Daijiworld Media Network – Hebbal

Hebbal, Sep 27: Running is celebrated as one of the healthiest forms of exercise, improving stamina, mental health, and reducing the risk of chronic diseases. However, cardiologists are now cautioning that extreme endurance training may backfire, leading to myocardial fibrosis—a condition where scar tissue develops in the heart muscle, reducing flexibility and long-term function.

Dr Kumar Kenchappa, Consultant Interventional Cardiologist at Manipal Hospital Hebbal, explains, “Myocardial fibrosis develops over years of repetitive micro-injuries to the heart that don’t heal properly due to neglected rest. This scarring makes the heart less efficient, especially in young athletes who overtrain.”

Understanding the risk

Myocardial fibrosis occurs when repeated strain on the heart transforms tiny injuries into permanent scar tissue. Endurance athletes, such as marathoners and ultra-distance runners, are particularly vulnerable due to prolonged training hours and high weekly mileage. Studies published in the Journal of the American College of Cardiology indicate higher rates of myocardial fibrosis among long-term endurance athletes compared to recreational runners.

Warning signs to watch for

Dr Kenchappa stresses that the condition develops silently, but subtle signs may appear, including:

• Unusual chest discomfort
• Palpitations
• Sudden drop in performance
• Easy fatigue or prolonged recovery
• Breathlessness disproportionate to activity

Ignoring these symptoms can lead to arrhythmias or even heart failure. Early medical intervention can prevent permanent damage.

How much running is safe?

WHO guidelines recommend 150-300 minutes of moderate aerobic activity per week or up to 150 minutes of vigorous activity. Dr Kenchappa advises young runners not to exceed 60-70 km per week regularly. Structured training, cross-training with swimming or cycling, interval runs, and designated rest days help prevent repetitive heart strain. Maintaining hydration and electrolyte balance is also crucial.
Importance of heart check-ups

Preventive screenings—including ECG, echocardiograms, and treadmill tests—can detect early changes in heart function. “Routine cardiac check-ups are essential for young endurance athletes. Detecting fibrosis or abnormal rhythms early ensures safe training,” Dr Kenchappa notes.

Balanced training is key

Experts emphasize that running remains a powerful tool for health but must be balanced with rest and mindful training. “Respect your body, listen to warning signs, and train smart. Consistency and moderation build lifelong health, while excess can silently scar the heart,” says Dr Kenchappa.

As India embraces endurance sports, cardiologists urge athletes and recreational runners alike to avoid the “more is better” approach, keeping training safe while protecting heart health.