F.I.T.T. Principle

Total daily energy expenditure depends largely on the type, intensity, duration of physical activity.

By altering each category, you could optimize your weight control, physical conditioning, lean body building, or even rehabilitation.  The F.I.T.T.

Principle is an easy guide to do just this, no matter what you choose to pursue for exercise.

Volume approach to training can be defined as taking how often you workout, how many sets, repetitions you do, how long it takes you, and combining it all together for the ultimate result.

Let’s take a look at how we can get that perfect total volume of the right exercise.


F.I.T.T. Principle:

Frequency: How many times per week you exercise, this is usually counted in days.


Intensity: How hard you exercise. Refer to the Borg Scale (previous post) for this one. Anything dark green or above is considered moderate intensity or higher, and therefore, aerobic.


Time: Also could be Duration of exercise. This is usually measured in minutes of exercise daily.


Type: Also could be Mode of exercise. This could be a sport, activity, weight/cardio/sport-specific skill training, or any type of conditioning workout.


Example: Krista resistance trains all her large muscle groups Tuesday, Wednesday, and Thursday for 35 minutes at 68% RM (Repetition Maximum).

F: 3 days a week

I: 68% RM, Moderate Intensity

T: 35 minutes

T: Weight Training



When incorporating walking or running into your routine, make sure to increase Frequency first, Time second, Intensity third, and Type last. This is to ensure that you start low- impact with a new activity, build up the time you try it before you build up the intensity, and lastly increase to a higher impact activity only once you’ve mastered the low impact activity at that base requirement level.

e.g. building up walking to the allotted 150 mins a week, most days of the week (CDC guidelines) at a moderate pace, before switching to jogging or running.


Feel free to reach out to  Krista Borsari, EP at Princeton Longevity Center at SheltonEP@theplc.net

And remember, here at Princeton Longevity Center, we are here to help you REACH YOUR POTENTIAL!