Athletes Heart: Symptoms, Types, Causes and Treatment

The term "athlete's heart" describes the structural and functional changes that occur in the hearts of individuals who regularly engage in intense physical training. While these adaptations are usually benign and reflect the heart’s remarkable ability to meet the increased demands of athletic performance, they can sometimes mimic or mask underlying heart disease. Understanding athlete’s heart is crucial for athletes, coaches, and healthcare providers to distinguish between normal physiological changes and potentially dangerous cardiac conditions.

Symptoms of Athletes Heart

Athlete’s heart often manifests subtly, with many individuals experiencing little to no symptoms. However, some athletes may notice changes or develop concerns that prompt medical attention. Recognizing these symptoms—and differentiating them from signs of true heart disease—is essential for safe sports participation and peace of mind.

Symptom	Description	Typicality	Source(s)
Bradycardia	Slow resting heart rate (often <60 bpm)	Common	1 3 5 7
Palpitations	Sensation of irregular or forceful heartbeats	Occasional	1 3 5
Dizziness	Lightheadedness, especially at rest	Occasional	1 3
Chest pain	Mild, non-specific discomfort	Rare	1 2 5
Fatigue	Unusual tiredness during or after exercise	Uncommon	1 5
Dyspnoea	Breathlessness, especially on exertion	Uncommon	1 3

Table 1: Key Symptoms

Common Clinical Features

Athletes frequently present with a slow resting pulse (bradycardia), which is usually a benign adaptation to training. This lower heart rate is often accompanied by other changes such as mild palpitations or occasional dizziness, especially when transitioning from lying down to standing 1 3 5. These symptoms are rarely severe and often resolve with continued adaptation or minor adjustments in training.

When Symptoms Signal a Problem

Most symptoms associated with athlete's heart are not dangerous. However, certain features—especially if new, severe, or associated with exercise—warrant further investigation:

• Chest pain on exertion: Though rare, this can indicate cardiac involvement, especially if persistent after viral infections (e.g., COVID-19) 2.
• Abnormal tachyarrhythmias: Rapid or irregular heart rhythms during exercise are not typical of athlete’s heart and may signify underlying disease 5 15.
• Syncope (fainting): Especially during or immediately after exertion, this always requires medical evaluation.

Physical and Diagnostic Findings

Physical examination may reveal:

• A soft systolic murmur (due to increased stroke volume)
• Sinus bradycardia (resting pulse well below normal)
• Non-specific ECG changes, such as ST elevation or T wave changes

It’s vital to distinguish these benign findings from those seen in cardiomyopathies or other pathologies 3 5 8 13. Advanced imaging and testing may be required in ambiguous cases.

Types of Athletes Heart

Not all athlete’s hearts are created equal. The specific changes depend largely on the type of athletic training, with endurance and strength training producing different patterns of cardiac adaptation.

Type	Main Features	Associated Sport	Source(s)
Eccentric LVH	Enlarged chamber, modest wall thickening	Endurance (running)	4 6 7 8 9
Concentric LVH	Increased wall thickness, normal chamber	Strength (lifting)	4 6 7 9
Mixed	Both chamber and wall thickening	Rowing, cycling	6 7 9 10
Electrical	ECG changes (bradycardia, arrhythmias)	Any	3 5 13 15

Table 2: Types of Athlete's Heart

Eccentric vs. Concentric Hypertrophy

Eccentric Left Ventricular Hypertrophy (LVH)

• Seen in: Endurance athletes (runners, swimmers)
• Features: Enlarged left ventricular (LV) chamber, proportionate mild wall thickening
• Mechanism: Chronic volume load from sustained high cardiac output
• Result: Enhanced filling and pumping capacity 4 6 7 8 9

Concentric Left Ventricular Hypertrophy

• Seen in: Strength athletes (weightlifters, wrestlers)
• Features: Increased LV wall thickness, normal or near-normal chamber size
• Mechanism: Repeated pressure overload from heavy lifting
• Result: Heart adapts to pump against higher resistance 4 6 7 9

Mixed Adaptations

• Seen in: Sports combining endurance and strength (cycling, rowing)
• Features: Both chamber enlargement and wall thickening to varying degrees
• Mechanism: Combined volume and pressure load 6 7 9 10

Electrical and Functional Variants

• Bradycardia and conduction changes: Sinus bradycardia is common; sometimes, benign arrhythmias or conduction delays appear on ECG 3 5 13 15.
• ECG findings: ST segment elevation, T-wave changes, and even mild arrhythmias may be present but typically reflect physiological adaptation, not disease 3 5 8.

