What Lifelong Endurance Sports Do to Your Heart
Share
Introduction
Endurance athletes—runners, cyclists, rowers, and triathletes—are often seen as models of heart health. Regular training builds strong hearts, improves circulation, and reduces the risk of many diseases. But what happens when the training goes on for decades? Can years of intense endurance exercise change the heart in ways that aren't always helpful?
A new study looked at the heart health of lifelong and retired endurance athletes over the age of 40. The results may surprise you—and offer some important lessons for anyone who trains hard year after year.
How the Heart Adapts to Endurance Exercise
When you regularly do endurance activities, your heart becomes more efficient. This is known as “athlete’s heart,” and it includes:
- Larger heart chambers, especially the left ventricle, which pumps blood out to the body
- Stronger heart muscles
- Slower resting heart rate, a sign of better efficiency
These changes are usually healthy and help athletes perform better and recover faster. But with many years of high-volume training, some changes can go beyond normal adaptation.
What the Study Found
Researchers studied over 180 master endurance athletes (some still active, others retired) and compared them with a group of non-athletic adults of the same age.
Key findings included:
- About one in three endurance athletes had atrial fibrillation (AF)—a common type of irregular heartbeat. None of the non-athletes had it.
- 9% of athletes had short episodes of ventricular rhythm problems, compared to just 1% in non-athletes.
- Scarring of the heart muscle (called fibrosis) was more common in athletes, and it didn’t go away even after retiring.
- Active athletes had larger hearts, but retired athletes’ hearts were more similar in size to non-athletes—showing that some changes may reverse after stopping intense training.
What Does This Mean for Athletes?
The study suggests that while endurance training offers many health benefits, it may also increase the risk of certain heart rhythm problems over time—especially if the training is intense and long-term.
Some changes, like enlarged heart chambers, may shrink back after retiring or reducing training. But other changes, like scarring and rhythm disturbances, might be long-lasting.
The key takeaway: Even highly trained, healthy-looking athletes can develop silent heart issues.
Should You Be Concerned?
Not everyone who trains hard will have heart problems. In fact, most endurance athletes live long, healthy lives. But it’s smart to be aware of the risks and take steps to monitor your heart health, especially as you age.
Warning signs to watch for:
- Feeling your heart race or skip beats
- Dizziness or fainting
- Shortness of breath during easy workouts
- Unusual fatigue
Even if you feel fine, routine check-ups and heart screenings are a good idea if you’ve been training intensely for many years.
Smart Steps for Lifelong Athletes
Here’s how endurance athletes can protect their hearts while still enjoying the sports they love:
- Get regular heart check-ups – Ask about an ECG or heart rhythm monitor if you’ve trained for years.
- Listen to your body – Don’t ignore signs like fluttering, fatigue, or breathlessness.
- Moderate your intensity – Mix high-intensity sessions with easy days and recovery.
- Don’t skip rest – Recovery is when your heart heals and adapts.
- Know your family history – Genetics can play a role in heart rhythm disorders.
Conclusion
Lifelong endurance sports build strength, discipline, and stamina—but they may also lead to lasting changes in the heart. While most of these changes are healthy, some can increase the risk of arrhythmias, even after retirement from sport.
The best approach? Stay active, stay informed, and work with your doctor to keep your heart strong for the long run.