“Physical fitness is not only one of the most important keys to a healthy body, it is the basis of dynamic and creative intellectual activity. Intelligence and skill can only function at the peak of healthy and strong.”

What this quote means is you have to be healthy from the outside but from the inside also. It is important to be healthy and believe in yourself. If you are really healthy it could give you a boost to be smarter and skills when you are physically healthy. If you are sick and don't sleep well it can prevent you from being intelligent or happy. An example is if you are taking all your medicine when you're sick you could get better and have a better mood. You can do all your stuff with passion and encouragement. Another example is if you're trying to have energy at school you should sleep more to be more awake and pay attention to your teacher. This could help you in school and get better grades because you're being mentally healthy. Having a healthy body is one of the important keys to your life.