New European research suggests that exercise may not only help to protect the brain against a stroke, but it could also help improve recovery after the event occurs.

In an animal study carried out in the laboratory of Prof. Siegrid Löwel at Georg-August-University, Germany, the lab's team of researchers looked at the effect of exercise on brains of mice and its ability to protect against and rehabilitate the brain after a stroke.

To do this the team used a standard test to assess the brain's 'plasticity' -- its ability to change the way it activates in response to an experience.

The test involves compromising the visual input of one eye for a couple of days, so the part of the brain that processes visual information is activated by the other, open eye.

The brain's ability to change eye dominance -- called ocular dominance plasticity -- is related to age. It is stronger in younger mice and completely absent in older mice that have been raised without any stimulation.

The results of the study showed that mice that had free-access to a running wheel were able to maintain ocular dominance plasticity even after suffering a stroke, compared to those that didn't run.

The results also confirmed existing research that exercise can have an anti-aging effects on the brain, with older mice that exercised retaining the ability to change eye dominance in comparison to those that didn't.

In addition, the team also found that exercise could be used for rehabilitation after suffering a stroke, with mice that had no previous access to a running wheel showing an equally positive recovery if they engaged in voluntary exercise after a stroke had occurred.

"Our study suggests that physical exercise can be used as a preventive, as well as a therapeutic approach to aid recovery after a cortical stroke," says Dr. Evgenia Kalogeraki, who conducted the research.

"We found that mice with free access to a running wheel throughout their life preserved a more juvenile brain into adulthood and were able to prevent the negative effects of a stroke."

The team believe that the results suggest that exercise could be a simple but effective method to protect and rehabilitate patients that are prone to, or have already suffered, a stroke, with the results promising enough to encourage senior author Löwel to take up exercising again.

"The fact that the brain can restore its youthfulness by starting physical exercise after a stroke has occurred suggests that it is never too late to benefit from exercise," says Löwel. "I've started cycling again -- what is good for the mice cannot be bad for me!"

The results can be found published online in the journal Frontiers in Aging Neuroscience.