Cardiac Risks in Long Distance Runners: How Running Long Distances Can Affect Your Heart

Running long distances is often seen as the epitome of physical fitness. From marathons to ultramarathons, endurance athletes are celebrated for their stamina, discipline, and cardiovascular health. However, emerging research and clinical cases reveal a more nuanced picture – long-term endurance exercise, especially at extreme levels, may come with potential cardiac risks.

Here, we’ll explore the various cardiac risks associated with long-distance running, highlight the symptoms to watch for, and discuss how monitoring long-term ECG with tools like the FDA cleared Frontier X Plus and wellness-based Frontier X2 can play a pivotal role in early detection and prevention.

Understanding the Athletic Heart vs. a Compromised Heart

Long-distance running induces structural and functional changes in the heart. Often referred to as “athlete’s heart,” these adaptations include a slower resting heart rate, enlarged cardiac chambers, and increased stroke volume. These changes are usually benign.

But how do you differentiate healthy heart adaptations from pathological changes that could lead to serious heart conditions?

Common Misconception:

A low resting heart rate and enlarged heart on imaging aren’t always safe. In some cases, they may mask or resemble signs of underlying cardiac disease.

Cardiac Risks in Long Distance Runners

1. Atrial Fibrillation (AFib)

One of the most well-documented conditions among endurance athletes is atrial fibrillation, a type of irregular heart rhythm. Studies suggest that long-distance runners are at an increased risk of AFib due to chronic volume overload and atrial stretching.

Warning Signs:

• Palpitations
• Dizziness or fainting
• Fatigue despite regular training
• Irregular pulse

2. Myocardial Fibrosis

Chronic extreme endurance exercise has been associated with scarring of the heart muscle, particularly the right ventricle. Over time, this can lead to arrhythmias and even heart failure. Myocardial fibrosis often goes undetected in routine cardiac screenings.

3. Right Ventricular Dysfunction

Unlike strength training, long-distance running places significant load on the right ventricle. Repeated stress can result in transient or even permanent dysfunction, which increases the risk of ventricular tachycardia and other dangerous arrhythmias.

4. Coronary Artery Calcification (CAC)

Surprisingly, even in athletes with a low traditional cardiac risk profile, studies have found elevated levels of coronary artery calcium, a marker for atherosclerosis. These plaques may not always be stable and could lead to cardiac events during or after endurance events.

5. Sudden Cardiac Arrest (SCA)

Although rare, sudden cardiac arrest in endurance athletes usually occurs due to undiagnosed conditions like:

• Hypertrophic cardiomyopathy
• Arrhythmogenic right ventricular cardiomyopathy
• Coronary anomalies

Most of these conditions are silent and may only be revealed through advanced monitoring techniques.

6. Exertional Hypertension

Long-distance runners may experience significant blood pressure spikes during races or intense training. Over time, this can lead to left ventricular hypertrophy and increased risk of stroke and heart failure.

Why Symptoms May Be Missed

Many runners pride themselves on high pain tolerance and are conditioned to ignore minor symptoms. However, subtle signs like:

• Palpitations at night
• Shortness of breath despite fitness
• Exercise intolerance
• Elevated heart rate at rest or during sleep

… could indicate something more serious than overtraining.

The Role of Long-Term ECG Monitoring in Runners

Traditional screening methods like resting ECGs or short-duration Holter exams may not always reflect how the heart behaves during exertion or recovery.

That’s where chest-strap-based, long-term ECG devices such as the wellness-focused Frontier X2 come in. These personal ECG tools record heart data continuously, providing a comprehensive view of cardiac activity during daily routines, exercise, and rest.

Key Benefits for Runners:

• Record ECG during training and rest, allowing their healthcare providers to review potential irregularities such as unusual beats or rhythm patterns.
• Track heart rate variability (HRV) and physiological strain to understand training intensity and recovery trends.
• Deliver high-resolution ECG-quality data that can support clinical review or research use when appropriately supervised by healthcare professionals.
• Provide insights into rhythm patterns to help users and clinicians discuss whether observed changes may warrant further evaluation.
• Capture heart rate trends during sleep and recovery for a complete picture of cardiac performance.
• Measure body shock levels, reflecting the mechanical stress your body experiences with every stride – a valuable indicator for optimizing running form and preventing overtraining.

Frontier X2 offers a non-invasive, patchless, and sweat-resistant option – ideal for runners who want to train smarter and safer.

When Should Long Distance Runners Be Concerned?

Here are a few scenarios  when runners should consider a deeper cardiac evaluation:

• Unexplained fatigue or reduced performance
• Heart palpitations during or after exercise
• Family history of sudden cardiac death
• Dizziness or fainting episodes
• Elevated heart rate at rest or while sleeping
• Chest discomfort unrelated to effort

In such cases, a long-term ECG monitor can provide crucial insight that a regular smartwatch or fitness tracker simply cannot.

Prevention: Running with Heart-Smart Awareness

While the risks exist, it doesn’t mean athletes should stop running. Instead, awareness and proactive heart monitoring can mitigate risks significantly.

Pro Tips for Long Distance Runners:

• Get screened: Periodic cardiac checkups with ECG and echocardiography
• Hydrate and fuel smartly: Avoid electrolyte imbalance, especially in long races
• Track your heart: Use clinically validated ECG monitors, especially during high-intensity training blocks
• Listen to your body: Fatigue, dizziness, or irregular heartbeat shouldn’t be ignored
• Limit excessive volume: Allow proper rest periods and consider de-training phases to avoid chronic stress

Final Thoughts

The athletic lifestyle offers immense cardiovascular benefits, but ultra-endurance training is not without its risks. What’s important is not to fear these risks – but to understand and manage them effectively.

By leveraging tools like long-term ECG monitors, runners can go the extra mile safely, with real-time insights into how their heart is responding to stress, exertion, and recovery.

Remember:

It’s not just about how far or fast you run – it’s about how well your heart handles the journey.

FAQs
1: Can long-distance running cause heart problems?

Yes. Intense, prolonged running can sometimes lead to arrhythmias, heart enlargement, or scarring in some individuals.

2: What are the early signs of heart issues in runners?

Shortness of breath, chest pain, dizziness, or irregular heartbeat – especially during or after exercise – can be warning signs.

3: How can runners lower their risk of cardiac events?

Regular check-ups, smart training, hydration, and using a continuous ECG monitor help reduce risk.

4: Is heart rate monitoring enough for endurance athletes?

Not always. Heart rate tracking misses arrhythmias – continuous ECG offers deeper insight into heart rhythm.

5: Does endurance running increase the risk of AFib?

Yes, over time. Long-term high-intensity training may increase the risk of AFib, especially in older male athletes.