So, I hit the gym tonight and got a shock. After about 20 minutes of cardio I pissed blood. No blood before I started, and none I can see now (a few hours later). I even went ahead with my leg training for an hour, right after this happened. I've asked Dr. Google, and it seems some runners get random blood showing up in their urine. Anyone out there have this issue before? Was it the strain of exercise, and was there anything that helped? I've emailed my doctor and plan to visit if she she says she thinks I need too, or if the blood shows up again soon.