By Gabe Sanders PhD, NSCA-CSCS
Many individuals believe that running is a great exercise and is healthy for your heart. Indeed, if you are healthy enough to engage in some light jogging/ running combined with a smart running regimen, you can improve your body composition and cardiovascular system. However, excessive running may be a different story.
What is excessive running?
You may be asking yourself “What is excessive running?” and “How many miles per run is considered excessive?” The answer is quite complex and can have many different answers. Training for a half marathon/ marathon could be considered excessive for most people. Some people have a lifelong goal to run a half marathon (13.1 miles) or maybe even a full marathon (26.2 miles). While finishing either of these long distance runs can be quite an achievement, training for a long distance race is not easy. Training and preparing your body to run all those miles can be a daunting task. The effect long distance running can have on your body may surprise you.
Running a marathon may break down heart muscle tissue
Training for a long distance event like a 10k, half, or full marathon requires an individual to run many miles leading up to the race. The mileage necessary for proper training can range from 15 miles per week to as many as 100 miles per week, for elite runners. The more miles you run, the more your heart has to work to supply your muscles with oxygenated, nutrient-rich blood. Researchers have found that running a marathon may break down the heart muscle tissue in a negative way.
There are biomarkers found in your blood. One of these biomarkers is called cardiac troponin I. A high level of this biomarker is indicative of cardiac tissue injury and is found in elevated levels after a person experiences a heart attack. Research has found that your cardiac troponin I levels can increase by as much as 571% compared to your resting levels after running a marathon!
Even more alarming, the increase in cardiac troponin I from running a marathon is 135% greater than the levels found in people who recently suffered a heart attack. Running marathons places a lot of stress on your heart, and for most people, running/ jogging at lower intensities for shorter distances would be a healthier alternative and place less stress on your joints and heart.
Walking at a moderate intensity or approximately 2.5 to 3.0 miles per hour on a treadmill can improve your blood pressure, cholesterol, and significantly reduce your risk of developing heart disease. For those simply looking to be healthy, walking at a moderate intensity could be a better option than running!
Article’s Resources
Eijsvogels TM, Hoogerwerf MD, Maessen MF, Seeger JP, George KP, Hopman MT, Thijssen DJ. Predictors of cardiac troponin release after a marathon. Journal of Science and Medicine in Sport. 2015. 18:88-92.
The American Heart Association. Walk, don’t run, your way to a healthy heart.