The report also shows that most asthma deaths occur with organized sports rather than with recreational sports.

Still, the researchers emphasize that the benefits of physical activity for patients with asthma are well established and far outweigh the very small risk of death.

The results stem from a study of 61 asthma deaths that occurred in close association with a sporting event. Dr. Jack M. Becker, from Drexel University in Philadelphia, and colleagues identified these cases by searching a nationwide clipping service for sports-related asthma deaths that occurred between 1993 and 2000.

Basketball accounted for the most fatalities -- 13 (21 percent), followed by track and gym class with 7 and 6 deaths, respectively. Most deaths occurred in the fall, followed by the summer, spring, and winter. The new findings are reported in the Journal of Allergy and Clinical Immunology.

Thirty-five of the deaths (57 percent) were attributable to an organized sport, whereas 26 (43 percent) occurred with a recreational sport, the researchers note. Of the organized sport deaths, about half occurred during participation in the sport, usually at practice rather than in a game.

Forty-two of the deaths (69 percent) involved males and the predominant age group was 10 to 14 years. White subjects outnumbered black subjects almost 2 to 1.

Fifty-five of the cases (91 percent) involved a patient with a known asthma history, but most were not using long-term control medications.

"The object of this study was to raise the awareness of physicians, coaches, trainers, and parents that children and adults can have fatal asthma exacerbations during and immediately after participating in sports," the researchers note.

Nonetheless, "the positive benefits to an active lifestyle have been clearly documented in asthma and other chronic diseases and cannot be negated by the risks outlined here," they emphasize.

SOURCE: Journal of Allergy and Clinical Immunology, February 2004.