FITT Principle: The 4 Building Blocks Of An Effective Workout Program

Although working with a personal trainer or sports and conditioning coach can be a great way to take the guesswork out of training and have a fitness professional prescribe the best workouts for your goals and needs, working one-on-one with a trainer or coach isn’t cheap.

If you’ve been running or working out for upwards of a year or more, you might find that you’re in a place where you want to make your own training plan or plan your own workouts.

Creating your own workout plan can certainly save you money, and it also puts the power in your hands to fully customize your exercise to your preferences. With that said, how do you go about programming a workout, let alone building a training plan?

Haphazardly choosing what you want to do on a whim is arguably the easiest way to approach an exercise routine but it’s likely not going to be effective at helping you achieve your fitness goals.

Instead, following a strategic approach, known as the FITT principle, can provide you with the building blocks of an effective workout program.

In this article, we will give the FITT principle definition, explain how the FITT principle of exercise programming works, and how to use the FITT principle to create a fitness routine.

In this guide, we will cover: 

  • What Is the FITT Principle?
  • Frequency
  • Intensity
  • Time 
  • Type
  • How to Use the FITT Principle for Workout Programming

Let’s dive in! 

A notebook with a workout plan using the FITT principle.

What Is the FITT Principle?

Unless you studied exercise science, sports coaching, or kinesiology in college, you might be entirely unfamiliar with the FITT principle, so let’s start with the basic FITT principle definition before we delve into the details and how-tos.

The FITT principle, often written simply as the FITT principle, is an acronym that refers to a method for exercise programming that helps create, describe, and structure any type of workout plan using four different criteria.

The FITT principle stands for Frequency, Intensity, Time, and Type.

  • Frequency: How often you exercise 
  • Intensity: How vigorous or intense the workout is
  • Time: How long the workout is
  • Type: The type of exercise you perform 

Each of the four factors of the FITT principle need to be considered in tandem when building a workout program. 

A group of people running.

#1: Frequency

The first FITT principle criteria to consider is frequency, or how often you will exercise in your workout plan. 

Determining the appropriate frequency for your workouts depends on different logistical, lifestyle, and specific workout factors, such as:

  • The type of workouts you’re doing (HIIT vs. steady-state cardio, total-body vs. body part splits for strength training, etc.)
  • Your fitness level (beginner vs. advanced athlete)
  • Your fitness goals or what you’re training for (weight loss, competition, building muscle, etc.)

It can be seen that there are numerous intersecting factors to consider when it comes to determining the ideal frequency for working out.

With that said, the exercise guidelines for general health set forth by the American College of Sports Medicine (ACSM) and the Centers of Disease Control and Prevention (CDC) can provide a starting place for figuring out how often to exercise per week for both cardio and strength training workouts.

A person rowing.

Cardio Workouts

In the context of this discussion of the FITT principle of exercise programming, cardio workouts can involve performing pretty much any exercise other than strength training workouts.

Examples of cardio workouts include running, swimming, walking, rowing, boxing, jump roping, cycling, roller blading, hiking, and the elliptical machine.

Depending on your goals and workout duration and intensity, most guidelines report that you should perform moderate-intensity cardio workouts five or more days per week or doing vigorous cardio workouts three days per week to reduce your risk of disease and improve your health. 

The type of exercise also plays a role in the ideal frequency. High-impact exercises like running and jumping rope should usually be performed fewer days per week than low-impact exercise (cycling, walking, swimming, etc.) if they are the only type of cardio workouts you do.

Of course, the more experienced you are with running or high-impact exercise, the less of an issue this is, but even advanced runners should take rest days to allow the body to recover. 

In general, the more aggressive or lofty your fitness goals, the more frequent your workouts should be each week. 

For example, if your primary goal is setting a PR, running an endurance race or triathlon, or preparing for a competition, you’ll probably want to work out more often each week than if you’re just trying to improve your health and reduce the risk of lifestyle diseases.

The guidelines for improving health can be seen as the baseline or minimums for exercise frequency, and more serious athletes can build upon these levels.

The more variety in your routine, the safer it is (lower risk of overuse injuries) to work out more frequently. 

For example, if you only run, you should plan to take at least one day off per week in most cases, in order to give your body a chance to rebuild, repair, and reap the benefits of your training without breaking down.

In contrast, if you run a few times per week, do yoga once or twice, lift weights a handful of times, and swim laps, you can probably work out more frequently (even potentially twice a day) should you want to.

Again, when it comes to the type of exercise you do, the impact level of the activity, and repetitiveness of the exercise motion itself, and the overall variety in your exercise routine influence the ideal workout frequency.

In a nutshell, when it comes to exercise frequency, more is better up to a point, but that point is crucial—your body needs some rest to prevent overtraining syndrome and overuse injuries.

A person holding a dumbbell.

Strength Training

Strength training can involve lifting weights, using resistance bands, kettlebells, or even just your own body weight.

ACSM recommends adults perform two to three total-body strength training workouts on non-consecutive days each week. 

You should have at least one to two days off strength training between sessions, though you can do cardio exercise or flexibility-focused workouts (yoga, barre, stretching, etc.) on these in-between days.

When it comes to figuring out the best frequency for strength training workouts, the primary factor to consider is the type or structure of your workouts.

Broadly speaking, there are two general ways to structure strength training workouts: total-body workouts or split routines.

As the name describes, total-body workouts are routines that include exercises that use all the major muscles of the body over the course of the workout, giving you a full-body workout. 

In other words, if you are doing a total-body workout, there will be exercises that target your arms, others that will work your chest or back, exercises that strengthen your abs and core, and exercises that primarily target your legs. 

