We tend to think that exercising is good for health but has nothing to do with brain. But, the research on the article seems to deny the mindset.
When it comes to maintain cognitive ability, we try to stimulate brain by dealing with information like studying or memorizing. I guess it's not the bad approaching but not sufficient one. As well as informational way, we should protect brain by physical way. In other words, it is to keep a good circulation by exercising.
For me, it is surprising news, because I've never devoted to sports activities in the long term. I should make it a rule to exercise on a weekly basis.