Many people who stay physically fit also find it helps them feel and be sharper mentally. There may actually be a physiologic reason for this phenomenon called neurogenesis.
According to the NY Times, using rats, scientists found very different levels of neurogenesis, depending on how each animal had exercised. In other words, some types of exercise affected the brain in a positive way while others, actually had a less impressive effect.
Read about this fascinating study here
Which Type of Exercise Is Best for the Brain?
By Gretchen Reynolds February 17, 2016
Some forms of exercise may be much more effective than others at bulking up the brain, according to a remarkable new study in rats. For the first time, scientists compared head-to-head the neurological impacts of different types of exercise: running, weight training and high-intensity interval training. The surprising results suggest that going hard may not be the best option for long-term brain health.
As I have often written, exercise changes the structure and function of the brain. Studies in animals and people have shown that physical activity generally increases brain volume and can reduce the number and size of age-related holes in the brain”™s white and gray matter.
Read more here