Physical inactivity – a risk factor among people with healthy hearts
Evidence (1;2) shows that physical inactivity is an important risk factor for heart disease among both men and women. Studies show an association between low aerobic capacity and the risk of death and heart disease. Evidence (3–5) further indicates that increasing physical activity reduces this risk.
Exercise training and survival among patients with heart disease
Several meta-analyses (6–10) show that exercise training among patients with known ischaemic heart disease reduces the mortality from heart disease. Mortality from heart disease declines by an estimated 31% and all-cause mortality by 27% compared with patients with heart disease not undergoing exercise training (8). A small study (11) demonstrated reduced mortality and hospital admissions among patients with congestive heart failure undergoing exercise training, but this needs to be confirmed.
Improving physical functioning and compliance
People with heart disease have poorer physical functioning than people with healthy hearts; this applies to men and women and to young and old people (12). The poorer functioning can be attributed to reduced aerobic capacity and to the anxiety about exercising after an acute cardiac event. Strong evidence (5) indicates that exercise training improves the physical capacity for work among people with healthy hearts and heart disease. Although supervised exercise training increases people’s aerobic capacity, this does not necessarily ensure a high level of physical activity in the long term. Patient compliance with both supervised and unsupervised exercise training is quite low: in one trial (13), only about half were more physically active after one year than they were before rehabilitation, and this dropped to 13% after three years. Knowledge of how to optimally organize exercise training to sustain the effect over a long time period is inadequate.
Physical activity as part of comprehensive cardiac rehabilitation improves the quality of life of patients with heart disease (8;14), and Studies indicate that the effect of exercise training supplements the pharmaceutical treatment of mild and moderately severe depression (15).
Modifiable risk factors
Basic research on the effects of exercise training shows that exercise training substantially reduces blood pressure and increases serum high-density lipoproteins. Large intervention studies (8;16) could not reproduce this effect, however. Exercise training improves the regulation of blood sugar among people with diabetes (17), and lifestyle intervention including exercise training reduces the risk of developing type 2 diabetes among people with impaired glucose tolerance (18–20). Exercise training alone has limited effects on weight loss (21); adding dietary intervention to exercise training increases the effect.
There is a consensus in Denmark and elsewhere that exercise training is an important aspect of the overall rehabilitation of patients with chronic congestive heart failure (22), patients with ischaemic heart disease (23–25) and patients at high risk of ischaemic heart disease (5;26). According to the Hospital System Act of 2001, hospitals in Denmark are legally obligated to offer a rehabilitation plan to patients who have a medically justified need.
The purposes of exercise training in the comprehensive cardiac rehabilitation programme are to teach patients about the relationship between physical activity and heart disease, to increase patients’ aerobic capacity and to test their mental and physical reactions in realistic exercise situations with the aim of getting patients physically active in daily life.
The supervised exercise training in the comprehensive cardiac rehabilitation programme is structured based on several principles described in this section.
Six weeks of supervised exercise training
Current European recommendations (27) say that supervised exercise training should last 8–12 weeks, but the length of supervised exercise training varies substantially between cardiac centres and countries (28). The comprehensive cardiac rehabilitation programme offers all patients 6 weeks of supervised exercise training, which can be extended if needed. The need for further supervised exercise training is assessed based on an aerobic functioning test and an evaluation consultation.
Individual exercise training level
Strong evidence indicates that patients with heart disease can improve their aerobic capacity. Effective exercise improves cardiovascular capacity or strength. An exercise training session is optimally 90 minutes long. Of this, at least 30 minutes should be at 60–70% of the maximum heart rate for each patient. This is equivalent to the patient exercising hard but still being able to converse (22;29–31).
