To win in sport you need to be at your physical peak. You have to drag every ounce of talent from your body to compete against others who will be striving to do the very same. Every one per cent extra you can add to your performance levels will matter.
And thats where your diet comes in. Get this wrong and your whole regime will fall apart. You need the right diet in order to get the most from your workouts and sporting activity. The wrong diet will hold you back and undermine your performance in the gym and on the field.