A sedentary lifestyle is one of the major risk factors for conditions such as hypertension, diabetes mellitus and high cholesterol for cardiovascular diseases. Each year about 250,000 deaths in the USA are attributable to a lack of regular physical activity. Evidence from a number of scientific studies shows that reducing these risk factors decreases the chance of having a heart attack and stroke. Regular exercise has a favorable effect on these risk factors and protects from cardiovascular diseases. With regular exercise as much as 30% to 40% reduction in cardiovascular events is possible by simply meeting current recommendations for life style modification.
Expert panels of physicians and scientists from various health organizations including the American Heart Association/American College of Cardiology, the Centers for Disease Control and Prevention, and the American College of Sports Medicine strongly recommend regular physical activity to reduce cardiovascular diseases and to maintain good health. It has been well proven scientifically that more active and physically fit individuals tend to develop less coronary artery disease (CAD) compared to their sedentary counterparts. If CAD develops in active or fit individuals, it usually occurs at a later age and tends to be less severe.
Benefits of Exercise:
A regular exercise program provides a myriad of health benefits for the entire body, including the heart and circulatory system as well as psychological well being.
- Regular exercise has many heart-healthy benefits. Regular exercise strengthens the heart muscle and helps to improve the heart's pumping and functioning ability. The flow of blood and hence the oxygen to the heart muscles via coronary arteries improves with regular exercise.
- Exercise helps to lower and regulate blood pressure, which in turn allows the heart to beat more effectively and move blood through the coronary arteries with greater ease.
- Cholesterol and other fat particles can build up over time on the insides of the coronary arteries, where it can impede blood flow and cause heart attacks. Regular exercise reduces “bad” cholesterol levels in the blood (the low-density lipoprotein, LDL), and can raise the “good” cholesterol (the high-density lipoprotein level, HDL).
- High blood sugar levels in patients with diabetes mellitus can damage the coronary arteries and promote the formation of coronary arterial plaques. Exercise helps to stabilize and reduce blood sugar levels, which in turn reduces the risk of heart disease.
- Exercise is also a very good remedy for weight loss.
- Exercise reduces stress, anxiety and depression and improves mental well being.
- Exercise also has protective effects for a number of non-cardiac chronic diseases, such as dependent diabetes, osteoporosis, and colon cancer. Regular exercise improves muscular strength and flexibility resulting in lower likelihood of developing back pain, bone osteoporosis and bone fractures and of disability, particularly in older age groups. In contrast, there is higher rate of cardiovascular events and a higher death rate in those individuals with low levels of physical fitness.
The effect of an exercise program on any single cardiac risk factor may generally be small; the overall effect of continued moderate exercise along with other life style modification (proper nutrition and smoking cessation) can be dramatic. Even mild increases in physical activity are associated with a decrease in mortality. Unfortunately despite this evidence, however, the vast majority of adults in the United States remain effectively sedentary.
Exercise for patients with heart disease:
Exercise improves muscular function and strength and body’s ability to perform better. This is particularly important for patients with cardiovascular disease, whose exercise capacity is usually lower than that of healthy individuals. Exercise improves blood flow to the heart muscles which results in more oxygen delivery to the heart muscles.
Patients with newly diagnosed heart disease are encouraged to participate in a structured exercise program, cardiac rehabilitation. Patients who participate in an exercise program report earlier return to work, improvements in their quality of life and improvement of their self-confidence, lower stress, and less anxiety. Among patients with a history of heart attack who participated in a formal exercise program, the death rate is reduced by 20% to 25%. This gives a clear message to patients with heart disease to participate in physical activity.
Types of exercise:
Physical exercises are grouped into three types:
- Flexibility and stretching exercises.
- Aerobic exercises, such as cycling, swimming, walking, skipping rope, rowing, running, hiking or playing tennis. These exercises improve cardiovascular fitness.
- Anaerobic exercises, such as weight training. This increases muscle strength.
Aerobic exercises are important for cardiovascular effects and overall general health.
How Much Exercise?
According to the National Institutes of Health (NIH), the maximum benefits of exercise will generally occur by engaging in at least 30 minutes of modest activity on most, preferably all, days of the week. Modest activity is defined as any activity that is similar in intensity to brisk walking at a rate of about 3 to 4 miles per hour. These can include activities such as cycling, walking or jogging, yard work, and swimming.
The 30 minutes of exercise does not necessarily need to be performed during one session. Repeated intermittent or shorter bouts of activity (3-4 sessions of 10 minutes each) have similar cardiovascular and other health benefits if performed with an accumulated duration of at least 30 minutes per day.
If one hasn’t exercised in a while, the heart, lungs, and muscles will be under more stress upon restart of exercise with full intensity. Therefore it is advised to start with shorter bouts of exercise, about 10 minutes or so, every other day and progress by three to five minute increments per week to achieve the target goal of 30 to 40 minutes. A lifestyle that includes physical activity from childhood throughout the adult years fosters good health and longevity.
Three phases of exercise:
1. Warm-up phase:
A good warm up at the beginning of the exercise helps to lessen the stress placed on the heart and muscles. The warm-up helps to slowly increase breathing, heart rate and body temperature. It also helps to improve flexibility and reduce muscle soreness. The warm-up phase lasts about five minutes and includes:
- Stretching exercises.
- Range of motion activities.
- Exercise activity at low intensity, for example, walking at a slow pace.
2. Conditioning phase:
This is the active exercise phase.
- Exercise must involve large muscle groups. Brisk walking, jogging, swimming, and cycling involve and strengthen several muscle groups.
- Intensity – Moderate intensity – enough to get heart rate and breathing to increase.
- Duration – 30 minutes of continuous exercise.
3. Cool-down phase:
This last phase allows the body to recover. Heart rate and blood pressure will return to near resting values. Cool-down does not mean sit down. It is important to slowly decrease the intensity of exercise over a period of 3-5 minutes. Sudden stop of exercise causes dizziness, light-headedness or palpitations.
It is important to include all three phases to avoid injury during exercise. One does not need to be a marathon runner or an elite athlete to derive significant benefits from physical activity. The greatest gains in terms of mortality are achieved when an individual goes from being sedentary to becoming moderately active.
Any Risks of Exercise?
Overall, exercise is very safe. There is a possible increased risk of having a cardiac-related complication among those who suffer from known heart disease. Therefore, it is recommended for such patients to start an exercise program after consultation with their physicians. Individuals who exercise regularly are much less likely to experience a problem during exercise. Although exercise is extremely safe, one should be aware of the warning signs or symptoms that may indicate a problem. One should seek medical attention if any of these symptoms occur during exercise: chest discomfort (pain or pressure in the chest, jaw, or neck), unusual shortness of breath, dizziness or light-headedness, or palpitation (sensations of heart beat skipping or thumping).
Exercise for beginners:
Begin a new exercise program gradually. Do not overdo it! Learn how to exercise safely and correctly. If possible, seek help from a certified exercise instructor who can develop a custom program to meet your health and fitness goals. If you are under 45 years of age and have no health issues, you can start exercise with daily walks and gradually increase the intensity of exercise level over a period of couple of weeks. If you currently have heart disease or are over 45 years of age or have 2 or more risk factors (such as family history of heart disease before age 55, cigarette smoking, high blood pressure, abnormal cholesterol levels, diabetes), you should consult your physician before starting an exercise program.
Regular exercise can improve the quality of life and reduce the risks of developing heart disease, hypertension, some cancers and diabetes among people of all ages. Regular exercise will also enhance mental well-being, reduce stress and anxiety and promotes healthy musculoskeletal function throughout life.