The Method
ABCD
Four training days, four letters.
ABCD is the training division for four or more days a week, and the one the app suggests: four Program Days, A, B, C and D, repeated across your week.
In the default week, A is Push Day, B is Pull Day, C gives the shoulders their own day with the abs, and D is Legs Day. Other weeks lay the four days out differently, with two lower-body days. The letter is the organization: your Program shows what each day trains.