When I first started in the fitness industry (in college) the Exercise Rx was F.I.T (Frequency, Intensity and Time). Then it was expanded to F.I.T.T the mnemonic for Frequency – Intensity – Time and Type. Today there’s an addition beyond FIIT which adds a VP. VP adds the concept of volume and progression. It forms the most basic concept in developing exercise prescriptions/programs and helps identify minimal thresholds for benefits. In this article, we’ll look at FITT-VP and what it means, plus how to use the information in your exercise program.
Even though the F.I.T.T-VP formula applies to all exercise prescriptions it will vary depending upon goals, medical status, culture, fitness level and more. Herein we’ll be mainly addressing general exercise guidelines in relation aerobic exercise and F.I.T.T-VP.
F – Frequency
Frequency relates to the number of days per week a person should engage in exercise (e.g., 3 days per week). It varies, but the general recommendation is 3 – 7 days per week. Depending on goals this may change. For example, persons who are interested in weight control would benefit from exercise on “most days”. In other words between 5 – 7 days. Whereas heart patients who are recovering from a recent heart attack may start with only three days during their rehabilitation program. In all cases, people who are just beginning an exercise program should build from the minimal to greater frequency.
The American College of Sports Medicine (ACSM) recommends a goal of moderate-intensity aerobic exercise at least 5 days per week OR vigorous intensity exercise 3 days a week OR a combination of both.
I – Intensity
Intensity refers to how hard you are working. There are a number of ways to monitor exercise intensity with the most common being exercise target heart rate (THR). THR refers to a heart rate range that is a percent of estimated or measured heart rate reserve (Max HR – resting HR) or maximal heart rate. Even though there are different ways to calculate THR and charts to help people identify it, it is just a starting point and may require adjustment after a person begins their program. Some disease states such as coronary artery disease and medications like beta-blockers will affect THR. Individuals with medical concerns should contact their healthcare provider to confirm what is best.
For some people rate of perceived exertion may be a good alternative or adjunct to THR. Using an RPE scale of 1-10 moderate intensity would be between 5-6, and vigorous 7-8). Another way of measuring exercise intensity is by oxygen consumption values such as METs or metabolic equivalents. Generally speaking 1 MET = a resting state. The higher the MET value for an activity the more intense. For example, working at 3-6 METs is considered moderate-intensity activity. Here are some examples of MET values and activities. Generally, more vigorous activity involves less time. Contact a fitness or medical professional to determine this.
But always use SENSE during your session meaning:
Start Exercise Nice and Slow… Everytime!
T – Time
Time is simply the period spent in an activity. Currently, the ACSM has recommended that people spend at least 150 minutes per week engaging in a moderate aerobic activity. In point of fact, there has been recent research that minutes per week spent in aerobic exercise is more important than frequency. In other words, 3 days of fifty minutes per session of vigorous aerobic exercise will yield the same benefits as 5 days of thirty minutes. Given this, if an individual is deconditioned they may break sessions down to 10 minute periods during the day and accumulate 20-40 minutes of aerobic work.
T – Type
Type refers to the modality of exercise one uses, such as walking, cycling, swimming or types of weight/resistance training. Picking a type is dependent on issues such as goals, readiness, ability, medical status, and interests to name a few.
Using F.I.T.T provides us with the framework to make decisions about managing the volume of exercise (frequency x intensity x time). It also helps develop a well-rounded program by using various types to impact different components of fitness. Finally, and probably most important, using F.I.T.T helps us encourage and increase the enjoyment of exercise. So let’s put the F.I.T.T in fitness to get great benefits.
V – Volume
The volume of exercise is determined by the frequency, intensity and time. This can be calculated by energy expenditure (MET·min) which is done by multiplying the MET value of an activity by the time spent performing it. For example, if a person performed aerobic activities at 6 METS for 150 minutes during a week the volume would be 900 MET·min·wk. The ACSM recommended MET·min target is between 500-1000 MET·min·wk. Pedometers can also be used to track volume with 5500 to 8000 steps per day meeting the minimal physical activity recommendations for most adults.
P – Progession
Progression can be viewed as happing in stages: Initial, improvement, and maintenance. The initial gains in aerobic fitness are seen in the first six to eight weeks of training. It is not unusual for the novice exerciser to see gains of 3% a week in the first month and 1-2% during the next 4-8 months. For the average person, 5-20% increases in aerobic fitness can be expected with deconditioned individuals experiencing up to 40% improvement. Athletes due to their high levels of aerobic conditioning see 2-5% gains.
During the initial phase of aerobic training, the average person should progress to sustain moderate activity for at least 30 minutes after starting at about 20 minutes per session 3 days per week. Remember to make SENSE during your program (see above). Once the above is achieved, during the improvement stage, intensity, duration, and frequency is increased but never at the same time. Duration and frequency should be increased to the ideal targets before intensity is increased. The rate of progression depends on many factors beyond the scope of this article. Seek help if you are unsure of how to progress. Usually, this progressive period can last between 4-8 months. After a person has achieved their cardiorespiratory fitness goal, maintenance begins.
Using F.I.T.T-VP provides us with the framework to make decisions about managing the volume of exercise (frequency x intensity x time). It also helps develop a well-rounded program by using various types to impact different components of fitness. Finally, and probably most important, using F.I.T.T-VP helps us increase the enjoyment of exercise as we can get benefits in a safe and planned process. So let’s put the F.I.T.T (VP) in fitness to get great benefits.