Trainer Bill Donovan was admitted to Johns Hopkins Hospital last week, but it is safe to say he doesn't regret the excesses that brought him there.

Donovan was suffering from exhaustion brought on by the hectic pace and stress of training his colt Lost Code, who has won six straight races and who might be the best 3-year-old in America.

"I've been pushing hard since February," Donovan said, "flying around the country from track to track. I caught a virus at the Ohio Derby but I wouldn't stop and it got into my lungs. Finally, I couldn't even put one foot in front of another."

If doctors counsel him to avoid stress, Donovan could answer that during his first 30 years in the business he avoided the stress of training a top class horse. He has waited a lifetime for the chance to worry about a horse like Lost Code. And this opportunity could never have meant more to him than it does now, for Lost Code came along at one of the lowest ebbs of Donovan's career -- when he had been virtually driven out of Maryland after spending more than a decade here.

Donovan had scuffled around minor tracks for many years when he and his wife Donna decided, in the early 1970s, that they should settle somewhere. They chose Maryland, and though Donovan enjoyed no spectacular success -- in some years he won only a dozen races -- he was content here.

He was, at least, until the spring of 1986. Donovan never liked the way Pimlico's track was souped up before the Preakness; several of his horses had broken down on the hard surface. When he expressed this opinion to Pimlico general manager Chick Lang, the two exchanged heated words. Donovan said Lang told him no other trainer ever had made that complaint; Donovan said he called Lang a liar. The next day racing secretary Larry Abbundi called Donovan and told him he would no longer have stalls at Pimlico when the meeting was over. Donovan was exiled to Bowie -- Maryland racing's version of Siberia, except that Siberia may be more picturesque. Donovan and his wife started making plans to leave Maryland permanently.

It was during this exile at Bowie, however, that Donovan developed the colt who would drastically alter his life. He had bought Lost Code for owner Donald Levinson of Baltimore earlier in the year and, the trainer said, "I loved him from the day we got him; he was big, strapping, good-looking. And I knew he was a good one when he ran the first time at Laurel. But I never dreamed he'd be this good; I was just hoping he would be able to run in a few little stakes."

Donovan left Maryland during the winter and took his stable to the inaugural meeting of the Birmingham Turf Club, and it was there that Lost Code started to make a national reputation. The 3-year-old son of Preakness winner Codex won a small stakes and followed it with a decisive victory in the $350,000 Alabama Derby. Ordinarily, that might have prompted a trainer to start thinking about the Kentucky Derby. But Donovan had not dreamed that Lost Code might be this good and had not nominated him for the Triple Crown.

This oversight might have been a blessing. Donovan didn't have to face the temptation of running Lost Code in these tough races; instead, he was forced to take a path of lesser resistance.

From Alabama, Donovan took Lost Code to Sportsman's Park and won the Illinois Derby. Next he won the Ohio Derby at Thistledown. Then he led all the way to win the St. Paul Derby at Canterbury Downs. Even though these races may not offer the glory of the Triple Crown, they offer plenty of money: Lost Code has earned $811,076 this year. Moreover, by running in easier spots, he has stayed fresher than other colts who have gone through the wringer of the 3-year-old classics. At Canterbury, he finished 14 lengths ahead of a tired Cryptoclearance, who contested the whole Triple Crown series.

Lost Code should find another relatively easy spot Saturday, the $150,000 American Classic at Arlington Park. If he wins there, Donovan plans to give him his shot at the big boys at last; Lost Code would go to Monmouth Park on Aug. 1 to race against Alysheba and Bet Twice, the horses who dominated the Triple Crown races.

With such a prospect ahead, what doctor is going to make Bill Donovan rest and relax? The trainer expects to be in Chicago for his horse's next start, and to be worrying about him for the reason of the season. There will be plenty of time for rest when this once-in-a-lifetime fantasy is over.