- According to data presented at a recent American Heart Association conference, exercising at extreme, high-volumes won’t increase your risk for heart disease.
- Working out benefits your coronary arteries, lowers your risk of having an irregular heart beat, and improves the ability of the arteries and blood vessels to dilate—which all leads to more efficient heart function.
When it comes to heart health, is there a point where too much exercise is, well, too much? New data presented at a recent American Heart Association conference suggests there really isn’t an upper limit, even among those who exercise for hours each day.
Researchers looked at 2,154 athletes—men and women with an average age of 52—who were free of cardiovascular disease and split them into two groups: either a high volume of 3,000 to 10,000 MET minutes per week or an extraordinary volume of over 10,000 MET minutes weekly.
MET stands for “metabolic equivalent” and is a way of comparing energy expenditure during activity. For example, 1,000 MET minutes per week is roughly equivalent to running 10 miles a week at a pace of 10 minutes per mile.
Looking at 10 years of data, the researchers found that none of the extraordinary-volume athletes showed higher cardiovascular disease risk compared to the high volume group, even though both groups did have increased coronary artery calcium (CAC). Calcium in your arteries is bad because it can mean there’s a buildup of plaque, which can increase your risk of heart attack or stroke, according to the American College of Cardiology.
Led by the Cooper Institute in Dallas and cardiologist Benjamin Levine, M.D., at the University of Texas Southwestern Medical Center, this study is something of a followup to research presented earlier this year, which looked at physical activity and CAC of nearly 22,000 healthy men over a 15-year time period. The participants ranged in age between 40 to 80, and most were runners—but cyclists, rowers, and swimmers were also represented.
In that study, researchers found elevated levels of CAC were more prevalent among those with higher activity levels, but not in a way that seemed either significant or raised cardiovascular disease risk, Levine told Runner’s World. At the end of the study timeframe, participants didn’t show an increased risk of mortality compared to those without activity-related CAC.
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The presence of high CAC levels is often used to diagnose atherosclerosis—a condition of the arteries characterized by hardening, which can restrict the blood flow to your organs and tissues—which is why it’s become a concern for those who exercise, Levine said. Both studies, he said, suggest that regular exercise—even at high volumes—should not be problematic for those looking to protect their heart health.
That’s because during exercise, calcium might increase—but so do parathyroid hormone levels, which modulates how calcium is deposited in the bloodstream, Levine said.
“Keep in mind, too, that when people are exercising, the movement provides benefits to the coronary arteries, making them more pliable,” he said. “You also lower arrhythmia [irregular heart beat] risk in general and improve the ability of the arteries and blood vessels to dilate. All of this leads to more efficient heart function, even in the presence of increased coronary calcium.”
With all this said, if you have a history of heart disease in your family or have experienced heart issues in the past, always check with your physician before starting or increasing an exercise routine. If not, enjoy those long workouts without worry of hindering your heart health.