Exercise prescriptions are an underutilized tool to improve community health. In moderate doses physical activity can help prevent and manage chronic health conditions that significantly affect the social and physical functioning of individuals worldwide scale.
Safe and effective exercise supplements require careful consideration of the target individual’s health status baseline fitness goals and preferences. Several national and international organizations provide guidelines for clinicians and allied health professionals on how to conduct screening tests and when appropriate, prescribe exercises for the benefit of their patients/clients.
Before beginning an exercise program the American College of Sports Medicine (ACSM) and the American Heart Association (AHA) recommend screening to identify cardiovascular risk factors. Studies help reduce the risk of negative responses to exercise as even moderate exercise can trigger cardiac events in mostly sedentary individuals.
With this in mind, two tools are recommended to facilitate the risk assessment process for physiotherapists. The most commonly used questionnaire is the PAR-Q followed by the Fitness Facility Pre-participation Screening Questionnaire.
- The PAR-Q is a brief 7-item questionnaire that uses a yes/no response format to identify personal risk factors.
- In contrast, the fitness facility pre-participation screening questionnaire was slightly longer and captured more detailed information on cardiovascular symptoms.
Screening results classify potential participants into 3 risk levels: low, medium and high.
- Low-risk population: Men younger than 45 years and women younger than 55 with no more than one cardiovascular risk factor. 
- Moderate Risk: Stratified for men over 45 and women over 55 with 2 or more risk factors.
- The highest risk category includes anyone with known cardiovascular pulmonary or metabolic disease or who exhibits signs or symptoms of cardiovascular disease.
Signs and symptoms that automatically lead to high-risk stratification include:
- Painful discomfort in the chest, neck, jaw, arms, or other areas that may be caused by ischemia.
- Shortness of breath at rest or with light exercise.
- Orthopnea or paroxysmal nocturnal dyspnea.
- Ankle oedema.
- Palpitations or tachycardia.
- Intermittent claudication.
- Unusual fatigue or shortness of breath during daily activities.
- Known heart murmur.
Based on this information, a decision on the need for a medical examination/counseling can be made before further testing. Below is a summary of medical clearance and testing recommendations based on an individual’s level of risk and the level of activity he or she wishes to perform Participation
Risk Profile Medical Clearance/Counseling Exercise Testing Conditions Low-risk individuals and vigorous exercise Submaximal or maximal testing not necessary; no physician to provide appropriate emergency procedures Moderate risk individuals and moderate exercise Submaximal or maximal testing not necessary; no Physician with emergency procedures in place Physician supervision recommended for moderate risk individuals and vigorous exercise Testing for maximal exercise recommended for high risk individuals and moderate to vigorous exercise Physician supervision recommended for submaximal or maximal exercise test
Assessment of Exercise Capacity
Various protocols exist for measuring baseline exercise capacity. Aerobic capacity exercise tests fall into two categories: maximal and submaximal tests.
- The maximal test is reserved for assessing the ability of individuals to participate in vigorous exercise.
- For individuals who only participate in moderate- or low-intensity exercise, submaximal testing is sufficient. Noonan & Dean collected information on submaximal test-specific protocols. 
Exercise prescription is based on 5 principles: Type Duration Frequency Intensity and Volume.
- Type refers to an approach to exercise training in which the main methods are aerobic (i.e. endurance training) resistance (i.e. strength training) flexibility and balance. Duration and frequency are used to describe the duration and amount of physical activity in a season. Intensity is defined as the amount of effort the participant is exerting and can be measured in a variety of ways. Common measures of aerobic capacity include the following:
- Borg Rating of Perceived Personhood (RPE) .
- Target heart rate: % of maximum heart rate (HR max) or Karvonen formula/heart rate reserve (HRR)
- Metabolic Equivalents (METS)
- Maximum oxygen consumption (VO2 max)
Each measure has guidelines on which parameters indicate vigorous moderate-intensity and low-intensity exercise. The table below provides a strength comparison of the various measurement methods. 
測量Low IntensityModer IntensityVigorous IntensityBorg RPE scale (0-10)< 55-6≥ 7HR max50- 63%64- 76%77-93%METS< 33-6> 6VO2 max20-39%40-59%60-84%
At moderate intensities, the patient’s heart beats faster, they feel warmer, and their breathing becomes more difficult. An example is brisk walking. 
During strenuous exercise, the patient warms up and sweats quickly, has more difficulty breathing, and has difficulty maintaining a conversation. 
The ultimate rule of thumb in exercise prescription is volume. Volume is the sum of intensity frequency duration and physical activity program duration.
