Time for our Workout Of The Month. Each month we take a look at a different exercise and break it down by movement, how to do it, and discuss some of the positive versus negative impact that it can have to you and your level of fitness. Some workout’s of the month breakdown how to do a common exercise, others feature a specific workout. This month I’ll be taking a look at a recent study that suggested excess exercise could cause coronary artery calcification.

Does Excess Exercise Cause Artery Calcification?

A recent study that spanned twenty-five years came out following people and looked specifically for artery calcification. The results came back showing that those who exercised longer than the national physical activity guidelines were more likely to develop coronary artery calcification. Calcifications within the arteries are a result of years of plaque buildup within the important arteries of the heart that after time, become calcified. There is a large correlation between calcified arteries and heart disease.

Who The Study Tested

The study looked at 3,175 participants that were recruited between March 1985 and June 1986. The group consisted of both white and black men and women between the ages of 18 and 30. The individuals were followed for 25 years up until 2011.  The participants of the study were split into three groups based off exercise levels:

  • Group one: people who exercised for under 150 minutes per week (below national guidelines).
  • Group two: participants who met physical activity guidelines by exercising 150 minutes per week.
  • Group three: participants who exceeded the national activity guidelines by exercising for over 450 minutes per week.

Between the three groups, coronary artery calcification was determined by using CT scans of the chest.  Calficications in the coronary arteries were tested in the final year of the study when the participants were between the ages of 43 and 55.

What The Study Found

The major findings of the study were that those participants who had the highest levels of physical activity were 27 percent more likely to develop calcifications in the coronary arteries than those who exercised for under 150 hours a week. When the study was broken down by white and black and males and females, white men were 86 percent more likely to have coronary artery calcifications. Black men and both black and white women were not significantly at risk for what the study considered excess exercise.

Problems With The Study

While the media could potentially use this study to broadcast headlines to suggest that too much exercise may be a bad thing, this study should not deter you from exercising more than 450 hours a week, or keep you exercising at all.  Here’s why:

  • CT scans that detect these calcifications only show that calcificcations are present, not how much an artery is actually blocked.
  • The study doesn’t specify or test for types of cholesterol that had potentially caused the calcifications.  There are more stable types of plaque which are less likely to rupture and cause a heart attack.
  • The study only followed people who exercised specific amounts of time but didn’t differentiate between types of exercise that were performed between the people.
  • There are other factors that can contribute to plaque buildup: stress, drugs, alcohol, smoking, genetics, sleep, etc.
  • Nutrition wasn’t taken into account.

Does Excess Exercise Really Cause Coronary Artery Calcification?

According to this study, it could. But there are so many other factors that need to be taken into consideration before a true conclusion is reached. The theory is that excess exercise could possibly lead to too much stress placed on the body which could cause artery calcification. The bottom line is this: listen to your body, get enough sleep, and maintain healthy lifestyle habits when it comes to nutrition and minimizing unhealthy stress.  White men most at risk

Sources:

Laddu R., Deepika PhD., et. al. “25-Year Physical Activity Trajectories and Development Of Subclinical Coronary Artery Disease as Measured By Coronary Calcium: The Coronary Artery Risk Development In Young Adults (CARDIA) Study.” Mayo Clinic Proceedings. November 2017. Web. 9 November 2017.