Exercise is the one of the many causes of hematuria (increased red blood cells excretion in the urine) (figure 1). Exercise-induced hematuria can be defined as gross or microscopic hematuria that occurs after strenuous exercise and resolves with rest in individuals with no apparent underlying kidney or urinary tract pathology .
Issues related to exercise-induced hematuria in otherwise healthy individuals will be reviewed here. Exercise may also worsen hematuria in patients with underlying glomerular disease, such as IgA nephropathy [2,3].
The general evaluation of adults or children with hematuria is discussed separately. (See "Etiology and evaluation of hematuria in adults" and "Evaluation of microscopic hematuria in children" and "Evaluation of gross hematuria in children".)
ETIOLOGY AND PATHOGENESIS
Hematuria has been described after a variety of forms of exercise [1,4,5]. These include contact sports, such as football and boxing, and noncontact sports, such as long-distance (marathon or endurance) running [6-8], rowing, and swimming. Hematuria appears to be rare with cycling but has been described, even with stationary bike riding (eg, spinning) [9,10].
The frequency with which hematuria occurs with long-distance running was evaluated in a study of 45 male and female participants who competed in an ultra long-distance marathon . After the race, 11 (24 percent) had hematuria. The hematuria disappeared within seven days. A similar incidence (18 percent) was noted in a report of 50 marathon runners who did not have hematuria on prerace samples obtained daily for three days .