Exercise is done by us, so our body remains fit and healthy. This improves our brain power too, Similarly to keep our mind more active, we need to provide some exercise it too. This boosts our brain power to do a lot many things in a more effective way
Based on leading neurobiological research, we can keep our brain alive by introducing a regimen of mental cross-training―a series of deceptively simple exercises that help stimulate the production of natural growth factors called neurotrophins, which in turn grow brain cells and keep the brain younger and stronger. And nothing so easily stimulates the brain as breaking routines and using the five senses in new and unexpected ways. So if you’re right-handed, wake up tomorrow and brush your teeth with your left hand. Or close your eyes before you get in the car and insert the key into the ignition. Every time you open a new circuit in your brain, it’s like doing a round of mental sit-ups. Challenging yourself to do one new task a day is the way to do this.
This prevents our retention/memory from declining with age. Mental decline is not usually from loss of brain cells as much as it is from loss of communication between brain cells.
This occurs due to the decreasing number and complexity of dendrites, the branches on nerve cells.