The intensity of exercise among patients with heart disease is recommended to be 60–80% of the maximum heart rate (30). The comprehensive cardiac rehabilitation programme determines the patients’ theoretical maximum heart rate by carrying out a symptom-limited aerobic functioning test on a stationary cycle (Chapter 4). If such a test cannot be performed, the theoretical maximum heart rate is determined based on the formula: estimated theoretical maximum heart rate = 208 – (0.7 × age). This formula has been validated in a population including a large group of elderly people (32). The comprehensive cardiac rehabilitation programme sets the maximum recommended heart rate at 70–80% of the theoretical maximum obtained through a test of aerobic functioning or estimation.
|Calculated theoretical maximum heart rate for a 65-year-old|
|Estimated theoretical maximum heart rate = 208 – (0.7 × 65)
= 162 beats per minute
|Exercise training: 30 minutes at 60–70% of 162 beats per minute
= 97–113 beats per minute
The maximum heart rate to be attained in exercise training is reduced individually for patients who have strain-induced angina pectoris, arrhythmia, an implantable cardioverter defibrillator, heart transplantation, congestive heart failure (NYHA class III) or obesity and patients who get very little exercise.
The exercise training programme for these patients is planned based on a precautionary principle. Exercise training is induced at about 50% of the theoretical maximum heart rate (under the maximum conversational level) with short intervals, frequent breaks and slow progression (22).
The comprehensive cardiac rehabilitation programme uses heart rate monitoring and the guideline of a conversational maximum to simultaneously assess patient’s individual exercise intensity. The exercise heart rate is established based on these principles depending on the results of the aerobic functioning test, the variation in the patient’s heart rate and the clinical assessment by the physical therapist of the patient’s level of aerobic functioning.
Activity in daily life
The National Board of Health recommends at least 30 minutes of moderate physical activity daily for adults (4;5), and the exercise training in the comprehensive cardiac rehabilitation programme is based on this principle. According to the recommendation, all forms of physical activity in the activities of daily living are included, even less intensive physical activities that do not influence maximum oxygen uptake substantially but are still considered to promote health. An example of moderate activity is rapid walking in which the respiration frequency is elevated but conversation is possible. Accumulated activity in daily life is just as health-promoting as continuous activity and perhaps even more so based on a behavioural perspective.
Exercise training can improve general cardiovascular (aerobic) capacity or muscle strength. The physical capacity of many patients with heart disease is so low that almost any type of physical activity will influence both aerobic capacity and muscle strength (31;35). Exercise training in the comprehensive cardiac rehabilitation programme is mainly group sessions and based on everyday activities such as walking, climbing stairs and cycling. No special clothes and equipment are necessary.The exercise training is performed both outdoors and indoors.
Normal walking insufficiently challenges the cardiovascular system among welltreated patients with heart disease but without congestive heart failure, and especially patients with a high risk of heart disease. The comprehensive cardiac rehabilitation programme therefore also uses walking-sticks for outdoor walking (see the model photograph in Chapter 9). The walking-stick activates the upper extremities, which ensures exercise for the entire body. Exercise balls, balance boards and aerobic elastics for light muscular strength training are also used.
The exercise training is intended to be easy to perform, to be easy to implement in daily life and to make the body feel good. The specific exercises are chosen based on the extent to which the exercises are relevant to each patient. Easier, less expensive and more relevant exercises are more likely to make patients choose to be more physically active in daily life in the maintenance phase after the 6-week intensive exercise training programme.
Exercise training is individually tailored, considering diagnosis, individual differences in physical capacity, motivation for exercise, musculoskeletal strengths and weaknesses and the patient’s daily life. Patients receive individual feedback, and individual patients are supported in fulfilling their specific desires. The physical therapist emphasizes involving patients from the first session as co-planners of their exercise training. The physical therapist can easily identify the patients who lack motivation to begin exercise training by either allowing each patient to choose the type of exercise training or making a collective agreement on the exercise training each day.
During the entire programme, the patients are encouraged to exercise at home between the two weekly exercise training sessions in accordance with the recommendations on daily exercise of the National Board of Health (4;33).
