Principles, considerations, and components of an exercise prescription

The principles of an exercise prescription refer to an exercise program involving frequency, intensity, time and type. This is also known as FITT. Frequency is the number of times per week or per month the exercise program is taking place. The intensity refers to how hard the workout or load is (Liguori et al., 2021). For example, intensity will refer to the percentage of an individual's 1RM, which can be written out as 70-80% 1RM. Time is how long each session is. Finally, the type is also referred to as the mode, and refers to the equipment or modality being used. Prescriptions should also consider exercise volume, which is the total amount of exercise over a session or a week's time. They should also include progression, which stands for exercise advancement that occurs throughout the exercise program. Progression can happen by adding more intensity, time, frequency or volume (Liguori et al., 2021). Applying these principles will be different for every person and population, based on their age, current health status, physical fitness level and personal preference.

Furthermore, there are also special considerations for every exercise prescription. Exercise is typically safe, if performed properly. However, the exercise professional (EP) is responsible for preparing a pre-exercise evaluation before the actual prescription, to avoid any risk of cardiovascular disease or musculoskeletal complications. After the pre-exercise evaluation, it’s essential to begin with light-to-moderate intensity and progress in volume and intensity over time. An individual's exercise prescription will also consider their personal life, and examine any barriers in their current lifestyle. To encourage exercise longevity, the EP must make the plan realistic to match the person's lifestyle; consider the occupation, social environment, schedule flexibility, etc. Behavioral barriers may also play a factor in beginning or continuing to exercise. Some individuals need to understand the importance of exercise and how it can improve several health and musculoskeletal components that come with aging (Liguori et al., 2021).

Finally, once the EP is ready to formulate the exercise training plan, they must consider each component. For each session, there must be a warm up, conditioning phase and cool down. All of these components will be discussed in detail below.

FITT for aerobic training & special considerations

The recommendation for improving cardiorespiratory fitness (CRF) is 150 minutes a week of moderate intensity, 75 minutes of vigorous intensity, or a combination of the two. However, when you have a highly trained individual, 300 minutes of moderate intensity and/or 150 minutes of vigorous intensity may need to be considered to impact improvement on CRF. The frequency recommendation is typically 3-5 days/week. The EP must consider what type of schedule works for the person and what is realistic. Exercising more days a week at a shorter time has not proven to be more beneficial, than exercising for fewer days at a longer period of time.  Hence, depending on the client's availability, the EP could organize a combination of times, leading to a desired frequency. For intensity, it is encouraged to begin with light-to-moderate intensity and progress over time. The baseline intensity will depend on the person's age, current fitness level, medical background, and results from their aerobic capacity assessment, if given one. The EP must consider the overload principle, in order to seek physiologic changes in the body. Every person or group of people responds differently to certain V02max ranges. For example, in someone who is sedentary, a V02 max of 70-80% could result in a sufficient stimulus and make a significant impact. While a highly trained individual may not benefit from this intensity as much. Therefore, the EP will need to enhance their efforts to reach a V02 max of 80-100% on a highly trained individual (Liguori et al., 2021).  In order to accomplish this, there are different variations of aerobic intensity. Interval training has proven to make the same physiologic adaptations that endurance training does. Using different forms of interval training, such as sprint interval training (SIT) and high intensity interval training (HIIT) is great for many populations, but especially for those who have limited time. HIIT and SIT induce a V02max of 80-100%. This intensity can also be reached through resistance type exercises as well (Liguori et al., 2021). Hottenrott et al. (2012) analyzed 34 recreational endurance runners and split them into two groups. The first group did two sessions a week, involving 2 hours and 30 minutes of endurance running, while the second group did four 30-minute sessions of high intensity training, along with a 30-minute endurance run, weekly. The intervention was 12-weeks and all participants ran a half marathon at the end. Both groups showed improvements in V02 Peak and visceral fat. However, the high intensity group showed a larger improvement in V02 Peak, concluding that this potentially is the better option for improving aerobic fitness in runners (Hottenrott et al., 2012).  In order to find an individual's Vo2 max, there are several formulas that exist. A very common one that is 220-age has become an unreliable formula, but is still being used in some facilities (Liguori et al., 2021). However, a study from Shookster et al. (2020) analyzed different age-predicted-max-heart-rate equations to an actual Vo2max test done on a treadmill. Although they found that all equations tested poorly related to the actual heart rate max, the FOX equation (220-age) was the best for predicting heart rate in a diverse population (Shookster et al., 2020).

