Hi Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concern. Blood in urine can be due to many reasons. 1.Most common is Urinary tract infection. Urine examination would be done. Presence of Pus cells , tissue and red blood cell will suggest infection. Antibiotics will be needed. 2. Stones in the kidney, bladder or ureter may cause bleeding if small stone gets passed through urinary tract. 3.Trauma by vigorous exercise can also cause bleeding in urine. This possibility is also more in you as you told that you have been exercising this summer. 4.In males prostrate hyperplasia can also cause difficulty in urination & blood in urine. 5.Other uncommon kidney and Urinary tract problem including tumor. So you should visit your urologist, if problem persist or reoccurs Don t worry you would be fine Hoping your query is solved.