The presence of free haemoglobin in the urine associated with prolonged walking or running. March haemoglobinuria may be due to the breakdown of muscle (see also myoglobinuria) in the legs or to mechanical trauma on the soles of the feet damaging red blood cells, which release their contents of haemoglobin into the blood stream. The occurrence of blood in the urine of swimmers and rowers shows that exertional haemolysis (the splitting open of red blood cells during intense activity) may occur without obvious impact against an external surface. No treatment is needed for mild haemolysis, but in runners the condition can be avoided by not running on hard surfaces and by wearing well-padded shoes.
Subjects: Sports and Exercise Medicine.