Periodization refers to the planning, in distinct (but overlapping) periods, of your competitive year.
The easiest example is the linear periodization model, in which blocks of time are set aside to develop the athlete from the general to the specific. GPP (General Physical Preparedness) refers to the all-around athleticism that we seek in CrossFit; SPP (Specific Physical Preparedness) refers more to the specific skill of the sport. GPP was heavily used in the offseason to prevent boredom, recover from injury, and balance out muscle dominance.
In a broad sense, linear periodization models tend to move from the 'slow lifts' to the faster ones; from longer workouts to shorter; from higher training volumes to lower, more intense loads.
In this model, GPP would typically be placed at the base of the pyramid. Of course, domination over broad time and modal domains is our goal; CrossFit IS a GPP program.
Since power, for instance, is dependent on strength, a strength phase must precede a power phase to have the greatest possible effect. The greatest measurement of fitness, Work (force x distance) can be improved through the improvement of force potential, and then extending that force over a greater distance (or, in our case, time) without a loss in the components of force (speed and power.)
Other forms of more complex periodization have become popular in the last few years. Called conjugate periodization by most, these plans include two or more elements of fitness at once, but rarely in equal amounts. The most popularized model is the Westside method, which features two max-strength days, and two speed days, for powerlifters. Originally used by Soviet sports scientists to improve the function of weightlifters, the Westside method blends GPP training into the week after speed or strength sessions. 'Speed' and 'GPP,' of course, are relative: to a powerlifter, work capacity means 10 minutes' worth of pulling sleds around a parking lot, while to CrossFitters, it means "Murph." 'Speed,' to a powerlifter, means the acceleration of a lighter load (35-50%) over the distance of a few feet; to an Olympic Lifter, it means the Snatch; to a sprinter, it means fast starts.
In the conjugate method, different elements of fitness ebb and flow as competition approaches. For instance, the athlete may still have 'strength' and 'speed' days, but the relative loads of each will change depending on the time left before competition. Lifts become more important; reps decrease. There's a tendency – a bias – toward the same lifts used in competition, with the associated supportive gear.
If you've ever had a 'strength bias' in CrossFit – or done CrossFit Football – you'll undoubtedly notice that some things become easier, while others become harder. When you're stronger, 'Fran' gets a bit easier, since the 95lbs thruster taxes you less. However, if you've gained weight, the pullups become harder, and your stamina may decrease.
The beauty of periodization lies in the overlap between phases. It's commonly accepted that maximal strength will last for about 9 weeks after a heavy lifting phase; that means it's slowly tapering, but at a slower rate than you can gain other traits, like stamina. When these overlapping factors all come together, we call it your 'peak': endurance is up; stamina is at its best; strength is still high. Overall, work capacity is maximized for a short period.
This year, we know the date of the Open (February 22.) We know, better, what to expect from the workouts (barbells, rings, and calisthenics take priority over running, for instance.) We'll be overlapping phases of training – biases – to create the most optimally-developed athletes possible.
Strength, then, forms the basis of our pyramid. We'll do a short strength phase, move to a power phase, and then expand work capacity from the greater speed and proficiency gained at the start of training camp. Resist the urge to 'read ahead' – to do extra METCON on top of the strength work – and maximize the gains possible during each stage. Enjoy the process, in other words. You are the fittest people in town; let's pull even further ahead.