Study shows that extreme exercise does not increase risk of death from heart disease

DALLAS, Jan. 30, 2019 (GLOBE NEWSWIRE) — Athletes come in all forms, from the professional athlete to the everyday runner. We know regular exercise is good for us, but there has been a lingering question about how much is too much. When it comes to the heart, can too much exercise actually be dangerous?

Researchers from The Cooper Institute and UT Southwestern Medical Center collaborated on a study, now published in JAMA Cardiology, to find out if too much exercise increases the risk of heart disease and death in highly active individuals with early hardening of the arteries. The study found that there was no additional risk of heart disease death even in this group.

“The current study shows no increased risk of mortality in high-volume, high-intensity athletes who have coronary artery calcium,” said Dr. Laura DeFina, CEO and Chief Science Officer for The Cooper Institute. “Certainly, these highly active people should review their cardiovascular disease risk with their primary care doctor or cardiologists, but there is no reason to think they can’t continue exercising at high levels.”

Coronary artery calcification (CAC) is a footprint of atherosclerosis, a disease in which plaque builds up in the arteries and gives rise to heart attack and stroke. While the majority of the highly active people in the study had low levels of coronary calcium, their risk of having CAC was 11 percent greater than those who exercised less frequently. Importantly, investigators also determined that higher calcium levels did not raise their risk for cardiovascular or all-cause mortality.

“The question has never been whether exercise is good for you, but whether extreme exercise is bad for you. For the past decade or so, there’s been increasing concern that high-volume, high-intensity exercise could injure the heart. We found that high volumes of exercise are safe, even when coronary calcium levels are high,” said Dr. Benjamin Levine from UT Southwestern Medical Center. Dr. Levine is a Professor of Internal Medicine and Director of the Institute for Exercise and Environmental Medicine, a collaboration between UT Southwestern and Texas Health Presbyterian Hospital Dallas.

Researchers from The Cooper Institute and UT Southwestern studied data from the Cooper Center Longitudinal Study. A total of 21,758 generally healthy men ages 40 to 80 and without cardiovascular disease were followed for mortality between 1998 and 2013. The athletes, a majority of them in middle age, reported their physical activity levels and underwent coronary calcium scanning. Most were predominantly runners, but some were cyclists, swimmers, or rowers. A subgroup of athletes even trained in three of these sports. Women were not included in the study because they have lower mortality rates than men.

“The known benefits of regular physical activity in the general population include decreased mortality, heart disease, diabetes, and many other medical conditions which reminds us how important it is participate in regular physical activity as recommended by the 2018 Physical Activity Guidelines,” said Dr. Laura DeFina, Chief Science Officer of The Cooper Institute and first author of the study.

The updated Physical Activity Guidelines for Americans recommends 150-300 minutes per week of moderate-intensity aerobic physical activity or 75-150 minutes per week of vigorous intensity. High-volume, high-intensity exercise was defined in this study as at least five to six hours per week at a pace of 10 minutes per mile. The average amount of high-intensity exercise in this group was eight hours per week.

“The takeaway from this study is that it safe to exercise at high levels, even if you have a little more coronary calcium,” said Dr. DeFina. “Exercise is still the best preventive medicine.”

Established in 1970, The Cooper Institute is a nonprofit dedicated to promoting life-long health and wellness worldwide through research and education. Founded by Kenneth H. Cooper, MD, MPH, The Cooper Institute translates the latest scientific findings into proactive solutions that improve population health. Key areas of focus are research, adult education, and youth programs. Through these initiatives, The Cooper Institute helps people lead better, longer lives now and Well. Into the Future. To learn more, visit
Owned and operated by The Cooper Institute, the Cooper Center Longitudinal Study (CCLS) is the largest and longest-running open research study in the world with measured fitness. Developed in 1970, it contains over 300,000 patient records from the Cooper Clinic and is one of the world’s most extensive studies relating fitness to overall wellbeing and the improvement of public health. To learn more, visit

UT Southwestern, one of the premier academic medical centers in the nation, integrates pioneering biomedical research with exceptional clinical care and education. The institution’s faculty has received six Nobel Prizes, and includes 22 members of the National Academy of Sciences, 17 members of the National Academy of Medicine, and 15 Howard Hughes Medical Institute Investigators. The faculty of more than 2,700 is responsible for groundbreaking medical advances and is committed to translating science-driven research quickly to new clinical treatments. UT Southwestern physicians provide care in about 80 specialties to more than 105,000 hospitalized patients, nearly 370,000 emergency room cases, and oversee approximately 2.4 million outpatient visits a year. To learn more, visit