Mice who exercised grew more brain cells in a part of the brain associated with memory than mice that didn't exercise. Researchers say its a finding that may explain why physical activity can improve brain power.
The 105-day study included two groups of mice. One group was allowed unlimited access to an exercise wheel and ran an average of more than 20 km (12 miles) a day. The other group of mice weren't allowed to exercise, BBC News reported.
Tests showed that the mice in the exercise group were better able to distinguish between memories of similar things. This is likely due to the additional brain cells generated by exercise, the researchers said.
"Keeping similar memories distinct is an important part of having a good memory," said study senior author Timothy Bussey of Cambridge University, BBC News reported. "It is this aspect of memory that is improved by exercise, our study shows. The human equivalent might be remembering which car parking space you have used on two different days in the previous week. It becomes difficult to distinguish memories when events are similar."