Sources: danjohn.net and Chris Duffin's Youtube Channel
Dan John clarifies that a warm-up is more than switching on the radio. More than tuning in and turning up the volume, your warm-up can be used as a gauge to measure weakness and help with program design.
Use your warm-up to review and CONQUER your weak points!
Putting this mindset into action, in the video below Chris Duffin illustrates how his glute-activation warm-up dictates what exercises he'll be doing for the day and how heavy his working sets will climb.