Voluntary effort and breaks when needed
Exercise training in the comprehensive cardiac rehabilitation programme is based on the principle of voluntary effort and taking breaks when needed; experience shows that patients are more motivated to exercise if they know that they can take breaks than if the exercise training is very strict. Further, the breaks ensure that patients do not overexert themselves and exceed their capacity.
Warming up and cooling down
Before exercising, the patients warm up for at least 10 minutes. After exercising, the patients cool down either by gradually reducing the strain on the stationary cycle, through relaxation (visualization, breathing exercises or meditative exercises) or by stretching muscles. This avoids sudden cardiovascular strain, which can be manifested as angina pectoris, changes in blood pressure, peripheral tiredness and, occasionally, arrhythmia.
Individual evaluation and feedback
For each patient, the heart rate data from each day’s exercise training is registered, and the patients rate their perceived exertion based on the Borg Scale from 6 to 20, the subjective sense of exercise training on a scale from 1 to 5 and any angina on the Borg Angina Scale from 1 to 10 (the evaluation scales used for individual evaluation are available in Danish at www.CardiacRehabilitation.dk). The physical therapist also registers any extraordinary events in connection with exercise training (such as falls or dizziness). Based on the patients’ ratings and the heart rate data for that day, the physical therapist and the patient discuss how exercise training went and adjust and adapt the exercise training when necessary. The effect of exercise training is assessed at the three-month and 12-month follow-up consultations, at which a test of aerobic functioning is conducted (Chapter 4).
Exercise training for patients with congestive heart failure
Exercise training for patients with symptoms of congestive heart failure (NYHA classes II and III) follows the same principles as for other patients with heart disease. Patients must be undergoing pharmaceutical treatment and must not have symptoms at rest (NYHA class VI), which contraindicates exercise training. In accordance with the European recommendations (22) and the principle of precaution, the exercise programme is set with a lower intensity of exercise, typically 50% of the theoretical maximum heart rate.The exercise training also has briefer intervals, many breaks and gradual progression based on the progress in exercising of each patient. Patients with congestive heart failure exercise together with the other patients and also have a heart rate monitor. Patients with congestive heart failure typically exercise longer than 6 weeks in the comprehensive cardiac rehabilitation programme.
Exercise training of patients with type 2 diabetes
The exercise training of patients with type 2 diabetes follows the same principles as exercise training for other patients with heart disease but considers any diabetes selfcare and regulation. Unregulated diabetes is a relative contraindication for exercise training. The patients are informed that exercise training reduces any insulin dose required, and measuring their blood sugar before and after exercise training has great psychological significance and increases the patients’ motivation for exercise training.
Group exercise training
Group exercise training comprises 12 exercise sessions of 1.5 hours. The exercise training changes from considerable supervision to self-managed exercise training during the 6 weeks.
First session: The physical therapist informs the patients of the purpose and principles of exercise training in the comprehensive cardiac rehabilitation programme, the roles of the physical therapist and the patients and the use of various exercise facilities. Questions are clarified and the practical exercise training can begin. Through the initial individual consultation, the aerobic functioning test and the patient record, the physical therapist is thoroughly oriented about the patient’s illness history, lifestyle and psychosocial state and biochemical data and pharmaceutical treatment, which can influence the level of physical activity.
The patients are instructed on general procedures for exercise training at the Cardiac Rehabilitation Unit and at home.
|General procedures for exercise training for patients with heart disease|
Patients are instructed to be very attentive to signs of excessive intensity.
|Clinical signs of excessive exercise intensity|
Finally, patients are encouraged to always ensure gradual progression: they are told that they should take one break too many instead of one too few. Patients are advised that the body must have time to recuperate. Appropriate exercise allows recuperation within 24 hours. If exercise requires longer recuperation, the intensity is excessive.
