Periodization in training describes dividing the (annual) training into different periods. These periods are often called blocks or cycles. With the help of periodization, your athletic performance should peak at specific competitions or events.
The different cycles differ in their length (time) and content. Useally, there are three types of cycles: the macrocycle, mesocycle, and microcycle.
The macrocycle is seen as the basic framework and includes the complete (training) year. It is thus the longest of the three cycles and serves for long-term planning. Therefore, it offers a rough overview of competitions, season-highlights, intense training and recovery periods. At the same time the macrocycle does not have to be oriented on the usual year. Rather, it is important to stick to a long-term goal, such as an important competition in a year distance. Then you have a macrocycle of about 52 weeks, which can be filled with targeted training content and other (less important) events.
It is also possible to integrate several macrocycles in one year. However, it is important to know that a higher number of macrocycles does not necessarily increase the performance because the overall preparation and training time is shorter.
The mesocycle is significantly shorter than the macrocycle. Often chosen lengths are 21 or 28 days. The idea of the mesocycle is to achieve a pre-set goal. For example, you can train for specific abilities or skills such as endurance, sprint strength, or threshold power. A 21-day mesocycle is typically set up as 16 days of relatively intense training, followed by 5 days of recovery (or 23 days of training and 5 days of rest for a 28-day cycle).
The microcycle is the shortest training block. It might be the cycle most familiar to you as it typically lasts for about a week. In a mesocycle you train highly focused on a short-term goal. For example, you could have four relatively hard training sessions tied together to produce physiological and neurological adaptations. In addition, a similar number of recovery days follow to prevent fatigue and overtraining. In general, three to four microcycles are strung together to form a mesocycle.
To summarize, the following can be said:
The three cycles of periodization (macro-, meso-, and microcycle) build on each other and serve to reach peak performance just at the right time. While the macrocycle is the backbone of your year-to-year planning, you train more specific performance features (endurance, strength, threshold power,…) in multiple mesocycles. The mesocycles in turn are built by microcycles. These reflect your normal training week, so to speak. Here it is important to focus on short-term goals. Also, it is important that there is enough time for recovery in each cycle to prevent overtraining or injury.