An athelete came to casuality with 3 days history of passing red colour urine.most propable cause of red colour urine in this condition is-

Both hemoglobin and myoglobin give red colour to urine. Here the patient is athelete, due to strenous activity , myoglobin may be excreted in urine ,which is giving red colour to urine . Ref:physiology and pathology of urine by john dixon ,pg no. 49