Some research has shown that ultra-fit athletes such as marathon runners can have cardiac damage such as heart scarring or arrhythmia, raising the question of whether too much aerobic exercise can be a bad thing.
In a new study, researchers found that while some ultra-athletes showed some minor calcium buildup in their coronary arteries, they were still healthier overall than a control group of people who only got moderate exercise.
The research was conducted by a team at Colorado State University.
In the study, they examined 25 ultra-athletes in Colorado. They also tested 18 Coloradans who were moderately active.
The ultra-athletes were healthy individuals between the ages of 40 and 65 who had been training and competing for at least 10 years in events like ultra-marathons and triathlons.
The control group consisted of healthy people in the same age group who were getting at least 150 minutes of exercise per week.
Both groups underwent a rigorous screening process to ensure that none of them had other health factors that might affect the results, such as obesity, high cholesterol or hypertension.
The team did vascular tests on the people in the lab, having them do an aerobic fitness test and assessing elements such as the stiffness of their carotid arteries and the dilation of vessels in their arms, for instance.
Then the subjects were sent for echocardiograms of their heart structure/function as well as imaging of their coronary artery calcium levels. The participants also underwent cardiac fibrosis tests.
By most measures, such as stiffness of the aorta and the elasticity and thickness of the carotid artery, the ultra-athletes had better cardiovascular health than the control group, and none of the subjects had any scarring on their hearts.
But eight of the ultra-athletes had calcium deposits in their arteries, while only two in the control group had such deposits.
Even though a higher percentage of the ultra-athletes had calcium deposits, their overall cardiovascular health was still better than those in the control group.
The team concluded that extreme amounts of cardio are not deleterious to one’s health.
When other risk factors such as blood pressure, cholesterol and age were used along with the calcium score to determine heart disease risk, most of the athletes were below the threshold for statin treatment.
Generally, the team didn’t find evidence that would make them recommend that people not exercise too much. The overall benefits of exercise outweigh anything.
The researchers added, however, that some people may have other health factors, such as a family history of heart disease, that they should discuss with their doctor before becoming ultra-athletes.
One author of the study is Frank Dinenno, a professor in the Department of Health and Exercise Science.