the same time. Only now is it being treated to a Scottish production .

So how does the former Glasgow health-club trainer feel about seeing his life as a playwright so neatly measured out in one 10-year chunk? ''It's quite mind-blowing,'' says Heggie, 44, over a mineral water (ice, no lemon). ''I find it shocking that it's 10 years ago. The period has been divided up by experiences. Certain things in my personal life - geography and relationships - have made boundaries round it. A Wholly Healthy Glasgow was written before very specific events in my life which are now at an end, and it's like all that period is in brackets, and I'm back to where I was before.''

To be performed by the purpose-built Dressing Room Theatre Company (the name was conjured up a matter of hours before an Arts Council application deadline; don't be surprised if you never hear it again), A Wholly Healthy Glasgow has been lightly trimmed by the playwright, with a couple of scenes more substantially re-arranged. So will it be a better play this time round? ''Who knows?'' says Heggie. ''The old saw is that it's best to be as short as possible, so in that sense I would say so. But you never know about things like contemporaneousness. It's hard to measure where the world is now. I think people change much less than people would have us believe. People who are in nineties dress, doing nineties things, fundamentally remind me of their parents. Nevertheless, fashions come and go, particularly in comedy. Comedy is iconoclastic, so it depends on the audience still getting joy from

that icon being knocked down. My conclusion is that jokes about health are still in.''

Never short of a spiky opinion on the state of the theatre industry, Heggie is as positive as I've ever seen him about his own writing career. He still says if the work dries up he'll switch to something else - and even now he sidelines as a tutor of acting and playwriting - but he's talking with renewed enthusiasm about a sitcom for Channel 4, and about two stage commissions, one from the Royal Exchange, the other from a Scottish theatre. He's keen, too, to let Scotland see his last play, An Experienced Woman Gives Advice, after plans to tour 1996's Royal Exchange production, starring Siobhan Redmond, were thwarted by an IRA bomb, forcing the company out of its central Manchester home.

One source of Heggie's reborn vigour is Lavochkin-5, the forthcoming Tron Theatre play by Alexei Shipenko, which he has translated from the original Russian with artistic director Irina Brown.

''I read the first three-quarters of Irina Brown's rough translation and I felt a measure of excitement about it,'' he says about Shipenko's controversial, scatological study of life for posh Muscovites in post-Soviet Russia. ''I thought if I'm going to do this once in my life for fun, I'd rather do it with this than a Moliere. We did the whole translation across the desk, going from Irina's rough translation, and me forcing her back to the original Russian, and to describing the deepest level of motivation. She was surprised how often what we ended up with was much more like the original Russian than her literal translation. She decided that we writers were in collusion!'' He continues. ''It's really got my appetite going. It's something to do with texture. I have been preoccupied with story, trying to get better at telling the story, which modern plays are not good at. Now, if I had time

to rewrite An Experienced Woman, it would be tightening up and improving the texture of it. It hasn't whetted my appetite for doing more translations, but it has for writing more plays.''

n A Wholly Healthy Glasgow is at The Arches, Glasgow, from Wednesday, and on tour; Lavochkin-5 is at The Tron, Glasgow, May 2-24.