Unless you were born on another planet, I'm sure you know that you need to eat your fruits and vegetables.  However we all find ways to ignore that advice. "I don't have time." "It's too much trouble." Scientists and nutritionists continue to find that most diseases can either be helped or prevented just by this dietary practice.  There is no substitute for eating a wide variety of fresh, raw fruits and vegetables, at least 7-13 servings every day. However, if you're like most people (myself included), you don't eat enough.  Even if you do, you probably only eat what you like, and therefore you don't get enough variety.   Also, most fruits/veggies tend to be overprocessed, over-cooked, or too far removed from the field, and thus lack much of the nutrition provided by fresh, raw fruits and vegetables. 

In addition to all of this, people who exercise need even more antioxidants than those who don't, because unfortunately excess free radical production is a byproduct of exercise.  The antidote to free radicals is to consume more antioxidants, especially from fruits and vegetables.