Healthy Living Blog

The FITT Principle

The FITT principle is a lesser-known phrase that is used to prescribe fitness and exercise recommendations to clients. This principle is taught to future personal trainers, exercise specialists, and exercise physiologists as a way to adjust a client’s workouts incrementally to achieve consistent progression without overloading the client in one area.


F – Frequency
Frequency refers to the number of days per week that you complete the given modality of exercise. For example, if you jogged on Monday, swam on Tuesday, and attended a spin class on Saturday, then your “frequency” for cardio is three days for this week. The same can be applied to strength training, but we usually use body parts to separate it out. For example, if you did squats on Monday, pushups on Tuesday, leg press on Thursday, and pullups on Friday, then you had a frequency of two days per week for both your upper and lower body for a total of four days of strength training.

I – Intensity
Intensity refers to difficulty. Cardio can use many different measurement tools, such as heart rate or 1-10 scales. Another example would be to use inclines on a treadmill or resistance on an elliptical as the intensity measurement. For strength training, the actual weight you’re using is the most common way of modifying intensity. However, you can still use heart rate and manipulating your rest periods between exercises to increase intensity.

T – Time
For cardio, time may be the most straightforward component to explain; it is the length of time you are exercising. If you jogged a mile and it took 15 minutes, then your “time” is 15 minutes. Strength training can fall under the same measurement, but I like to use “sets and reps” as the way to measure or increase your time. For example, if I lift 50 pounds for three sets of 10 reps, I can then increase either my sets or reps, and my “time” increases by doing so. The reason I like this more than just using the length of time I worked out is because we all have a different pace to our workouts. And for us to include our rest time between sets could get confusing. Also, for cardio, a longer time means the workout is harder, but for strength training, if I complete the same amount of weight, sets, and reps but in a longer time, that means the workout is actually easier.

T – Type
Type is described as what you are actually doing. For cardio, a type could be walking, swimming, biking, jogging, rowing, and so on. For strength training, your type could be free weights, Pilates, circuit classes, or anything else that falls under strength training.

Why use the FITT principle?

The benefits of using these four parameters can easily be understated. I like to focus on increasing a client’s “time” first, then “frequency,” then “intensity,” and lastly “type.” This approach is focused on the health, wellness, and longevity of the client and is overall most likely to see consistent progression. If you can handle two days a week on a treadmill at 5.5 mph for 30 minutes, then the easiest improvement would come from the “time” category. Increasing frequency could disrupt your weekly schedule too soon. Increasing intensity too soon could lead to more injuries or make you fatigued more quickly. Rather than creating a one-size-fits-all program, Structure House works with each participant to create a plan that works best for them. If you enjoy a certain form of exercise, Structure House can help adjust the frequency, intensity, and time as you progress to produce the best results.