Module E, Annotation H: Prescribe Exercise Program And Level Of Monitoring

OBJECTIVE

Prescribe exercise program based on risk status.

ANNOTATION

Exercise programs may be supervised or unsupervised.

Supervised group exercise sessions, such as provided in outpatient cardiac rehabilitation programs,
are recommended initially to enhance the exercise educational process, ensure that the patient is
tolerating the exercise program, confirm progress, and provide medical supervision, particularly in
high- to intermediate-risk patients.
Unsupervised home exercise programs are acceptable for persons at low risk who are motivated,
understand the basic principles of exercise training, and can reliably report untoward effects of
exercise.

It is desirable that intermediate- to high-risk patients have medically supervised cardiac rehabilitation and reevaluation to "re-stratify" them to a lower level of risk (see Table 3). Most patients in secondary prevention can soon be re-stratified as low risk and can implement their exercise prescription at home or in a community program. In addition, secondary prevention efforts should be aggressive. There is considerable evidence that multiple risk-factor reduction in patients with known coronary artery disease stabilizes atherosclerotic plaque, improves endothelial function, and reduces risk for clinical events.

Table 3. Prescribed Exercise and Monitoring
Risk for Exercise- Induced Event	Monitored by Telemetry ^(a)	Supervised by Professionals	Home Exercise Program
High Risk	Yes	Yes	Not advised initially
Intermediate Risk	Yes	Yes	Not advised initially
Low Risk	Optional	Yes^(b)	Yes

^(a) Telemetry-monitored exercise is recommended if an outpatient cardiac rehabilitation program is available.
^(b) Supervised exercise is recommended if it is determined that a patient will not adhere to a home exercise program.

DISCUSSION

Some patients who are at low risk for an exercise-induced event will fail a home exercise program because of poor adherence to physician recommendations. Patients who are at increased risk for non-adherence include the following:

Tobacco users
Overweight patients (i.e., body mass index (BMI) >27)
Blue collar occupation and low education
Patients with sedentary occupations
Patients with low leisure time activities
Patients who perceive their health status as poor

Before deciding upon a home exercise program, the physician should make an individualized assessment of the likelihood that the patient will comply with the prescribed program. For those patients who are felt to be at high risk for non-adherence, a more formal and closely supervised program is appropriate, provided that such programs are available.

For more resources for cardiac rehabilitation program development, refer to the American Association of Cardiovascular and Pulmonary Rehabilitation (AACVPR) Guidelines for Cardiac Rehabilitation Programs, 3rd Edition (1999).

General principles of exercise prescription for a home exercise program, if outpatient cardiac rehabilitation is not available or necessary

TYPES OF EXERCISE

An exercise program should include aerobic and resistance training. Aerobic exercise includes proper intensity, duration, and frequency.

Aerobic

Aerobic exercises, also referred to as dynamic exercise, utilize large muscle groups and are continuous in movement (e.g., walking, jogging, cycling, swimming, and use of stationary exercise equipment such as a treadmill, stationary cycle, or rowing machine). Low-impact aerobic activity is advisable to minimize risk of injury associated with exercise.

Resistance

Resistance training (also referred to as static or strength training) improves skeletal muscle strength and endurance in clinically stable coronary patients. Training measures designed to increase skeletal muscle strength can safely be included in the exercise-based rehabilitation of clinically stable coronary patients, when appropriate instruction and surveillance are provided. Patients may perform after aerobic exercise session or on alternate exercise days.

Upper-body strengthening with light weights (i.e., 2 to 10 pound dumbbells) is recommended for all patients. Selected low-risk patients may proceed to heavier resistance-training equipment (e.g., Universal Gym or Nautilus) after at least 4 to 6 weeks of aerobic conditioning. Training emphasis is based on low weight and increased repetition.

EXERCISE INTENSITY

Refer to Table 4 for assistance in prescribing exercise intensity for patients. These percentages are to be used as target heart rate ranges for exercise intensity.

Table 4. Exercise Intensity Recommendations
Condition	Target Heart Rate
Early weeks of exercise	60% to 70% of maximal heart rate achieved on an EST
Progression of exercise (by 6 to 12 weeks into exercise program)	75% to 85% of maximal heart rate achieved on an EST
Exception: Angina or silent ischemia	Exercise heart rate should be 10 to 20 beats below the angina/ischemic threshold
Upper limit of exercise intensity	Maximal heart rate achieved on an EST

Patients should adhere to the intensity boundaries prescribed and should learn to monitor their pulse while exercising at home. Commercially available heart rate monitors can be helpful for this purpose (e.g., Polar Heart Rate Monitor).

Exercise intensity parameters are also based on the patient's subjective measure of perceived exertion. The Borg Scale of Perceived Exertion is widely used for obtaining this measure (see Table 5). There is a linear correlation between the exercise training heart rate and the rate of perceived exertion (see Table 6).

Table 5. Borg Scale of Perceived Exertion (Borg,1982)
Condition		Target Heart Rate
6		0	Nothing
7	Very, very light	0.5	Very, very weak (just noticeable)
8		1	Very weak
9	Very light	2	Weak (light)
10		3	Moderate
11	Fairly light	4	Somewhat strong
12		5	Strong (heavy)
13	Somewhat hard	6
14		7	Very strong
15	Hard	8
16		9
17	Very hard	10	Very, very strong (almost maximum)
18
19	Very, very hard		Maximum
20

Table 6. Rate of Perceived Exertion
Target Exercise Heart Rate	Rate of Perceived Exertion*	Intensity
40% to 60% of maximal heart rate achieved on an EST	<12	Light
60% to 70% of maximal heart rate achieved on an EST	12-13	Moderate
75% to 85% of maximal heart rate achieved on an EST	14-16	High
90% to 100% of maximal heart rate achieved on an EST	>16	Very high

* See Borg Scale of perceived exertion (1982)

Exercise intensity can progress as tolerance is demonstrated. An appropriate initial intensity of training for moderately physically active patients is 60% to 70% of the maximal heart rate achieved on EST or perceived exertion of 12 to 13.

EXERCISE DURATION

Optimal exercise duration is 20 to 60 minutes of continuous aerobic exercise. For deconditioned patients and patients with a 3 to 5 MET capacity, multiple sessions of shorter duration (i.e., 10 to 20 minutes) may be necessary, with 4 hours between sessions.

EXERCISE FREQUENCY

Exercise frequency for patients with >5 MET capacity is 3 to 5 exercise sessions per week. For patients with 3 to 5 MET capacity, multiple sessions (i.e., 2 times per day) are appropriate (refer to Appendix E-1: Sample Form for Cardiac Rehabilitation Treatment Plan.)

EXERCISE LOG

It is advisable to provide the patient with an exercise log for the purpose of measuring improvement in exercise capacity and tolerance. This also provides the patient with exercise program tracking data (see Appendix E-4).