Are Marathons Bad for your Heart?

Marathons are excellent tests of physical and mental endurance, and many people (rightly) see completing their first marathon as an exciting milestone. 

However, before you go and sign up for your next 26.2K, you should know that there has been some debate amongst the running and medical communities regarding the impact of long-distance running on cardiovascular health.

While many experts contend that running is beneficial for heart health, there are others who suggest that running long distances regularly may increase the production of atherosclerotic plaque in the coronary arteries alongside other cardiovascular issues. 

So, are marathons really bad for your heart? Stick around to find out!

Does Marathon Running Damage the Heart?

For a long time, the medical consensus on the health impacts of running marathons has been positive. 

Indeed, there are several areas in which marathon running could benefit your heart health. 

For one thing, running has been proven to lower blood pressure and ‘bad’ cholesterol levels in the long term. Healthy blood pressure and cholesterol are essential for good heart health. 

Running has also been shown to strengthen the heart muscle over time. As a result of the heart growing stronger, runners’ hearts often work more efficiently than those of sedentary individuals. 

Moreover, because marathon running is linked to weight loss, it also helps to reduce the chances of heart attack or heart failure due to fatty buildups in the arteries. 

Running also correlates with a decreased risk of heart disease and blood clots in the heart. 

However, recent studies on the amount of plaque in the hearts of runners versus non-runners have caused some panic, demonstrating that active individuals are more prone to coronary artery calcification. 

This might sound frightening, but it’s important to remember that not all plaque found in the heart is necessarily bad.

A Dutch study on the subject revealed that while calcification does increase in runners, the plaque is usually less harmful (benign) compared to the fatty plaque found in the hearts of non-active people. 

So, while it’s clear that marathon running does have an impact on plaque composition in the heart, the evidence does not suggest that these changes are necessarily dangerous. 

Do Marathon Runners Have Enlarged Hearts?

Another theory that has recently been put forward by researchers is that long-distance and marathon runners may suffer from an enlargement of the heart muscle. 

This claim is based on scientific research showing that marathon running can thicken the left ventricle of the heart over time. 

Again, this sounds very alarming because cardiovascular enlargement (cardiomegaly) is usually associated with underlying health conditions. 

However, the supporting evidence for this research also shows that, in marathon runners, ventricle thickening isn’t necessarily harmful.

Marathon runners develop enlarged hearts because the heart muscle has been built up through intense exercise, as opposed to the ventricular weakening usually associated with cardiomegaly in non-runners. 

With that being said, a study conducted in 2012 showed that up to 25% of runners may experience dilation of the right ventricle and atrium immediately after running.

Dr. Peter McCullough, head cardiovascular researcher at the Dallas Baylor Heart and Vascular Insitute, has theorized that this could lead to myocardial fibrosis (scarring of the heart) in about 1% of people. 

On the other hand, a 2008 study at Standford University showed a higher incidence of death in non-runners over 50 than runners in the same age group. 

The culmination of this research certainly indicates that more investigation into the links between running and heart health should be carried out.

However, what we can conclude from the available data is that, while running definitely impacts the structure and size of the heart, life expectancy and overall health does not seem to suffer in most cases. 

Do Runners Have More Heart Attacks?

Studies have conclusively shown that intense exercise temporarily elevates the risk of myocardial infarction, more commonly known as a heart attack. 

Individuals most at risk of a heart attack from long-distance running are new runners (those whose hearts have not yet been strengthened by the exercise), runners who are overweight, and runners with a family history of heart problems. 

However, it’s important to remember that this applies to all forms of high-intensity exercise, not just marathon running.

Moreover, the likelihood of suddenly dying from a heart attack in the middle of a marathon is very low compared to the heart problems associated with a sedentary, unhealthy lifestyle. 

If you’re planning on training for your very first marathon or are considering pushing yourself to run faster or longer than you have before, it’s a good idea to have your heart checked out by a doctor beforehand.

This is especially important if you have a history of heart problems in your family or if you’ve ever experienced symptoms such as heart palpitations or high blood pressure. 

Additionally, it’s vitally important to listen to the cues your body is giving out. If you’re running and start to experience chest pain, sudden and severe shortness of breath, lightheadedness, or pain or numbness in your limbs, stop straight away and seek urgent medical assistance. No personal best is worth sacrificing your heart over. 

Can I Run a Marathon After a Heart Attack?

While we certainly wouldn’t recommend plunging straight back into running full marathons immediately after a heart attack, you shouldn’t be afraid to start exercising again. 

The important thing is to follow your doctor’s advice and take it slow. Start by building up your exercise through gentle walks. Once you have the all-clear from your physician, you can start moderate-intensity exercise again. 

Eventually, if you maintain a healthy diet and don’t overdo it during your recovery, there’s every chance you’ll be able to get back into marathon running, as many heart attack survivors have done. Just remember to be patient and check in with your doctor every step of the way. 

Final Thoughts

An analysis of the available research and data surrounding the impact of running on cardiovascular health suggests that, overall, marathon running is more likely to be beneficial to your heart than detrimental. 

However, you should definitely get the all-clear from your doctor before running a marathon if you have a family history of cardiovascular issues or have experienced heart-related symptoms in the past. 

Ultimately, the key to heart-healthy marathon running is to listen to your body’s limits and avoid pushing yourself too hard.