The first exercise is usually ball training in a room, which is used to test patients’ motor skills, breathlessness, any exertion-caused angina pectoris and functional capacity and the patient’s ability to cooperate and take initiatives.The physical therapist informs and supervises when needed based on the impression of the individual patient and the group. This exercise brings the patients together and supports a positive process of group dynamics. Then the physical therapist introduces stationary cycles and perhaps step benches (simulated stair-climbing), which are each performed for a maximum of 5–10 minutes. The step benches are used to prepare patients for actual stairclimbing and for patients who need specific training in climbing stairs.
Second session: In the second session, the physical therapist introduces heart rate monitors, and the optimum exercising heart rate is determined based on the aerobic functioning test. The physical therapist tests the patients’ ability to climb stairs and to use a step bench. All patients start slowly, since climbing stairs is a relatively strenuous activity. At the end, the individual patients evaluate the group exercise training that day.
During the second week, the patients have the opportunity to try the facilities and the physical therapist has had time to get an impression of each patient. More specific initiatives and individual tasks can therefore be tackled. The physical therapist still has a managing function and serves more as a instructor than as a supervisor, depending on how well the group works together. The exercise sessions become longer; the time spent exercising, the intensity and the choice of activities are optimized continually. However, the physical therapist does not yet attempt to get patients to exercise strenuously for a total of 30 minutes.
The physical therapist manages the exercise training less in the third week.The physical therapist has taken on a more supportive function, and patients can consult the physical therapist when they need to. The physical therapist attempts to get the patients to fully use the exercise time, reach the agreed intensity, choose exercises and reach the effective exercise time in accordance with the planned goals.
The exercise facilities of the Cardiac Rehabilitation Unit now function as a heart fitness centre in which the patients exercise with considerable autonomy. The patients have begun to acquire a routine in exercising, and most can feel the physical progress. Patients who have difficulty with exercise training get extra support to become optimally active.
Exercising in the community environment (phase III cardiac rehabilitation): Patients are encouraged to continue the daily physical activity at the same level after they end the 6-week supervised exercise training programme at the Cardiac Rehabilitation Unit. The physical therapist presents suitable exercise opportunities in the local area in the theoretical education (Chapter 5) and though the activity folder (Chapter 9). Nevertheless, appropriate exercise opportunities of this type are very scarce in the community environment. Finally, the patients are reminded about the activities of the Danish Heart Foundation in local areas, which are advertised in local newspapers, the newsletter of the Foundation (HjerteNyt) and at the web site of the Foundation (www.hjerteforening.dk).
Exercise training in open groups
The cardiac rehabilitation programme allows patients to participate in open groups. These groups are mainly for patients who need extra supervised exercise training, which is assessed at the follow-up evaluation consultation with the physical therapist. Patients eligible for the open groups include patients in individual programmes, patients with special needs and patients who have participated well either individually or in a group but have not achieved the expected physical or mental progress. This exercise training follows the general principles and is evaluated after another 6 weeks. The interprofessional conference decides who will participate in an open group.
Exercise training in an individual programme
Patients who have problems participating under normal conditions in the group sessions are offered individual guidance and exercise training. In practice, patients who receive individual exercise training are treated precisely the same as group participants except that the aspect of group dynamics is lacking.
After 6 weeks of exercise training
The purpose of the second individual consultation with the physical therapist is to assess, through discussion and an aerobic functioning test, whether patients have achieved their overall goals. Another aim is to make the transition from intensive exercise training to normal daily activities as flexible and effective as possible. The physical therapist assesses whether patients need help in remaining physically active after the treatment period and whether they might benefit from further supervised exercise training.
After 12 months
Patients have been responsible for their own exercise for about 9 months. The third and final aerobic functioning test shows whether patients have been able to realize the goals agreed with the physical therapist. The physical therapist discusses the patients’ physical activity level in daily life based on their assessment of their situation and the aerobic functioning test. Patients who believe that they have achieved their goals and for whom the aerobic functioning test supports this have successfully changed their exercise habits. If this is not the case, patients should ideally be referred to a supervised programme in primary health care, although this is not currently possible within the public health care system in the local area surrounding Bispebjerg Hospital.
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