The time or duration of the session must also be considered, depending on the client's availability and other behavioral factors. The general population is recommended to do 30-60 minutes of moderate intensity or 20-60 minutes of vigorous activity each day. Many people just starting out an exercise regimen may feel discouraged, insecure or unmotivated. It’s important to let them know that even 10 minutes can make a difference in their physical activity level and overall health (Liguori et al., 2021). Lastly, type or mode may be the most important aspect of the exercise program when looking at the behavioral and emotional side of fitness. Many people will hate running or cycling, and believe that they hate cardio and will feel discouraged to begin any aerobic activity. It’s essential for the EP to provide a variety of aerobic activities and find a mode that works for that client. For example, the person may prefer boxing or swimming as a form of aerobic exercise.

Finally, developing goals and targets for the volume and progression of the exercise program will help to not only advance the individual, but also motivate them and improve the longevity of the program. As mentioned before, 150 minutes of moderate intensity or 75 minutes of vigorous intensity every week is recommended to gain substantial health benefits. However, adding up the number of METs is a great way of estimating weekly volume. 500-1000 METs a week has shown to correlate with predicting lower rates of cardiovascular disease and mortality. When discussing progression, this will continue to increase as the person becomes more physically fit. Increasing each session by 5-10 minutes every 1-2 weeks for the first 4-6 weeks can help safely progress the individual (Liguori et al., 2021). 

FITT for resistance training & special considerations

Resistance training is a combination of strength, hypertrophy, power and local muscular endurance. After the EP has done the pre-exercise evaluation and gained the current fitness level, they can make a proper exercise prescription. If the EP is training an untrained individual, performing only one set of 8-12 repetitions, once a week, for every muscle group can promote neural adaptations, leading to physical results much faster than a trained individual. When training an individual who is past the novice stage, the EP should prioritize training volume over frequency, as this is the main component for improving muscular fitness. Next, intensity will vary based on the person's current fitness level, background and desired goal. Also, if their goal is either power, endurance, strength, or hypertrophy. However, 8-12 repetitions is typically recommended for general muscular fitness goals. For muscular power, 1-3 sets at loads of 30-60% 1RM for the upper body and 0-30% for lower body are recommended. Repetitions can vary from 6-20. Power training decreases at a much faster rate than the other components of muscular fitness. Hence, power training can be very beneficial for the older population. Power training can aid in improving balance, proprioception and preventing potential falls (Liguori et al., 2021). What's more, for the elderly population, power training can also combine loads of 20-80% 1RM on stationary machines, such as the leg press and chest press. Developing power, along with balance and flexibility can enhance this population, allowing the EP to add in more plyometric and speed, agility and quickness drills, as well (Green et al., 2022). When training for hypertrophy, the load can vary, as long as the individual works to repetition failure. Local muscular endurance is usually combined with lighter loads of 15-25 repetitions. Although, applying heavier loads can still enhance muscular endurance, when including short rest periods in workouts, such as circuit training or high intensity functional training (Liguori et al., 2021). Endurance training increases cardiovascular and musculoskeletal adaptations, which enhance exercise capacity and performance. These adaptations can delay muscle fatigue and expand aerobic capacity (Hughes et al., 2018). Hence, when training a long distance runner or swimmer, endurance resistance training should make up a large part of the exercise prescription. Finally, intensity levels for strength can range from 40-85% based on the individual. Typically, anything greater than 60% 1RM is recommended. If you have someone whose goal is maximal strength, increasing loads to greater than 80% 1RM is recommended (Liguori et al., 2021). A study from Thomsen et al. (2022) examined patients with Myasthenia Gravis, putting them through several tests including a maximal strength test. Therapies involving maximal strength exercises showed improvement in muscle weakness, especially in shoulder strength. After a follow up, they also examined that there were larger improvements in patients who began therapy when recently diagnosed (Thomsen et al., 2022). Finally, when looking at the mode or type of exercise, population must be considered, but personal preference is essential for the EP to understand, in order to promote longevity of the exercise program. The mode can be broken down into multi joint movements, single joint movements and core exercises. Performing a combination of all of these can help promote muscular fitness and includes a variety to keep the workout enjoyable. It’s important to train opposing muscle groups (agonists and antagonists), in order to avoid muscular imbalances. Hence, if the client is performing chest presses working the pectoralis, they should also include a lat (latissimus dorsi) pulldown, or dumbbell pullover. Finally, when analyzing volume and progression, these two components are essential in improving muscular fitness and vary greatly based on the individual (Liguori et al., 2021).  Liguori et al. (2021) provides the example of a person performing a chest press at 100 lbs for 10 repetitions until fatigue. This individual could increase the load by 5% at the next training session. This can also be done by increasing the number of sets or frequency per muscle group each week (Liguori et al., 2021). 

