Most people are aware that exercising regularly is one way to avoid developing high blood pressure and cardiac problems. What is not so common knowledge is that exercise can also be used as a form of treatment: to reduce the factors that cause angina, to improve the functioning of the heart and to avoid the recurrence of cardiac emergencies. 

Patients of angina are generally advised to undertake a program of low-intensity, aerobic exercise. Care is taken to ensure that during exercise, your heart rate is restricted to a fraction of the level at which you begin to feel symptoms of angina. This regimen may be instituted a few times a week, and then slowly increased in frequency. 

Effects of exercise on risk factors of angina: 

Aerobic exercise has been found to reduce blood pressure (both systolic and diastolic values)2. It also reduces resistance to the hormone insulin, thus helping control the sugar levels of diabetic patients3. In fact, an exercise regimen can help avert diabetes in those patients who are pre-diabetic3. 

The blood levels of body fats which contribute to coronary heart disease – including total cholesterol, triglycerides, triglyceride/HDL ratio3 4 and other parameters you may have seen in your blood reports – show improvement with exercise. 

Regular exercise may result in weight loss, or the prevention of weight gain3, and an improvement in Body Mass Index (BMI)4, which helps decide whether one’s weight is in the ideal range. However, patients must remember that the relationship between exercise and weight loss may vary from person to person3. 

Exercise training reduces the levels of a protein found in the blood that is associated with an increased risk of coronary heart disease3. This reduction is measurable by blood tests, and confirms the direct improvement by exercise on the course of the disease. 

One of the causes of coronary heart disease is the narrowing of the blood vessels that supply oxygen to your heart. When you exercise, the flow of blood in your blood vessels changes in a way that causes arteries to dilate3. The substance produced during exercise which causes this effect also protects patients against the tendency to form clots that can block these blood vessels3. 

Effects of exercise on angina itself:

Regular exercise has been shown to improve the capacity of the heart to respond to stresses, thus increasing the threshold at which angina occurs, leading to a reduction in the frequency of anginal attacks3. It also increases the ability of the heart to tolerate a prolonged period of reduced blood supply, thus reducing the chances of damage to the heart when this recurs3. 

Exercise also helps patients improve the pumping capacity of their hearts to some extent, and reduces chronically elevated heart rates5. 

And the bottom line is, exercise lowers the future risk of hospitalisation for angina, and of death due to coronary heart disease.6 

Types of exercise:

Aerobic exercises such as fast walking, jogging or swimming form the mainstay of exercise training in patients with coronary heart disease3. Each exercise session may typically consist of three components3:

• A 10-minute warm-up period consisting of stretching and low-level calisthenics
• A 20–30 minute period of aerobic exercise
• A 10-minute cool-down period involving low-level calisthenics and walking. 

All patients of angina should avoid physical exertion in very cold or hot, humid conditions that might increase the risk of suffering a cardiac emergency3. 

Should symptoms of angina be felt during exercise testing, your doctor may modify your exercise regimen according to the rate at which your heart beats during exercise, to avoid over-straining3. 

Not all exercise needs to involve a sport. Your doctor may also ask you to perform routine household tasks like gardening or house-cleaning for limited periods of time, which are also forms of exercise1. 

Before commencing an exercise regimen, a word of caution: 

Patients who intend to incorporate exercise as a part of their daily routine should first consult with their doctor to make sure that exercise does not add to their risk of developing a cardiac emergency; exercise increases the work of an already damaged heart, and should not be started without medical advice 1. 

High-risk patients, in particular, should undergo a formal cardiovascular assessment, which may include an exercise stress test3. This will enable your doctor to assess the capacity of your heart to tolerate and support exercise and to tailor your exercise regimen in a way that it strengthens your heart without damaging it further. Exercise levels should only be increased upto a point where you can tolerate it1.   

Lastly, patients must remember to increase their physical activity only gradually 1. Those who have led an entirely sedentary lifestyle, in particular, should avoid abruptly strenuous exercise; instead, they should slowly but surely increase their physical activity, to ensure the heart has time to adapt to this new demand3. Thus, they should begin with low-intensity activities before engaging in more vigorous physical activity. 

While modern medicine has developed procedures and medicines to combat angina, old-fashioned exercise is a multi-effect, cost-effective, patient-friendly way of combating angina.

References:  

1. Harrison’s Principles of Internal Medicine, Volume 2, Chapter 243: Ischemic Heart Disease
2. Whelton SP, Chin A, Xin X, He J. Effect of aerobic exercise on blood pressure: a meta-analysis of randomized, controlled trials. Ann Intern Med. 2002;136(7):493‐503.
3. Anil Nigam and Jean-Claude Tardif. The place of exercise in the patient with chronic stable angina. Heart Metab. 2008;38:34–37.
4. Gayda M, Brun C, Juneau M, Levesque S, Nigam A. Long-term cardiac rehabilitation and exercise training programs improve metabolic parameters in metabolic syndrome patients with and without coronary heart disease. Nutr Metab Cardiovasc Dis. 2008;18(2):142‐151
5. APA Walther, Claudia; Gielen, Stephan; Hambrecht, Rainer The Effect of Exercise Training on Endothelial Function in Cardiovascular Disease in Humans, Exercise and Sport Sciences Reviews: October 2004 – Volume 32 – Issue 4 – p 129-134
6. Anderson L, Oldridge N, Thompson DR, et al. Exercise-Based Cardiac Rehabilitation for Coronary Heart Disease: Cochrane Systematic Review and Meta-Analysis. J Am Coll Cardiol. 2016;67(1):1‐12