ATLANTA — Lack of exercise may be as strongly linked to heart disease as are three better-known culprits: smoking, high blood pressure and high cholesterol, the national Centers for Disease Control said Thursday.
Prompted by a lack of solid findings in previous research on physical activity and heart disease, the CDC undertook a two-year analysis of 43 studies on the topic.
When suspected flaws in some of those studies were taken into account and removed, the CDC said, researchers were left with "a consistent statistically significant association" between a lack of exercise and coronary heart disease.
Rates Activity Levels
The CDC found that people at the lowest levels of physical activity had a risk of heart disease 1.9 times greater than those at the highest level. That risk is statistically similar to the increased risks for pack-a-day smokers, people with high blood pressure and those with elevated serum cholesterol levels.
"The results indicate that physical inactivity raises your risk of coronary heart disease," said Dr. Carl Caspersen, a researcher with the Atlanta-based CDC.
The problems found with previous studies included imprecise definitions of inactivity, Caspersen said. "When you improve the measurement of physical activity, you improve the ability to find a significant association" between lack of exercise and an increased risk of heart disease, he said.
CDC researchers said lack of exercise may be a much more serious problem than other risk factors for heart disease, because it is so much more widespread.
Fifty-nine percent of Americans exercise less than three 20-minute sessions a week, the CDC noted. By contrast, 18% smoke a pack of cigarettes each day, 10% have high cholesterol and 10% have uncontrolled high blood pressure.