Flexibility

Flexibility and joint range-of-motion (ROM) is essential for avoiding muscular imbalances and potential injury. This can be especially important in the elderly population, as mobility starts to decrease. Static stretching is a popular way of stretching, but must be done properly to avoid deleterious effects on the body. Static stretching can decrease neural inhibition and muscle stiffness, but can also hinder certain performances, such as maximal strength and sprinting when done for more than 60 seconds at a time. Dynamic stretching is another popular mode used in warm ups for many populations, including athletes. This type of stretching raises core temperature and increases neuromuscular conduction, resulting in increased energy production. Flexibility exercises are recommended 2-3 days a week. Depending on the person and goals in mind, the intensity and mode will vary. Typically, holding a static stretch for 10-30 seconds can increase ROM. For older populations, 30-60 seconds can enhance flexibility in a shorter amount of time (Liguori et al., 2022). 

Components and exercise prescription

Considering all of the information above, the EP must develop an exercise prescription involving a warm-up, conditioning, and cool-down phase for each exercise session. Frequency, intensity, time, type, volume and progression will be included in the prescription. Each exercise session should begin with a warm up, or initiation phase. This will properly prepare the body for the movements occurring in the conditioning phase. A successful warm up increases the heart rate and blood flow, mobilizes the joints being used, while improving their ROM and elevates the joint fluid viscosity (Haff & Triplett, 2021; Liguori et al., 2021). Warmup program designs will vary based on the population and the goal in mind for the exercise session. The EP should plan on what muscles are going to be used, and plan a proper warmup accordingly. A dynamic warm up incorporates larger muscle groups to enhance cardiorespiratory endurance, resistance exercises and aerobic exercises (Liguori et al., 2021). For sport specific athletes, the warm up should include specific muscle/joint groups with the sport in mind. The conditioning phase will include resistance and aerobic training, as well as flexibility. As mentioned before, depending on the population, resistance training will vary based on the goals. For the elderly population, once balance and strength goals are met, power training is a very effective method that helps improve their proprioception and neuromuscular efficiency. However, for an endurance runner, working on muscular endurance may be more beneficial to enhance aerobic capacity. Overall, 150 minutes of moderate aerobic activity or 75 minutes of vigorous activity is recommended. For more advanced athletes, 300 minutes of moderate aerobic activity or 150 minutes of vigorous activity should be included. This will come down to the individual's background, current fitness level and personal preference. Finally, the cool down phase will help bring the individual back down to baseline levels (Liguori et al., 2021). Van Hooren & Peake (2018) suggest that a cool-down should be different for each individual. They state that the cool-down could potentially influence the effectiveness of the recovery and the preceding workout. Cool downs should include low-to-moderate-intensity exercise to increase blood flow rather than cause additional fatigue. A cool down can last up to 30 minutes depending on the conditioning phase (Van Hooren & Peake, 2018). Also, this phase should help bring the individual to a more relaxed physiologic state (Liguori et al., 2021).

References

Gordon, D., Wightman, S., Basevitch, I., Johnstone, J., Espejo-Sanchez, C., Beckford, C., Boal, M., Scruton, A., Ferrandino, M., & Merzbach, V. (2017). Physiological and training characteristics of recreational marathon runners. Open access journal of sports medicine, 8, 231–241. https://doi.org/10.2147/OAJSM.S141657

Green, Bryan J. CSCS; Mang, Zachary Ph.D.; Ducharme, Jeremy Ph.D.(c); Kravitz, Len Ph.D., CSCS. Benefits of power training for the elderly population. ACSM's Health & Fitness Journal 26(6):p 12-17, 11/12 2022. | DOI: 10.1249/FIT.0000000000000816

Haff, G., & Triplett, N. T. (2021). Essentials of strength training and conditioning. Human Kinetics. 

Hottenrott, K., Ludyga, S., & Schulze, S. (2012). Effects of high intensity training and continuous endurance training on aerobic capacity and body composition in recreationally active runners. Journal of sports science & medicine, 11(3), 483–488.

Hughes, D. C., Ellefsen, S., & Baar, K. (2018). Adaptations to endurance and strength training. Cold Spring Harbor perspectives in medicine, 8(6), a029769. https://doi.org/10.1101/cshperspect.a029769

Liguori, G., Feito, Y., Fountaine, C., Roy, B., & American College of Sports Medicine. (2022). ACSM’s guidelines for exercise testing and prescription (11th ed.). Wolters Kluwer.

Van Hooren, B., & Peake, J. M. (2018). Do we need a cool-down after exercise? A narrative review of the psychophysiological effects and the effects on performance, injuries and the long-term adaptive response. Sports medicine (Auckland, N.Z.), 48(7), 1575–1595. https://doi.org/10.1007/s40279-018-0916-2