The link between long-term high-volume exercise and coronary atherosclerosis is complex and remains unclear. Physical activity has cardiovascular benefits, yet studies have linked endurance training with a higher incidence of coronary atherosclerosis and plaque progression among athletes.

Leandro Slipczuk Bustamante, M.D., Ph.D., and colleagues at Albert Einstein College of Medicine and Montefiore have now conducted the first meta-analysis on the relationship between subclinical coronary atherosclerosis (i.e., not producing symptoms) and exercise volume.  The meta-analysis involved nine observational studies involving more than 61,000 participants: male and female high-volume-exercising athletes (>3,000 MET-min/week which could be reached by running at 6 mph for 45 min/day for 5–6 days or cycling at 16-19 mph for 40 min for 7 days), moderate-volume exercising athletes, and healthy nonathletes. All participants had undergone cardiac computer tomography to assess the extent of coronary artery calcification; the higher the calcium “score,” the greater the severity of coronary atherosclerosis. In addition, total calcified plaque number and plaque volume were assessed by coronary computed tomography angiography.

The study found that male athletes engaged in high-volume exercise had significantly higher calcium scores and total calcified plaque volumes compares with male nonathletes, while moderate-volume male exercisers had significantly lower plaque volumes than male nonathletes. For female participants, high-volume exercisers had a significantly lower number of calcified plaques per person than female nonathletes, and moderate-volume exercisers had significantly lower calcified plaque volumes than nonathletes. The results, published online on May 14 in JACC: Advances, suggest that athletes are not immune to coronary artery disease and that potential risks are associated with very high or extreme levels of exercise.

Dr. Slipczuk Bustamante is an associate professor of medicine at Einstein, section head of clinical cardiology, and director of the Advanced Cardiac Imaging Program and the Cardiovascular Atherosclerosis and Lipid Disorder Center at Montefiore.