The acronym F.I.T.T. stands for Frequency, Intensity, Time, and Type in exercise prescription. It serves as a framework to structure fitness programs effectively. Frequency refers to how often exercises are performed, Intensity indicates the effort level during workouts, Time describes the duration of each session, and Type outlines the kind of exercise (aerobic, strength, flexibility). By adjusting these components, individuals can tailor their fitness regimens to meet specific health and fitness goals.