Physical Activity Prescription for Cardiovascular Prevention

Definition and Clinical Rationale

Physical activity comprises bodily movement that increases energy expenditure, including walking, household tasks, active commuting and recreational activities. Exercise is a more structured form of physical activity undertaken to maintain or improve physical fitness.

Regular physical activity is a central component of cardiovascular prevention and treatment. It is associated with lower cardiovascular and all-cause mortality and with reduced incidence or burden of hypertension, type 2 diabetes, coronary disease, stroke, peripheral arterial disease, heart failure, depression, dementia and osteoporosis. It also improves functional capacity, skeletal health, muscular strength, quality of life and psychological well-being.

Physical inactivity is itself a major cardiovascular risk factor. Sedentary behaviour may confer risk even in individuals who achieve recommended exercise volumes; therefore, prevention strategies should address both increasing activity and reducing time spent sitting.

The relationship between activity and cardiovascular benefit is curvilinear. The largest relative improvement occurs when an inactive person becomes even modestly active, while additional activity continues to confer benefit with progressively smaller incremental effects. Some activity is preferable to none, and benefit is observed below the conventional minimum target.

Recommended Activity Volume and Intensity

For adults, the principal preventive target is:

• 150–300 minutes per week of moderate-intensity aerobic activity; or

• 75–150 minutes per week of vigorous-intensity aerobic activity; or

• An equivalent combination of moderate- and vigorous-intensity activity.

Muscle-strengthening exercise should additionally be performed on at least 2 days each week. Activities need not be undertaken in bouts of at least 10 minutes; shorter episodes also contribute to health. Spreading activity across the week may reduce musculoskeletal injury risk.

Examples include brisk walking, jogging, swimming and cycling. Activities should be selected according to the individual’s preferences, functional status and daily routine, because enjoyable and convenient activities are more likely to be maintained.

For older adults, an achievable programme should incorporate four domains:

• Aerobic activity

• Strength training

• Balance exercises

• Flexibility exercises

Walking, yoga and gardening may provide useful activity for individuals who are reluctant to undertake formal exercise. Increasing movement during daily living is a practical initial strategy.

Assessment Before Prescription

Physical activity should be assessed and prescribed using the components of:

• Frequency

• Intensity

• Time or duration

• Type

• Progression

The prescription should be individualized rather than based solely on an age-based target. Relevant considerations include cardiovascular disease, exercise capacity, symptoms, comorbidities, previous activity level, psychological factors, goals and the intended setting.

Pre-participation screening should follow applicable cardiovascular exercise-screening guidance. In individuals with cardiovascular disease, an exercise test may provide objective information on peak exercise capacity and the heart-rate, blood-pressure and symptom responses to exertion. These data can guide domestic, occupational, recreational and athletic activity counselling, although they do not fully reproduce prolonged activity or environmental stresses such as heat, humidity, altitude or wind.

A gradual progression is particularly important in previously sedentary individuals and those with chronic disease. Increasing frequency and duration before substantially increasing intensity may reduce overuse injuries. The practical principle is to begin at a low level and progress slowly.

Exercise Intensity

Intensity may be prescribed using several complementary approaches.

Heart-rate-based methods

For patients with cardiovascular disease, dynamic aerobic exercise may be prescribed at approximately 40–80% of peak exercise capacity using the heart-rate-reserve method. In patients who have undergone cardiopulmonary exercise testing, the heart rate corresponding to 40–80% of measured peak oxygen consumption may be used.

A simpler approach is exercise at approximately 70–85% of maximal measured heart rate. Heart rate should be interpreted together with symptoms and perceived exertion.

In patients demonstrating an ischaemic response, the exercise heart rate should be set at least 10 beats below the heart rate at which typical angina or ischaemic ST-segment depression develops.

Perceived exertion

The Borg rating of perceived exertion may be used to individualize intensity. A target of 11–16 on the 6–20 scale is described for patients with cardiovascular disease.

Perceived exertion is particularly useful when heart-rate responses are altered by disease, medication or environmental conditions. Symptoms should remain an important determinant of exercise intensity.

Metabolic and functional measures

Exercise testing can quantify peak exercise capacity in metabolic equivalents and assess responses at peak and submaximal workloads. These data can then be matched to the demands of specific activities. Such an approach is useful for advising patients about practical tasks, although it cannot establish the ability to sustain a workload for prolonged periods.

