The document discusses the F.I.T.T. principle for exercise - Frequency, Intensity, Time, and Type. It provides guidelines for each element: Frequency recommends exercising cardio 5 times a week at moderate intensity or 3 times a week at high intensity, and strength training 2-3 times a week. Intensity can be measured on a 1-10 scale or by heart rate zones. Type means choosing appropriate exercises. Time depends on fitness level but a general guideline is provided. The document provides an example family fitness plan and criteria for assessing plans.