Recommendations for frequency, duration and intensity have been developed for each type of exercise training. 
Type Frequency Intensity Time/Duration Example Aerobic (Endurance) 5 days/week Moderate 30 minutes (150 minutes per week) Vigorous Walking Jogging Swimming Hiking Cycling Resistance (Intensity) 2-3 days/week 60-70% of 1 rep max (novice) 40-50% of 1 rep max (sedentary seniors) 8-12 reps 2-4 Rest 2-3 minutes between sets Free weights Bodyweight exercises Calisthenics Flexibility 2-3 days/week until you feel tight. Hold 10-30 seconds 2-4 times, 60-second accumulation per stretch Ballistic Static Dynamic Proprioception Neuromuscular Balance 2-3 days/week None at all Sure. 20-30 minutes Tai Chi yoga
How these recommendations are applied depends on a variety of factors. When prescribing a program, health professionals must consider fitness level, fitness goals, exercise preferences, equipment availability, and other personal factors that may affect participation. For example, if a Patient or client with low fitness level An initial program may include low- to moderate-intensity aerobic exercise that is personally preferred and tailored to his or her schedule to encourage persistence. Additionally, the patient or client may have to work towards the recommended 150 minutes per week.
Apply FITT principles when prescribing exercise:
- How many times a week for an activity?
- For sedentary individuals, start with 2-3 days of cardio per week and increase to 5 days per week. Help pts build exercise routines.
- How hard to exert?
- People who are new to exercising should start at low intensity, but health changes occur at moderate exercise intensity
- What type of activities does the patient consent to?
- Should be pleasantly affordable and attainable
- How long in minutes
- This does not include warming up or cooling down.
- 10 minutes of physical activity can be accumulated throughout the day
- If walking is exercise – increase time before increasing intensity (uphill/walking at a faster pace)
Progression is the way to increase the frequency intensity and duration of an exercise program. Progression to an exercise program should be gradual to encourage participants to persevere and avoid injury. Recommendations for aerobic exercise include increasing Do 5 to 10 minute sessions every 1-2 weeks for the first 4-6 weeks.  Frequency and intensity can be done as tolerated. Total volume should be monitored, if necessary, to minimize adverse effects.
In the case of resistance exercise, it is beneficial to increase the number of repetitions before increasing the load. Once you reach your target range’s maximum reps, increase the load by approximately 5% so that you can perform without exceeding the lower limit of reps. 
Implications for Physiotherapist Practice
As exercise specialists throughout the lifespan, physical therapists play an important role in facilitating prescriptions and managing exercise programs. Home-based exercise and nutrition strategies have positive effects on frailty scores and physical fitness, a randomized controlled trial Manifestations in frail or debilitated older adults . In addition to being a tool for remedial activity limitation and participation in limiting activity limitation, exercise prescription should also be used to improve the health and well-being of patients and clients.
- Khan KM, Weller R, Blair SN. Prescribing exercise in primary care: ten practical steps on how to do it. British Medical Journal. 2011;343(d4141):806.
- World Health Organization. Global health risks: mortality and burden of disease attributable to selected major risks. Geneva: World Health Organization Press, 2009
- Balady GJ, Chaitman B, Driscoll D, Foster C, Froelicher E, Gordon N, Pate R, Rippe J, Bazzarre T. Recommendations for cardiovascular screening, staffing, and emergency policies at health/fitness facilities. Circulation. 1998 Jun 9;97(22):2283-93.
- American College of Sports Medicine. ACSM’s Guidelines for Exercise Testing and Prescription. 9th ed. Philadelphia (PA): Lippincott Williams & Wilkins; 2014.
- Noonan V, Dean E. Submaximal exercise testing: clinical application and interpretation. Physical therapy. 2000 Aug 1;80(8):782-807.
- Physical Activity Guidelines Advisory Committee. Physical Activity Guidelines Advisory Committee Report, 2008. Washington (DC); US Department of Health and Human Services; 2008.
- U.S. Department of Health and Human Services (1996). Physical Activity and Health: A Report of the Surgeon General. Atlanta GA. U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion.
- Motivate2Move. Exercise Medicine for Students.
- Center for Health Protection. Exercise Prescription Doctor’s Handbook. Hong Kong: Department of Health; 2012
- Hsieh TJ, Su SC, Chen CW, Kang YW, Hu MH, Hsu LL, Wu SY, Chen L, Chang HY, Chuang SY, Pan WH. Individualized home-based exercise and nutrition interventions improve frailty in older adults: a randomized controlled trial. International Journal of Behavioral Nutrition and Physical Activity. 2019 Dec 1;16(1):119.