Correction

The article, "A running laboratory: Marathon to test more than speed," in the Oct. 25 issue of Medical Center Report incorrectly described aspects of a study of marathon participants. Runners were to be tested three times: the day before the Oct. 29 race, immediately after the finish and one day later. If abnormalities were found, repeat tests would be performed a week after the race. This is the first study to do such a follow-up. Participants also received an echocardiogram prior to the race, not after.