Exercise has been proven to bring numerous health benefits, especially for cardiovascular health. The issue at hand is that exercise needs to be personalized, performed correctly, and scientifically to truly benefit cardiovascular health while minimizing the risk of adverse events during training, especially in individuals with undiagnosed cardiovascular conditions.
General Introduction
Physical activity refers to any bodily movement produced by skeletal muscles that leads to energy expenditure. Exercise is a subset of physical activity that is structured, repetitive, and purposefully designed to improve or maintain one or more components of physical fitness.
There are various ways to categorize types of exercise. Commonly, and frequently mentioned in recommendations by medical associations, are classifications by intensity (light-moderate-high), by effect (endurance-strength), and by metabolic process (aerobic-anaerobic). Specific examples of exercises according to each classification are as follows:
- Light-intensity exercises: walking at less than 4.7 km/h (3 mph), light household chores, …
- Moderate-intensity exercises: walking at a moderate or brisk pace (4.1-6.5 km/h or 2.5-4 mph), slow cycling (15 km/h or 9 mph), painting/decorating, vacuuming, gardening (mowing the lawn), playing golf, playing doubles tennis, dancing, water aerobics, …
- High-intensity exercises: race walking, jogging, cycling at more than 15 km/h (9 mph), heavy gardening (continuous digging or hoeing), lap swimming, playing singles tennis, …
- Aerobic exercise, also known as endurance exercise, involves activities where the individual moves, breathes faster, and increases blood flow to the body’s organs, helping muscles obtain enough oxygen to generate the energy needed for the activity. This type of exercise can be sustained over a long period. A simple way to recognize aerobic exercise is that one can talk while exercising without gasping for breath. Examples include walking, jogging, aerobic workouts, swimming, cycling, playing badminton, playing volleyball, running on a treadmill, or stationary cycling in a gym, …
- Anaerobic exercise, also known as strength or power training, involves high-intensity activities that are not sustained, explosively releasing energy rapidly with maximal effort over a short period. It predominantly utilizes stored energy through anaerobic glycolysis. This type of exercise pushes the body to operate at its maximum capacity, where the muscle’s demand for oxygen exceeds the body’s energy supply, making it unsustainable for extended durations. Examples include sprinting and weightlifting, …
The effectiveness of exercise:
In terms of effectiveness, exercise can be broadly categorized into two main types: endurance training and resistance training.
Endurance training focuses on improving the ability to perform rhythmic exercises over extended periods, which helps prolong workout duration below maximum intensity while engaging specific muscles.
Resistance training aims to maximize muscle strength, enhancing overall muscular power.
The cardiovascular changes during exercise:
The circulatory system (including the heart and blood vessels): During exercise, muscle activity increases, requiring the body to supply more nutrients and oxygen to sustain performance. Therefore, the circulatory system enhances its activity to meet the body’s demands.
The cardiac muscle contraction strength and heart rate: Individuals who exercise regularly tend to have thicker and stronger cardiac muscles, resulting in a more powerful contraction of the heart and a lower resting heart rate. Conversely, individuals who exercise less may experience a faster heart rate during physical exertion, leading to quicker fatigue and increased likelihood of dizziness or fainting, …
The elasticity of blood vessels: Exercise increases the elasticity of blood vessels, helping to reduce the risk of stiff arteries associated with aging (a cause of high blood pressure).
Number of red blood cells and white blood cells: During exercise, the number of red blood cells and white blood cells in the blood increases. Red blood cells aid in oxygen and carbon dioxide transport and exchange, while white blood cells contribute to the body’s immune defense.
The benefits of exercise:
Exercise helps reduce the risk of all-cause mortality and decrease the risk of cardiovascular mortality in (1) healthy individuals, (2) those with risk factors for coronary artery disease, and (3) individuals already diagnosed with heart disease. This benefit is not only explained by biological mechanisms but has also been demonstrated in numerous studies.
- In terms of biological mechanisms, exercise positively impacts all risk factors (such as hypertension, lipid disorders, obesity, and type 2 diabetes), promoting physical health and enhancing mental well-being.
- Regarding research, long-term observational studies indicate that moderate physical activity (expending approximately 1000 kcal per week during leisure time) reduces the risk of cardiovascular mortality and all-cause mortality by 30-40% compared to inactive individuals.
How much exercise is sufficient to produce beneficial effects on cardiovascular health?
