Engaging in moderate physical activity is one of the most beneficial actions one can take for heart health. Exercising at a moderate intensity—wherein the heart rate increases but breathlessness is not experienced—for a duration of 30 to 45 minutes on five days of the week can significantly diminish the risk of heart disease. Increasing the frequency and duration of exercise, or occasionally participating in high-intensity workouts that inhibit the ability to converse comfortably, can yield even greater health benefits.
Nevertheless, there are circumstances in which physical activity may transition from being advantageous to detrimental for heart health.
Potential Cardiac Issues Associated with Sports Participation
While physical activity is generally beneficial for cardiovascular health, intense exercise can, in certain instances, lead to the following conditions:
- Atrial Fibrillation
Atrial fibrillation is characterized by disorganized electrical activity that disrupts the normal sinus rhythm of the heart. This condition impairs the myocardium’s ability to contract effectively, thereby compromising blood supply to the body and increasing the risk of stroke and heart failure. Atrial fibrillation is one of the most prevalent rhythm disorders observed in athletes and can arise from various factors, including heightened parasympathetic nervous system tone, electrolyte imbalances due to dehydration during prolonged training or competition, and exercising while experiencing acute respiratory infections. Additionally, gastroesophageal reflux—where stomach contents flow back into the esophagus—can also trigger atrial fibrillation, particularly when an athlete overeats or consumes excessive protein prior to exercise. This condition can lead to esophageal inflammation, which subsequently stimulates the autonomic nervous system and affects cardiac function. A study involving nearly 17,000 participants revealed that men who engaged in high-intensity running five to seven times per week exhibited a 50% increased risk of developing atrial fibrillation compared to those who exercised less frequently. Furthermore, three meta-analyses indicated that endurance athletes face a risk of atrial fibrillation that is 2 to 10 times greater than that of non-endurance athletes. - Atherosclerosis of the Coronary Arteries
Atherosclerosis involves the accumulation of fatty or calcium plaques within the arteries that supply blood to the heart. In athletes, the narrowing of these arteries is often attributed to stable calcified plaques. Research has shown that older male marathon runners exhibit higher rates of coronary artery calcification compared to non-runners. Conversely, studies suggest that female runners do not demonstrate an increased risk; some studies even indicate that female runners may have less calcified plaque than their non-running counterparts. Several hypotheses exist regarding the mechanisms by which exercise may contribute to atherosclerosis, including alterations in calcium and vitamin D metabolism, increased levels of hormones that promote arterial calcification, and mechanical stress on coronary artery walls. - Sudden Cardiac Death During Physical Activity
Sudden cardiac death can occur during training or competition due to underlying conditions such as coronary artery disease, arrhythmias (particularly ventricular tachycardia and fibrillation), structural heart disease, and myocarditis (inflammation of the heart muscle). The causes of sudden cardiac death can vary by age: individuals over 35 are more likely to succumb to atherosclerotic diseases, while younger athletes may be at risk due to congenital heart abnormalities, cardiomyopathy, or myocarditis.
Individuals with diagnosed or latent heart conditions who are unaccustomed to physical activity and subsequently engage in high-intensity exercise (exceeding 60% of their capacity) are particularly vulnerable.
Identifying Potentially Hazardous Sports for Cardiac Health
The impact of sports on heart health is contingent upon the intensity and duration of the activity. Moderate intensity is defined as exerting 45–59% of one’s maximum effort, while high intensity is classified as exerting 60% or more. While some sports are inherently high-intensity, others are low-intensity, with the latter being less common. Low-intensity sports include golf, bowling, billiards, and table tennis. Team sports may also vary in intensity depending on the nature and level of play.
Most competitive sports are categorized as high-intensity due to the physical exertion and psychological stress involved, which can elevate heart rates and increase cardiac strain. High-intensity sports encompass contact activities and extreme sports such as open-water kayaking, freestyle skiing, cross-country cycling, and downhill skiing. The inherent risks associated with these activities can lead to elevated heart rates, even if the physical demands are not excessively strenuous.
Strategies for Protecting Cardiac Health During Exercise
It is imperative to ascertain whether one is fit to exercise and to determine the appropriate intensity level. The American Heart Association provides the following recommendations:
- Individuals who are physically active, possess normal metabolic function, and exhibit no symptoms of heart, vascular, or kidney disease may engage in moderate to vigorous exercise, gradually increasing the intensity. Those exhibiting signs of health issues should cease activity and consult a physician.
- Individuals with heart disease but no symptoms, who have consulted a physician within the past year and received clearance to exercise, may engage in moderate-intensity activities, provided no abnormal symptoms arise during exercise. Should such symptoms occur, they should discontinue activity and seek medical advice.
- Physically inactive individuals with heart disease may initiate light to moderate-intensity exercise without medical supervision, provided they do not experience symptoms.
- Inactive individuals with heart disease or symptoms should consult a physician prior to commencing any exercise regimen, regardless of the intended intensity.
Additionally, it is advisable to undergo an annual health check-up. For those participating in competitive sports, such evaluations are typically required for clearance.
Moreover, it is crucial to mitigate risk factors, including:
- Inadequate Sleep: Insufficient sleep (less than six hours per night) can elevate blood pressure and increase the risk of heart disease. Therefore, individuals who are sleep-deprived should refrain from engaging in strenuous, high-intensity workouts.
- Exercising While Ill: A rise in body temperature correlates with an increase in heart rate; thus, exercising with a fever can lead to excessive heart strain. Mild cold symptoms “above the neck” (e.g., stuffy nose, sore throat) may permit continued exercise, but if body temperature rises at rest, exercise should be postponed until recovery.
- Psychological Stress: Psychological stress can adversely affect cardiovascular health; therefore, during challenging life periods, it is prudent to carefully select exercise intensity.
- Inadequate Nutrition: Prolonged, intense workouts can deplete glycogen reserves in muscles and the liver. Insufficient carbohydrate intake may lead to hypoglycemia during or after exercise, a condition that, while primarily studied in individuals with diabetes, could also pose risks to healthy individuals if it occurs frequently.
It is noteworthy that while professional and semi-professional athletes may train similarly, elite athletes typically receive continuous oversight from coaches and medical professionals, whereas amateurs may not. Regular evaluations, including annual electrocardiograms (ECGs) and consultations with sports physicians or cardiologists, can help mitigate potential adverse effects. At least once a year, individuals should take the opportunity to discuss their health status with a physician during routine check-ups.
