How ever the question may appear , I will try to keep my answer as simple as possible. When you visit a gym and workout on your biceps ...the better you work out, the better your biceps looks day by day. Similarly when you eat healthy diet ,keep up your physical fitness , maintain a healthy lifestyle and good sleep ...the more you do it persistently.... the more your body and mind get fit. Your brain and mental fitness are a consequence of your state of mind and many more . Hence work on the above principles consistently