University of Wyoming researchers studying the effect of drugs and hormones on athletes have discovered evidence that steroids can contribute to heart disease.

The evidence arose during tests on rats, while other tests on steroid levels in an athlete's blood system showed that some steroid levels decrease while others rise during exercise.John Wilkinson, director of the university's Human Energy Research Laboratory, said members of the university ski team are being tested during their peak training period to determine the normal blood level and production of the steroid hormones testosterone and cortisol.

Data from these tests helps the athletes recognize when they are overtraining, he said.

The research so far indicates that while fatigue is common in athletes who overdo their workouts, during these periods blood testosterone levels generally decrease or remain constant while cortisol levels tend to rise. When cortisol increases, muscle breakdown occurs.

Baseline information on the skiers already has been taken. Skiers were checked before and after the heavy training period during November and December, and a follow-up test will be administered just before the NCAA ski championships in Jackson next week.

One recently completed experiment involving rats showed that steroid use can lead to coronary heart disease. In this study, blood samples from the rats showed steroid use increases the levels of triglycerides, total cholesterol and lipoprotein cholesterol.

"This was particularly true of corticosteroids," Wilkinson said. "In our experiments, the significant elevation of cholesterols suggest an increased risk for (heart disease)."