Can Fitness Mask A Heart Rhythm Problem?

For many active adults, a low resting heart rate is seen as proof of strong cardiovascular health. Runners, cyclists, swimmers, and regular gym-goers often notice their heart rate sitting below 60 beats per minute—something that usually reflects consistent training and endurance. However, there are times when a slower pulse may not just be a sign of fitness but an indication that the heart’s electrical system needs attention. Dr Sanjeev Gera, Senior Director, Interventional Cardiologist, Fortis Noida, answered this for Times Now Digital. Heart rhythm disorders, particularly bradycardia—an abnormally slow heart rate—are often associated with ageing or underlying heart disease. Yet they can also appear in people who look and feel perfectly healthy.

The challenge is that, in highly active individuals, the line between physiological adaptation and pathology can become blurred.

When is a slow heart rate normal, and when is it not?

Endurance training increases vagal tone, which slows the heart rate at rest. For athletes, a resting pulse of 45–55 beats per minute may be entirely normal and not require intervention. However, problems arise when the slow rate is accompanied by symptoms such as the following:

1. Unexplained fatigue despite regular training
2. Dizziness or light-headedness
3. Near-fainting or fainting episodes
4. Shortness of breath disproportionate to effort
5. Reduced exercise tolerance

Because active adults are accustomed to pushing through discomfort, these signs may be dismissed as dehydration, overtraining, stress, or lack of sleep. In some cases, even fitness trackers may reinforce the assumption that “low is good," without distinguishing between healthy conditioning and electrical dysfunction.

The hidden nature of rhythm disorders

The heart’s rhythm is controlled by an electrical system. When this system malfunctions due to age-related degeneration, underlying conduction disease, or other factors, the heart may beat too slowly, pause unexpectedly, or fail to respond appropriately during exertion. In fit individuals, strong cardiac muscle and efficient circulation can temporarily compensate for electrical issues. This means symptoms may be subtle at first. A person may continue exercising, unaware that their heart rate is not increasing adequately during activity or that pauses are occurring at rest or during sleep.Over time, however, untreated rhythm disorders can lead to significant complications, including falls due to fainting spells, worsening fatigue, or, in rare cases, more serious cardiac events.Read more: Top 10 Heart-Healthy Diets to Follow in 2026 for Better Cardiovascular Health

Why early evaluation matters

One of the most important steps active adults can take is to pay attention to change. A long-standing low resting heart rate that has always felt normal is different from a new pattern of exhaustion, reduced stamina, or episodes of blacking out. A simple ECG, Holter monitoring, or extended rhythm monitoring can help distinguish athletic conditioning from conduction abnormalities. Cardiologists assess not only the heart rate but also how the rhythm behaves during activity, rest, and recovery. Early diagnosis allows for timely intervention. In confirmed cases of symptomatic bradycardia or advanced conduction block, pacemaker therapy may be recommended. While the idea of a device can sound daunting to a young or active individual, pacing technology has evolved significantly in recent years.A new era in cardiac pacingTraditional pacemakers use leads (wires) that connect a pulse generator to the heart. Though highly effective, these systems can be associated with lead-related complications over time.Newer leadless pacemakers represent a major advancement in rhythm management. These miniature, self-contained devices are implanted directly into the heart via a minimally invasive, catheter-based procedure, eliminating the need for transvenous leads. For appropriate candidates, this approach reduces infection risk, avoids visible chest scars or bulges, and often allows quicker recovery—an important consideration for active individuals eager to return to their routines.Importantly, having a pacemaker does not mean giving up an active lifestyle. With proper medical guidance, many patients resume walking, cycling, swimming, and even structured fitness programmes.Read more: Heart-Healthy Exercises You Should Actually DoListening beyond the fitness trackerWearable technology has empowered people to track steps, calories, and heart rate trends. However, numbers alone cannot replace clinical evaluation. A consistently low heart rate is not automatically a sign of peak fitness, especially if accompanied by symptoms.True heart health goes beyond performance statistics. Paying attention to unusual fatigue, dizziness, or changes in stamina and seeking timely medical advice can make a critical difference. Staying active is important, but so is understanding how your heart’s electrical system functions. When in doubt, take the step to get checked and consciously decode your rhythm to ensure that fitness and safety go hand in hand.