WHEN Graham Roxburgh had a medical to mark the passing of his 60th birthday a couple of years ago, the doctor suggested that with so much research going on into sickness, it would be a splendid idea to research what makes us healthy, writes Marian Pallister. The doctor's inspiration stood before him: a man in what the French call so kindly the troisieme age who runs, sails, and hillwalks like a man in his prime.

What makes Roxburgh so hale and hearty when many other men of his generation have slowed to a standstill? How does the sixtysomething outstrip many a thirtysomething in the fitness stakes? How many men (or women) 20 years his

junior could undertake the gruelling Scottish Islands Peaks Race, on which Roxburgh embarks this Friday?

This event starts out from Oban, each craft carrying three sailing crew and two runners. After a six-mile cross-country run at Oban, the boats sail up the Sound of Mull to Salen, where the runners are rowed ashore to run 20 miles, taking in the 3400 peak of Ben Mhor. Then the boats sail through the night to Jura from Mull, where the runners do another 20 miles over the three Paps of Jura. The sail continues round the Mull of Kintyre to Arran, where there's a run up the 3200ft Goat Fell, before heading for the finishing line at Troon early on Monday morning.

The trip is some 160 nautical miles, and there are 60 miles of running. Last year, one of Roxburgh's runners had an injury, and he, as substitute runner, covered the Goat Fell part of the race.

He is on the substitutes' bench again this year, but confesses he would rather stick to the sailing. He says of last year's run up Goat Fell: ''I survived, but I am over 60.''

Co-runner Stevie Bell took Roxburgh's pack of provisions, but we are still talking about running up

a mountain.

What is Roxburgh's secret? He has been running since the age of 15 and says mildly: ''I have been keeping reasonably fit for years.'' A consulting engineer who was heavily involved in the Art Lover's House designed by Rennie Mackintosh (and, incidentally, has also restored Craigie Hall, his own Mackintosh-designed property on the south side of Glasgow) he says he is lucky to have an office situated handily for running up and down the mound in the middle of Bellahouston Park six to eight times, as well as getting

away to run up ''the odd

hill''. Over the holiday weekend, for instance, he ran up one at Loch Melfort on the Argyll coast in the middle of a sailing break.

He says his diet is healthy, he doesn't smoke, but drinks in moderation, the odd half bottle of wine and a few pints of beer. His profession is demanding, but with Bellahouston on his doorstep, he uses the dry ski slope in winter, the jogging trails, and the fitness centre.

Successful though he is, he does not choose to exercise in an exclusive fitness club, leaving the rest of us without the excuse that we have neither the time nor the facilities to get in trim.

This weekend, Roxburgh, his son Angus, experienced crewman Angus Horne, and fell runners Bell and Ronnie McCulloch will not only set out to achieve a good time in the event (and to have some fun along the way, he says), but will be raising funds through sponsorship for the Dochas Fund.

Roxburgh read in The Herald that John Paterson was suffering from Guillain Barre Syndrome and Motor Neurone Disease and was raising funds for research into both diseases by creating cards from his paintings. Roxburgh's father suffered from Guillain Barre Syndrome some years ago and he had nursed him through it, but more than that, he recognised a kindred spirit in Paterson: a man who loved art, a runner, a sailor.

On a trip to Crinan, he visited him, offered to raise funds for the Dochas charity the family has set up (dochas means hope in Gaelic), and now he is contacting friends, colleagues, and business associates for sponsorship for the event.

Roxburgh says: ''We do what many people do, we race for a cause. Last year we raised #1400 for a cancer charity, but when I recognised I share John's enthusiasms, I decided to race for the Dochas Fund.''

Maybe next year, it will be for that fund to research what helps a man like Roxburgh stay healthy.

n If you would like to sponsor Graham Roxburgh, telephone Margie Littlewood on 0141 427 6884 for a sponsorship form, or send cheques for the Dochas Fund to Craigie Hall, 61 Rowan Road, Glasgow G41 5BS.