Regular physical activity offers a wide range of health benefits, including protection against the development of heart disease. But in rare cases, it appears to have the opposite effect:
Exercise-related acute cardiovascular events—and sudden cardiac deaths—have been reported in the medical literature and the lay press. In some people with underlying heart disease, exercise-related increases in heart rate and blood pressure can cause coronary plaque rupture, thrombosis, and lethal heart rhythm irregularities. The cause of exercise-related cardiovascular events largely depends on the exerciser’s age. Coronary artery disease is the most frequent autopsy finding in individuals over the age of 40. In contrast, inherited structural cardiovascular abnormalities are a major cause of fatal heart rhythms during strenuous physical activity in younger athletes.
Risk in perspective
The incidence of cardiovascular events during light- to moderate-intensity activities is extremely low and similar to that expected at rest. Unaccustomed vigorous physical exertion, however, especially in people with underlying heart disease, appears to transiently increase the risk of acute cardiac events. Activities such as competitive squash/racquetball, basketball, cross-country skiing, water skiing, heavy weight-lifting, and high-intensity interval training may place undue stress on the heart and are not recommended for people with known or suspected heart disease. Arm work, straining, breath-holding, and exposure to cold and wind appear to heighten the risk of acute cardiac events as well.
There are several steps you can take to reduce your risk of experiencing a cardiovascular event when exercising.
- If you are currently inactive, always start with a walking program. An initial goal is to walk at a speed of at least 3 miles per hour on a level surface, without symptoms.
- Warm up and cool down. The best warm-up for any activity is performing that activity at a lower intensity.
- Reduce the intensity of exercise in hot, humid weather and when working at high altitudes.
- Don’t ignore symptoms such as chest pain, dizziness, lightheadedness, heart palpitations (fast, slow, or irregular heartbeats), unusual fatigue, or shortness of breath. Many people who have experienced exercise-related cardiovascular complications had these symptoms in the days or weeks before the event. If you experience any of these symptoms while exercising or have pain or discomfort from your belly button up, stop exercise immediately and consult with your physician. Medical clearance is required before resuming your exercise regimen.
- Exercise regularly. The likelihood of cardiac events appears to be reduced by up to 50 percent in regular exercisers. For people who gradually progress to vigorous exercise, the more frequently vigorous exercise is performed, the lower the cardiac risk of each exercise bout. In other words, don’t cram your vigorous exercise into just one or two bouts per week. When it comes to extremely strenuous exercise, being a “weekend warrior” (or even less frequently) can be hazardous to your health.