Stress urinary incontinence involves the involuntary loss of urine due to physical activity such as coughing, laughing, or sneezing. It involves a weakening of muscular support at the ureterovesical junction, which causes hypermobility of the urethra during times of increased intraabdominal pressure. When you sneeze, cough, laugh or lift heavy you may have a urine leak. Sometimes while exercise or running you may have a urine leak.