Intensity in the FITT model relates to the amount of exertion that should be invested in a workout. According to the American Academy of Pediatrics, the FITT model reflects what should be in a fitness plan. For a moderate intensity workout, a few vigorous activities are added throughout the week.
According to Dr. Christina Hibbert, the FITT principle encompasses the fundamentals of exercise, the crucial elements for exercise programs that work. The acronym FITT stands for frequency, intensity, time and type of workout, emphasizing the importance of achieving a balance between conditioning the body without overstretching it. Dr. Hibbert suggests that heart rate and the RPE scale, or rate of perceived exertion, are two ways of measuring the intensity.