Interval training

Aerobic interval training has been described as alternating approximately 3–4-minute periods at 90–95% of peak heart rate with moderate-intensity periods at 60–70% of peak heart rate. A session of approximately 40 minutes, including warm-up and cool-down, performed three times weekly has been associated with greater improvements in peak oxygen consumption, endothelial function and metabolic parameters than standard continuous moderate-intensity exercise.

Because this approach is more demanding, it is best considered selectively and within supervised cardiac rehabilitation for appropriate patients.

Exercise Prescription in Cardiovascular Disease

General cardiovascular disease

Virtually all patients with cardiovascular disease should be encouraged to remain physically active, exercise and preserve physical fitness. Exercise is associated with improved cardiovascular and mental health, lower cardiovascular mortality, better exercise capacity and improved quality of life.

A symptom-limited ECG stress test may also help assess the safety of resistance training. During clinical, non-body-building strength training, the maximal heart-rate–blood-pressure product is rarely greater than that attained during the stress test.

For aerobic training in patients with cardiovascular disease, the usual goal is:

• Duration: 20–60 minutes per session

• Frequency: 3–5 days per week

• Intensity: individualized using exercise-test findings, heart rate and perceived exertion

• Modality: rhythmic activity involving large muscle groups of the upper and lower limbs

Examples of equipment include treadmills, cycle ergometers and elliptical trainers.

Coronary disease and coronary heart disease

Patients with coronary disease should generally be encouraged to undertake physical activity and exercise. Benefits include improved cardiovascular and mental health, lower cardiovascular mortality, better quality of life, greater exercise capacity and reduced likelihood of obesity and type 2 diabetes.

The potential for exercise to precipitate a sudden cardiac event is recognized, particularly with vigorous or unaccustomed activity. However, the overall risk of adverse events is very low, and the cardiovascular benefits of regular activity outweigh the inherent risks. Activity restriction does not necessarily reduce sudden-death risk in patients with congenital heart disease, as many sudden deaths occur at rest rather than during exercise.

Heart failure with reduced or mid-range ejection fraction

Exercise discussions and an individualized prescription are recommended regularly for all patients with heart failure. In stable patients, exercise-based cardiac rehabilitation is recommended to improve exercise capacity and quality of life and to reduce hospital readmissions.

Low- to moderate-intensity recreational sport and structured exercise programmes may be considered in stable individuals. High-intensity interval training may be considered in low-risk patients wishing to return to high-intensity aerobic or mixed endurance sport. Non-competitive, low-intensity recreational skill-based sports may also be considered in stable, optimally treated patients when tolerated.

High-intensity power and endurance sports are not recommended in patients with heart failure with reduced ejection fraction, irrespective of symptoms.

Clinical reassessment should be considered when exercise intensity is increased beyond the patient’s established level. Motivational and psychological support, together with specific advice on progression, may improve participation.

Peripheral arterial disease

Few patients with chronic symptomatic peripheral arterial disease achieve the physical activity levels recommended for reducing major adverse cardiovascular events. Observational evidence indicates that adherence to activity time–intensity targets is associated with better ambulation, quality of life and vascular outcomes.

Aortic disease

Physical activity may reduce resting heart rate and blood pressure and thereby lower the risk of aortic complications. Evidence concerning exercise and sports in aortic disease is limited. Decisions should therefore be individualized and based on risk stratification.

Inflammatory myopericardial syndromes

Patients with active inflammatory myopericardial disease should restrict physical activity. Exercise may aggravate myocardial or pericardial inflammation, potentially through tachycardia-mediated mechanisms. Heart-rate control may improve symptom control, and empirical β-blocker use has been associated with better control of pericarditis symptoms in observational studies.

During acute myocarditis, complete rest is advised because exercise has been associated with arrhythmias and sudden cardiac death. Recovery should be followed with clinical assessment, rhythm monitoring, laboratory testing and multimodality imaging.

Return to exercise should be individualized rather than determined by an arbitrary fixed period. Complete clinical remission requires normalization of symptoms, biomarkers and imaging. The programme should account for whether the patient is an athlete or non-athlete and for the type of exercise planned.

Atrial fibrillation

Moderate aerobic physical activity may reduce the risk of new-onset atrial fibrillation. Conversely, atrial fibrillation incidence appears to be increased among athletes, with observational evidence indicating a 2.5-fold higher risk than in non-athlete controls. Exercise prescriptions should therefore distinguish moderate recreational activity from sustained high-level athletic training.

