Macrocycles are the longest of the cycles, usually ranging from a few months to a year. A macrocycle combines all the training phases to achieve your final goal.
For example, if you want to
swim in an open water race next summer, your macrocycles include technique and endurance work. As you get closer to an open water event, the last phases of a macrocycle focus on tunning up speed while dropping the distances.
Essentially, a macrocycle is your long-term plan. It puts every micro- and mesocycle into perspective and aligns them towards your final goal.
A proper macrocycle covers all the aspects of your success in the water, such as training, rest, and recovery.