It’s also common to have several full-body exercises, such as burpees, or compound movements that involve several major muscle groups. For example, a total-body workout might include exercises like a reverse lunge with an overhead press or a side lunge with a bicep curl.

A person doing a step-up with a weight plate.

Body part splits or split workout routines focus on just one or two particular body areas per workout. 

Typically, the body is partitioned into arms and chest in one workout, back and core in another, and then legs, though there’s plenty of variability, particularly within the pairing and splitting of arms, core, chest, and back.

If you are following a split workout routine, all, or nearly all, of the exercises for any given workout are focused on the particular body area. 

For example, on arm day, you wouldn’t have squats or lunges, unless potentially paired with an upper-body exercise. Similarly, on legs day, you won’t find pull-ups or push-ups on the lineup.

The exercise guidelines are to work every major muscle two to three days per week, so if you’re doing total-body workouts, you’ll hit all the major muscles each workout, so you’ll only need to do two to three workouts per week.

On the other hand, if you do body part split routines, you need to work out nearly every day because you will be cycling through different muscle groups, allowing several days of separation before re-working the same muscles.

If your goal is increasing strength, 2-3 total-body strength training workouts per week should suffice. On the other hand, if you want to build muscle mass, more frequent workouts (and often split routines) are recommended.

A person jumping rope.

#2: Intensity

Exercise intensity refers to your effort level or how hard you’re working when you work out.

Cardio Workouts

Exercise intensity can be gauged through different methods, such as heart rate (either taking your pulse manually or wearing a heart rate monitor), rate of perceived exertion (RPE), and the talk test.

Easy cardio workouts might be in the 50-65% of your maximum heart rate range. 

Moderate-intensity cardio is usually done between 60-75% of your maximum heart rate. 

High-intensity intervals or vigorous cardio can be at or above 75% of your maximum heart rate, though there can be overlap of these ranges depending on the source.

It’s a good idea to do cardio workouts with some time of low-, medium-, and high-intensity work each week to work each metabolic system.

Strength Training

Exercise intensity for strength training generally depends on the loads you’re lifting, the types of exercises you’re doing, the rest intervals, and the power or speed that you’re exerting.

The main factor for workout intensity is the overall workload, which is determined by multiplying the loads you use with the number of reps and sets you do.

The difficulty of the loads you lift—how hard it is for you—is reflected by the relative percentage of one-repetition maximum (1RM). 

For example, if the most you can squat is 200 pounds, doing 100-pound squats is 50% of your 1RM and much easier for you than doing 150-pound squats, which is 75% of your 1RM.

Intense strength training workouts may have higher loads, more sets, more challenging exercises (compound movements, plyometrics, etc.).

Beginners should use lighter weights or lighter relative loads for more reps and sets to build strength and endurance.

If you want to increase strength or size (hypertrophy), you’ll need to work at a higher intensity, using heavier weights for fewer reps, but doing more sets.

A person on a treadmill with headphones on.

#3: Time

Time refers to the length of your workouts. How long you should work out depends on your fitness goals, the intensity of the workout, how often you exercise, and the type of exercise you do.

As can be seen by this list, each of the four constituent components of the FITT principle greatly affect one another.

Cardio Workouts

Most cardio workouts are 30-60 minutes, but there’s plenty of variation on either end.

HITT workouts or beginner workouts may be just 15-20 minutes.

Long workouts for endurance athletes such as distance runners and triathletes may be upwards of 2-3 hours or more.

The more intense your workouts, the shorter they tend to be and the more frequently you’re working out in a week, the shorter your workouts can be while still reaching the exercise guidelines for health.

Strength Training

The length of strength training workouts depends on whether you’re doing total-body workouts or split routines, the number of exercises you do, the number of sets and reps, and how long you’re resting between exercises.

Most total body strength training workouts take 30 to 60 minutes, and split routines may take 20 to 45 minutes or so.

A person running up bleachers.

#4: Type

The last component of the FITT principle for workout design is the type of exercise you perform.

Cardio Workouts

There are tons of different modes of exercise you can use for cardio workouts, such as walking, cycling, running, rowing, swimming, climbing stairs, elliptical trainer, jumping rope, cross country skiing, and hiking.

The more variety you do, the lower your risk of overuse injuries and the more well-rounded you will be in terms of muscular strength and endurance.

Strength Training 

There are also different modalities for strength training workouts, particularly when it comes to considering the type of resistance you use.

You might use dumbbells, barbells, kettlebells, medicine balls, resistance bands, bodyweight, sandbags, etc. 

All of these different implements will provide a somewhat different stimulus to your body.

A person biking on the beach.

How to Use the FITT Principle for Workout Programming

Using the FITT principle gives you a manipulable framework for how to design a workout program targeted towards your fitness goals.

You can visualize each of the four factors—frequency, intensity, time, and type—as different controllers on a sound engineer’s mixing board. 

You can play around with dialing one up and another down until you find just the right mix for your goals and needs.

Variety is not only the “spice of life” but also the key to preventing boredom, fitness plateaus, and overuse injuries, so make sure you’re modifying at least one or two factors from one workout to the next.

For some quick, intense exercise, check out our HIIT running workouts!

A clipboard with a workout plan on it, a whistle, dumbbells, water bottle jumprope and sneakers.
Photo of author
Amber Sayer is a Fitness, Nutrition, and Wellness Writer and Editor, and contributes to several fitness, health, and running websites and publications. She holds two Masters Degrees—one in Exercise Science and one in Prosthetics and Orthotics. As a Certified Personal Trainer and running coach for 12 years, Amber enjoys staying active and helping others do so as well. In her free time, she likes running, cycling, cooking, and tackling any type of puzzle.

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