Congenital heart disease

Patients with congenital heart disease should generally be encouraged to undertake regular physical activity. Even those with complex circulation, including Fontan physiology, may benefit from exercise.

Despite concern regarding exercise-related sudden death, the risk during exercise is very low in adults with congenital heart disease. Only approximately 30% achieve recommended activity levels, partly because of restrictive advice. Exercise counselling should therefore avoid unnecessary limitation while remaining individualized to the cardiovascular condition.

Safety and Adverse Events

The most frequent adverse events associated with physical activity are musculoskeletal injuries. Risk increases with the amount and intensity of activity and can be reduced by:

• Choosing activity appropriate to current fitness

• Increasing activity gradually

• Using protective equipment

• Selecting safe environments

• Avoiding unaccustomed vigorous exertion

• Incorporating an appropriate progression of duration, frequency and intensity

A sudden cardiac event, including sudden death during or shortly after exercise, is among the most serious potential complications but is extremely rare. Vigorous activity can precipitate such events, particularly when unaccustomed or undertaken by individuals with advanced cardiovascular disease.

Light- to moderate-intensity activity, such as walking for 5–15 minutes per session two or three times weekly, carries no known increased risk of sudden severe cardiac events compared with less intense activity or rest. Across the whole day, regularly active individuals have lower overall cardiovascular risk than inactive individuals, despite the transient increase in risk during exertion.

Behavioural Strategies and Adherence

Exercise counselling is more effective when it is practical, individualized and behaviourally supported. Useful interventions include:

• Collaborative goal-setting

• Periodic reassessment and revision of goals

• Self-monitoring

• Feedback on progress

• Wearable activity trackers

• Integration of activity into daily routines

• Selection of activities that the individual enjoys

A multidisciplinary behavioural approach should accompany appropriate pharmacological management in cardiovascular prevention. Multidisciplinary exercise-based programmes improve cardiovascular risk profiles and reduce cardiovascular mortality.

Home-based cardiac rehabilitation and mobile-health interventions may improve long-term adherence to healthy behaviours and reduce hospitalizations or cardiac events. Psychological and motivational support is particularly relevant in heart failure, coronary disease and patients concerned about recurrent cardiovascular events or disease progression.

Exercise also benefits mental health. It can improve mood and reduce stress, and in coronary disease with depression it may be an effective component of treatment when combined with antidepressants and psychotherapy. In heart failure, exercise training has been associated with modest improvements in depressive symptoms, although the modality and duration should be adapted to functional capacity and whether supervision is required.

Cardiac Rehabilitation

Exercise-based cardiac rehabilitation is recommended for all stable individuals with heart failure with reduced or mid-range ejection fraction. It is intended to improve exercise capacity and quality of life and reduce hospital readmission frequency.

In patients with cardiovascular disease, supervised programmes provide an appropriate setting for individualized intensity prescription, monitoring of symptoms and cardiovascular responses, and consideration of interval training. A structured programme should include warm-up and cool-down, an appropriate exercise modality, and planned progression.

Beyond the annual cardiovascular assessment, reassessment should be considered when exercise intensity is increased. Exercise and sports discussions should be documented, particularly when patients with cardiovascular disease seek participation in strenuous or competitive activities.

Guideline-Based Recommendations

Prognosis and Follow-up

Regular physical activity is associated with lower cardiovascular and all-cause mortality, reduced cardiovascular morbidity, improved functional capacity and better quality of life. Mortality risk declines across increasing activity volumes, with the steepest improvement among the least active individuals. Benefits continue above the minimum recommended volume, although the incremental reduction becomes smaller.

Daily step counts below 10,000 can still be associated with cardiovascular and mortality benefit. In adults aged 60 years or older, approximately 6000–9000 steps per day has been associated with substantially lower future cardiovascular-event risk than approximately 2000 steps per day. The activity level associated with the greatest observed reduction in mortality varies by age.

Follow-up should be proportionate to disease severity and the planned activity. It should include reassessment of symptoms, exercise tolerance, adherence, psychosocial barriers and cardiovascular responses when clinically indicated. Patients with inflammatory myopericardial disease require clinical, rhythm, laboratory and imaging follow-up before exercise is resumed. Patients with heart failure should be reassessed when increasing exercise intensity, while those participating in strenuous or competitive sport require individualized risk assessment and documented shared decision-making.