I listened to a USAT webinar last night and given how most of us are pro's so time is of the essence, these are the key take-aways:
Quality over Quantity: an hour of intervals well above race pace is better than 4 hours of mediocrity
Its not about volume but about how well you recover: more time training won't make you better if you're exhausted and/or don;t take the time to get the gains from training, and that means rest days
Do your intense efforts early in the week and endurance later....if you do the opposite you're trying to do intensity when you're already tired
pre-load key weeks based on training goals and events: its helpful to know ahead of time that key blocks of training are on the horizon
have benchmark testing for all events whether 4x1 mile for running, 4x100 swimming, and a cycling time trial...there are many options but you need to test to see improvement
know your training zones for LT, wattage, etc
train above your race pace, substantially above for shorter efforts, marginally above for longer.