Less Strenuous Exercise & Healthy Hearts | Heart Healthy Exercise Blog

Date: 06/30/2012    Written by: Beth Levine

An Overdose of Exercise

"Never go to excess, but let moderation be your guide." --Marcus Tullius Cicero

You try to be good every day, making time for a workout.  Whether you go to the gym, head outdoors, or exercise at home, you may still wonder if you are doing enough.  After all, look at your neighbor who goes into intense training for months at a time to prepare for running a full marathon.  That level of strenuous exercise can sometimes make you feel like your 20-minute jog and weight training circuit are child's play.

But those with less extreme exercise habits can now take heart (literally and figuratively). New research that took place at the Mid America Heart Institute of St. Luke's Hospital in Kansas City, Missouri, found that those who work out in smaller, less strenuous exercise doses may be more likely to have healthy hearts in comparison to their counterparts who go all out participating in endurance athletics.1  Such strenuous exercise on a regular basis may lower your body fat and strengthen your muscles, but your cardiovascular system benefits more from less exhaustive types of workouts.

The scientists analyzed both the physical structure of the heart muscle as well as levels of cardiac biomarkers in endurance athletes versus typical exercisers.  They discovered that 12 percent of the approximately 100 marathon-running elite athletes who participated had a scarring or thickening of their cardiac tissue, which can raise the risk of developing an atrial or ventricular arrhythmia.  Arrhythmias are potentially dangerous abnormal heart rhythms that affect the efficiency of the heart.2  That means the marathon runners face three times the arrhythmia risk of those who do not run in marathons.  The endurance athletes were also more likely to have calcium deposits on their artery walls, a risk factor for developing a narrowing of the arteries.

This would seem to corroborate research from last month that found that exercise can actually be harmful to a segment of the population.  That study, which took place at the Pennington Biomedical Research Center of Louisiana State University in Baton Rouge, compared the findings from six different trials with a total of 1,687 volunteers.3  The results appeared to show that for approximately 10 percent of the participants, exercise caused a dip in their cardiovascular health rather than an improvement.  The areas that were negatively affected in this population segment were blood pressure, insulin level, HDL cholesterol, or triglycerides.  In seven percent of the volunteers, more than one of these categories was impacted for the worse.

But none of this means it's time to throw away your running shoes and start living a life of sloth. Physical activity is essential to your health, and studies have shown that those who regularly work out live an average of five to seven years longer than those who do not.4  It's just a matter of using exercise to your advantage and not overdoing anything.  If you love running, by all means don't give it up.  But instead of pushing yourself to run for 15 miles, do a four-mile run instead.  Opt for interval training if you want to add intensity to your workout; these bursts can improve your fitness level without damaging the heart the way continuously taxing workouts may.  Then mix it up and incorporate strength training and flexibility exercises into your routine as well.  Strive for balance and don't focus on only one of these areas of fitness.  They are all equally important and very beneficial to your body.  A combination of cardiovascular activity, strength training, weight bearing exercise, stretching, resistance breathing, and balance-building routines will cover all of your fitness needs and help you reach and maintain your optimum health for the long term.


1 Eldred, Sheila. "Can You Exercise Too Much?" Discovery. 4 June 2012. Accessed 21 June 2012. <http://news.discovery.com/human/blog-can-you-exercise-too-much-120604.html>.

2 "Arrhythmias." Children's Hospital of Wisconsin. Accessed 22 June 2012. <http://www.chw.org/display/PPF/DocID/23082/router.asp>.

3 Kolata, Gina. "For Some, Exercise May Increase Heart Risk." New York Times. 30 May 2012. Accessed 22 June 2012. <http://well.blogs.nytimes.com/2012/05/30/can-exercise-be-bad-for-you/?ref=health>.

4 Langreth, Robert. "How To Live To 100." Forbes. 7 April 2009. Accessed 22 June 2012. <http://www.forbes.com/2009/04/06/centenarians-exercise-diet-personal-finance-retirement-live-to-100.html>.

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    Submitted by jlalanne on
    July 24, 2012 - 8:03am

    The studies found that 10 or 12 % of endurance runners had heart deposits. That percentage means nothing in terms of cause and effect.

    Submitted by Felix on
    September 5, 2013 - 9:01am

    What I am about to write has a connection with the title of your article "An overdose of excercise". and also it helped me to understand why this lady who was an elite athlete (she is on her 40's now) developed all the problems that you mentioned in your article, such as "arrhythmia and The endurance athletes were also more likely to have calcium deposits on their artery walls, a risk factor for developing a narrowing of the arteries" She developed calcium deposits on her artery walls. Could you please write and article explaining the mechanism how this endurance athletes are more proned to have calcium deposits than people who practice moderate type of excercise. In my case , I exercise every day but in moderation but some of my neighbors do not. I always thought that extreme excercise was not healthy but I have never came across data to back it up.
    thank you very much for your article

    Submitted by Deann Ohler on
    September 10, 2013 - 1:05pm

    Jon, I think you're really reaching in your conclusions here. First of all,12% of people in the first study mentioned have some cardiac scarring. Do they know if it's from the exercise, or if it was there previous to the extreme exercise? Extrapolating this to potential arrhymias, then making the statement that marathon runners have 3xs the risk is not scientific. The next study shows a decrease in cardiac health in either 10% or 7% of participants. This says exercise, period, not extreme exercise. So do you suggest we all stop all exercise? This doesn't fit into your title suggestion.
    In your final paragraph you suggest not running 15 miles but 4 miles - a pretty extreme drop! Who's to say running 4 miles would not be an overdose of exercise for some, while running 15 miles is not fairly easy for others?
    I absolutely agree that the best thing for health is balance - endurance, strength, and flexibility. But I would rather have seen an article based on that. And, why put limitations on our individual abilities? Better to figure those abilities out and proceed with a thoughtful program.

    Submitted by BaselineFoundation on
    September 11, 2013 - 7:05pm


    It appears you misread several aspects of the blog. The article was written by Foundation researcher, Beth Levine.  So, the conclusions you refer to were not hers, but of the researchers involved in the original studies as cited. Lastly, you refer to the study’s methodology as unscientific.  In the cited references, note that both studies are peer reviewed and published in the journal Mayo Clinic Proceedings and the journal PLoS One, respectively. 

    However, that said, it does not mean that the studies’ conclusions are automatically correct. But with two studies being published within a week of each other independently pointing in the same direction, they are certainly worth considering and not dismissing out of hand.

    Also note this is one article about a study.  We have many other articles on our site that discuss various aspects of exercise--if you are looking for other topics and overall recommendations.  Just do a search in the seach field at the top of every page.

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