It is well established that exercise bolsters the structure and function of the brain. Multiple animal and human studies have shown that a few months of moderate exercise can create new neurons, lift mood and hone memory and thinking. But few studies have gone on to examine what happens next.
In a recent study, the brains of the animals that had been inactive for three weeks contained far fewer newborn neurons than the brains of the animals that had rested for only one week. The brains of the animals that had been inactive for six weeks had fewer still. In other words, you need to be consistent to obtain the mental health benefits of physical exercise. The same is the case for brain fitness.