Mechanics first, then
Consistency, then and only then
intensity |inˈtensitē| noun (pl. intensities)
1 the quality of being intense
• an instance or degree of this
2 chiefly: Physics the measurable amount of a property, such as force, brightness, or a magnetic field
Intensity is where we make our money. You cannot have positive change without pushing the boundaries: we live at the margins of our ability. However, given the previous pieces in this series, we don't want to rush to intensity without a solid foundation of mechanics and consistency.
Let's assume you've put in the work to safely ratchet up the intensity. Intensity is power generated and work done. We can increase the power generated and work done by changing the variables of the workout via time, load, repetitions etc, but we want to do it smartly.
Throwing together a smörgåsbord of wildly large loads and a huge number of reps is stupid.
Simple is always best and CrossFit is most often prescribed in couplets and triplets. Occasionally we'll throw in a large rep workout, like Angie (100 pull-ups, 100 push-ups, 100 sit-ups and 100 squats) but we'll always always give people the opportunity and direction to scale it down if appropriate (like doing the push-ups on your knees). There's intrinsic value in keeping workouts short and hard. The longer the workout, the less power you can generate (F*d)/t