Apparently you really can have too much of a good thing, even exercise.

Although an active lifestyle that includes exercise is viewed as a key part to managing high blood pressure and heart disease, new research finds that excessive exercise worsens high blood pressure and speeds up heart failure in rats, according to a Reuters report detailed on Scientific American online.

Dr. Rebecca L. Schultz and colleagues at the University of South Dakota, Sioux Falls, report the results in the journal Hypertension.

Click here to read the whole Reuters story

The implications for humans are not yet certain, according to Hypertension editorialists Dr. Paul Christian Schulze, of Boston University Medical Center, and Satyam Sarma, of Brown University Medical Center in Providence, Rhode Island. However, the findings "should raise our awareness" of the potential harm intense exercise might do to people with untreated high blood pressure.