Nested timescales of a plan
Periodized training is usually described at three nested scales. The macrocycle is the largest, often a full season or year, oriented around major goals or competitions. The mesocycle is a block of several weeks, commonly in the range of three to six, devoted to a particular emphasis such as building volume or developing strength. The microcycle is the smallest practical unit, typically a week, that arranges individual sessions.
Several microcycles make up a mesocycle, and several mesocycles make up a macrocycle, so the structure works like a calendar of decreasing zoom.
Why the layers help
Thinking in nested cycles lets a coach align day-to-day sessions with medium-term emphases and a long-term goal, and schedule recovery, progression, and peaking at the appropriate scale. It turns a vague year-long ambition into concrete weekly decisions.
Flexible boundaries
The exact durations are conventions, not fixed laws, and they vary by sport, competition calendar, and athlete. This is general educational information about planning structure, not medical advice.