At this point, it is a widely-known fact that maintaining a regular exercising regime has some effects on the brain, with the main ones being an improved memory and thinking capability.
As a matter of fact, scientists have actually demonstrated that exercising can stimulate the growth of new brain cells. However, until recently, it was widely unknown why exercising had such effects on the brain. Why until recently?
Well, a study was published not long ago in the Proceedings of the National Academy of Sciences, demonstrating that right after exercising, sex-related hormones shoot into the brain, something which heavily contributes to its transformation. While the study was only conducted on male rats, the researchers are positive it applies to females as well, not to mention, humans.
Why did they choose only males? Well, it was already a known fact that estrogen (the primary female sex hormone) is produced in the brain and that it can have several beneficent effects on it, such as the growth of new brain cells… at least, that's what Burce S. McEwen claims, who is the Director of the Laboratory of Neuroendocrinology at the Rockefeller University of New York. Long story short, males were chosen because relatively little was known about testosterone and how it affects the brain.
Because the researchers still weren't sure that the testosterone was produced in the brain as well as the testicles, they castrated some of the rats while other ones underwent a placebo surgery and left untouched (in other words, they really went the extra mile on this experiment, ensuring all animals went through the same experience). Also, some of the rats were injected with inhibitors preventing male sex hormones from binding to the brain receptors, regardless of whether or not the animal actually produced them.
Exercise Promotes Testosterone Production in the Male Brain Independently of Testes Function
The next two weeks involved some of the rats jogging regularly on treadmills while the others simply loafed around, taking care of whatever business rats have. At the end of those weeks, they found that the rats that had been exercising had significantly more DHT (dihydrotestosterone) in their brains, which is a very strong and potent derivative of testosterone. The interesting part is that the rats who were castrated and exercising also had high levels of DHT in their brains. In conclusion, they managed to prove that exercising can indeed promote testosterone production in the brain.
Exercise May Increase Cognitive Ability in Men
In addition to that though, it was found that the rats who exercised had an increased number of brain cells in the hippocampus, the part of the brain responsible for anything having to do with memory and learning. The rats whose brain receptors were tinkered with to prevent male sex hormones from binding to them did not receive any benefits, regardless of whether or not they exercised. In conclusion, Dr. McEwen stated that DHT is necessary to "achieving adult hippocampal neurogenesis" (neurogenesis is the creation of new brain cells).
Is Exercise Good for Women's Brain, too?
While this may be very good news for the men out there, this begs for the question: do women get any of these benefits? Well Dr. McEwen believes that to be likely, due to earlier experiments which contrasted the state of neurogenesis between the brains of old male and female rats; while the males were sedentary, female rats remained active, and they had a much higher rate of neurogenesis in their brains.
Women May Get Even More Benefits…
It is very possible for estrogen to be playing a role similar to testosterone when it becomes a question of exercising, not to mention that females produce both of those hormones. As a matter of fact, Dr. McEwen theorizes that there are some still unknown benefits to the interaction between male and female sex hormones in the brain, meaning women may get even more benefits out of exercising than men. As of now though, there is still a distinct lack of tests (…and testes… just kidding) and studies being done when it comes to the effects of sex hormones on the brain, so it will take a bit of time to see the real picture.
To finish this off, it should pointed out that there is one somewhat soothing point about the experiment, and it's that the exercising to which the animals were subjected was quite mild, meaning that only a bit of regular exercising is enough to tremendously improve one's brain functions, consequently reducing the chances of developing brain-related diseases and conditions.
To sum it up in a nutshell, most people are capable of doing light exercises from time to time, and it will go a long way towards helping them lead a fulfilling life.