The FIIT Principle: The Secret Power of Exercise Prescription

Lily Pentlin

ACSM Exercise Physiologist, ACE Health Coach

The F.I.T.T principle is a guideline for coming up with a well-rounded, efficient workout plan for both cardiovascular and strength training. Most fitness professionals will use this format to program their client’s individual exercise programs based on their ability level and goals.

Here is the breakdown of what the F.I.T.T principle stands for:

Frequency: The number of days per week are you engaging in that particular type of exercise. Cardio recommendations usually range from 3-7 days per week based on intensity, and strength recommendations can be anywhere from 2-6 days/week based on personal goals.

Intensity: How hard you are working. With cardio this could translate to heart rate, perceived exertion, speed, power, and a handful of other factors. With strength training we’re usually referring to total volume of weight lifted (reps x sets x resistance used). Intensity is something personal to each individual and their current level of fitness.

Time: How long are you spending doing that exercise. For cardio we focus on minutes or sometimes distance. For moderate cardio exercise the goal is generally 150min/week. For vigorous cardio the goal lowers to 75min/week. When we talk about strength training, we are referring to sets x reps with rest time factored in. For someone starting out even 1-2 sets of 10-12 reps can be effective.

But on this note, beginners might take longer to complete their workouts due to unfamiliarity with the movements, whereas someone more advanced could complete the same workout in a shorter period. However, a trainer might choose to program a shorter work out for someone brand new and a longer workout for someone that is more advanced.

Type: This refers to what exactly you are doing in the workout. Cardio examples include indoor/outdoor walking, running, cycling, swimming, elliptical or a handful of other modalities. For strength training this could be using bands, dumbbells, machines, bodyweight, kettlebells or any other form of resistance. Trainers will program this based on availability to the client as well as preference and current fitness status.

Now here’s the secret…you can progress or regress any fitness program by changing just one of these principles. Here’s an example: Say you feel like you are needing to kick it up a notch, but you can’t commit to any more days or time – try working with a greater intensity. Grab a heavier pair of weights or add some speed to your cardio. You will see progress without needing to extend frequency or duration. A regression example might be somehow who is just starting out and feels like they need to take it slower can decrease the number of days they exercise from 4 to 2-3. This decrease in frequency allows for more rest/recovery time while the body adjusts.

Each of my Fitness programs are created with a specific F.I.T.T principle in mind. If you are new to exercise, I highly suggest starting with my 4-week Fitness Jumpstart. It’s a great way to learn the fundamentals of strength training and cardio with my help and guidance the entire time!

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