This is the type of stuff that REALLY gets me jazzed up. I can read the timeless works of Aristotle and see that what I preach is old news. As you read this, think of how it relates to fitness. Especially the questions that everyone always ask me, "How much protein do I need?" "How many calories?" "How often do you work out?" "Should I do cardio fast or slow?" Blah, blah, blah.
Aristotle says what I always say. Do what is right for YOU, and only YOU know what YOU need.
In another passage in Nichomachean Ethics, Book II, he is more concise when he says:
Too much or too little gymnastic exercise is fatal to strength. Similarly, too much or too little meat and drink is fatal to health, whereas a suitable amount produces, increases, and sustains it.
I couldn't have said it better myself.