- Contact sports: Football and boxing (from suffering injury to the kidneys/bladder)
- Noncontact sports: Long-distance running, spinning, swimming
- March hemoglobinuria – resulting from trauma to red cells as you move your feet
- Rhabdomyolysis (Breakdown of muscle fibers) – leaking myoglobin into urine; Myoglobin is a protein in muscles. With exercise, your muscles use up oxygen. Myoglobin has oxygen attached to it, which gives the muscle more oxygen to maintain activity. When muscle is damaged, myoglobin is released into the blood and then removed in the urine. In some cases, over-exerting your muscles while weight-lifting can injur muscles.
In all of these cases, the red-brown urine gets better with rest, and isn’t a concern. If one week of rest doesn’t show resolution of urine symptoms, further testing is needed.