The acronym "F.I.T.T." stands for Frequency, Intensity, Time, and Type in exercise programming. This principle helps individuals structure their workouts effectively. Frequency refers to how often one trains, intensity indicates the effort level, time specifies the duration of the workout, and type refers to the kind of exercise performed. By adjusting these components, individuals can tailor their fitness programs according to specific goals, such as building strength or increasing endurance.