Recently the research has been held among elderly people having some memory problems. There have been taken 85 Australian people of 50 and more, who were asked to two hours to weekly physical activity, mainly brisk walking for six months. And even after that they were urged to remain active. These people were supported by encouraging letters.
There were also 85 people who didn't do exercises. The research shows that the exercises group has more progress in brain function comparing with the control group.
So, it can be said that physical activity, especially brisk walking, lead to slight improvements in brain function for those who have memory problems. The authors of this study say that the exercises don't reduce the risk of dementia or Alzheimer's. Still, there are evident improvements.