The basic principles of constructing exercise programs in sports and fitness generally rely on individual health status and training goals, personalized through four fundamental factors known by the acronym FITT: Frequency, Intensity, Time, and Type.
According to the recommendations of the Vietnam Cardiology Association for preventing cardiovascular diseases, exercise is advised as follows:
- To reduce the risk of all-cause mortality, incidence, and mortality from cardiovascular disease in adults of all ages, it is recommended to engage in at least 150-300 minutes of moderate-intensity exercise per week, or 75-150 minutes of vigorous-intensity exercise per week. If unable to meet these targets, individuals should maintain suitable physical activity according to their abilities and health conditions. It is advisable to reduce sedentary time and engage in at least one light-intensity activity per day.
- In addition to aerobic exercises, it is recommended to perform strength training exercises at least 2 days per week to reduce the risk of all-cause mortality.
When should screening for cardiovascular risk during exercise be considered?
Exercise is beneficial for patients with cardiovascular disease, but the risk associated with high-intensity training in these individuals can also increase, especially in those with undiagnosed heart conditions.
Screening and assessing risk before exercise, especially with vigorous-intensity activities, are crucial to prevent unfortunate events such as sudden cardiac arrest during workouts. However, the depth of screening may vary based on individual characteristics and initial stratification of cardiovascular risk. Recommendations for screening for cardiovascular event risk before exercise are as follows:
- Individuals with a habit of exercising and low to moderate cardiovascular risk can participate in all types of physical exercises.
- Those who exercise less and have high to very high cardiovascular risk can engage in low-intensity exercises without needing extensive cardiovascular health checks.
- Individuals who are less active and/or have high to very high cardiovascular risk should undergo thorough cardiovascular health checks if they wish to engage in moderate to high-intensity exercises.
Considerations for exercising in specific populations:
Middle-aged and older adults who are not accustomed to physical activity should engage in regular physical activity with gradually increasing intensity and duration (e.g., starting with 15-20 minutes of walking per day, increasing to 30-60 minutes per day over a few weeks, gradually incorporating jogging or running once they are comfortable).
Individuals known to have heart disease should warm up for at least 5 minutes before each exercise session and cool down gradually for at least 5 minutes afterward. This helps prevent sudden myocardial ischemia due to abrupt strenuous exertion and avoids post-exercise hypotension.
Those who are not accustomed to physical activity or have known heart disease should avoid exercising under adverse conditions such as extreme heat or cold, high humidity, or altitudes above 1500 meters.
Individuals with uncontrolled hypertension (systolic blood pressure > 160 mmHg) are not advised to engage in high-intensity exercise until their blood pressure is under control.
Those with well-controlled hypertension but high cardiovascular risk and/or target organ damage should avoid high-intensity resistance exercise.
Individuals with well-controlled hypertension, obesity, or diabetes should engage in resistance exercises at least 3 times per week, along with moderate to vigorous aerobic exercise (≥ 30 minutes per day, 5-7 days per week).
Tips to prevent injuries during exercise:
Respect your body’s limits: Choose suitable sports or exercises that match your physical condition and age.
Avoid being a ‘weekend warrior’: Distribute your workouts evenly throughout the week instead of pushing yourself excessively on weekends.
Use appropriate protective gear and equipment.
Listen to your body: If you feel tired or experience pain during exercise, rest and address any discomfort before it becomes serious.
Consult a specialist doctor promptly if any issues arise.
Specialist level 2 doctor. Nguyen Chi Thanh
References:
- Exercise and fitness in the prevention of atherosclerotic cardiovascular disease – UpToDate. Accessed: June 3, 2024.
- Decision No. 5333/QD-BYT dated December 23, 2020 of the Ministry of Health on the issuance of the professional document ‘Prevention of primary cardiovascular diseases.’
- Thượng Thanh Phương (2022), ‘Exercise and sports in the prevention of atherosclerotic cardiovascular disease,’ Journal of Cardiology, Ho Chi Minh City, electronically published on November 7, 2022 and November 22, 2022.
- Hồ Huỳnh Quang Trí (2016), ‘Sports and cardiovascular risk,’ electronic publication on the website of the Ho Chi Minh City Heart Institute on June 17, 2016.
- Special topic ‘Meaning, effects, and some common pathological conditions in physical training and sports’ published on the website of Thu Dau Mot University.
