'Runner's Trots'

Abstract

Derek Clayton, describing aftermath of his world record marathon run (Runner's World, May 1979, p 72). WITH the recent popularity of running, physicians should recognize various "abnormalities" that occur in healthy runners, either as physiological adaptations to physical training or as normal responses to extreme exertion. These include various bradyarrhythmias, left ventricular enlargement, proteinuria, and hematuria. The bradyarrhythmias, such as sinus bradycardia, Wenckebach or junctional rhythms, or first-degree atrioventricular block, are due to high parasympathetic tone in the athlete.^1,2Left ventricular enlargement is thought to be a physiological adaptation to endurance training and does not represent a pathological disorder.³Proteinuria, which may be due to relative renal ischemia, is gone 48 hours after exercise.⁴Hematuria in runners may be due to superficial bladder trauma in most cases.⁵ Conspicuously absent from the medical literature is the description of gastrointestinal (GI) symptoms experienced by many runners. These GI