Not All Athletes Develop Athlete’s Heart

It’s important to note that not every athlete—regardless of training intensity—will develop significant cardiac enlargement. Genetic factors, training duration, and type of sport all influence the degree of adaptation 9.

Causes of Athletes Heart

Understanding what drives the changes in athlete’s heart helps to clarify why these adaptations occur and how they can sometimes be confused with disease.

Cause	Mechanism	Impact	Source(s)
Intense Training	Chronic volume/pressure overload	Cardiac remodeling	1 4 6 7 9
Exercise Type	Dynamic vs static activity	Eccentric vs concentric	4 6 7 9
Genetic Factors	Individual variability	Degree of adaptation	9 17
Physiological	Neurohormonal and metabolic responses	Improved efficiency	1 4 7 14 17

Table 3: Causes of Athlete's Heart

The Role of Exercise Intensity and Type

Dynamic (Endurance) Exercise

• Examples: Running, swimming, cycling
• Effect: Increases cardiac output and volume load (eccentric hypertrophy)
• Result: Heart adapts by enlarging chambers to handle greater blood flow 4 6 7

Static (Strength) Exercise

• Examples: Weightlifting, wrestling
• Effect: Increases blood pressure and pressure load (concentric hypertrophy)
• Result: Heart walls thicken to pump against higher resistance 4 6 7

Physiological Adaptations

Adaptations involve:

• Increased stroke volume
• Reduced heart rate at rest
• Enhanced myocardial efficiency

These changes result from neurohormonal and metabolic signaling that occurs with repeated, intense training 1 4 7 14.

Genetic and Individual Factors

Not all athletes experience the same degree of heart adaptation. Genetics, age, sex, and body size contribute to variability. Some athletes—especially those with a family history of heart disease—may develop patterns that overlap with pathological conditions, making diagnosis more challenging 9 17.

Differentiating Physiology from Pathology

The overlap between athlete’s heart and certain cardiomyopathies, such as hypertrophic cardiomyopathy (HCM), is a key area of clinical concern. Advanced imaging (echocardiography, cardiac MRI), exercise testing, and sometimes genetic testing are used to distinguish between the two 8 13 14 17.

Treatment of Athletes Heart

Athlete’s heart itself is a benign and reversible condition that generally requires no treatment. However, careful assessment is essential to exclude pathology, address symptoms, and provide appropriate advice about sports participation.

Approach	Purpose	Typical Action	Source(s)
Reassurance	Confirm benign adaptation	Education, monitoring	1 3 5 13 17
Exclude Pathology	Rule out cardiomyopathy or disease	Imaging, ECG, testing	8 13 14 17
Symptom Management	Address palpitations, dizziness, etc.	Adjust training	1 5 15
Restriction	For confirmed heart disease (not athlete's heart)	Limit/stop sports	8 12 15 16

Table 4: Treatment and Management Approaches

Reassurance and Monitoring

For most athletes, once athlete’s heart is diagnosed and pathology is excluded:

• No treatment is necessary
• Athletes can continue training and competition
• Regular follow-up may be advised, especially if cardiac size is near upper limits or symptoms develop 1 3 5 13 17

Diagnostic Evaluation

A stepwise approach is recommended:

1. History and Physical Exam: Including personal and family history
2. ECG and Echocardiogram: To assess for chamber size, wall thickness, and function
3. Advanced Imaging: Cardiac MRI if ambiguity persists
4. Further Testing: Exercise testing, Holter monitoring, or genetic evaluation if indicated 8 13 14 17

Managing Symptoms

Minor symptoms (palpitations, mild dizziness) usually do not require intervention. Adjustments in training, hydration, and electrolyte balance may help. More severe symptoms—especially exertional chest pain or syncope—require thorough evaluation and may indicate underlying heart disease 1 5 15.

When to Restrict Activity

If investigations reveal:

• True cardiomyopathy (e.g., HCM)
• Myocarditis or other inflammatory conditions
• Dangerous arrhythmias

Then restriction from competitive sports may be necessary until the condition is managed 8 12 15 16. Gradual return to play is considered only after careful risk assessment and specialist guidance.

Special Considerations: Myocarditis and Arrhythmias

• Myocarditis: Athletes must abstain from exercise during the acute phase and until cardiac function normalizes 16.
• Arrhythmias: Individualized management, with a focus on risk stratification and, when possible, safe return to play 15.

Conclusion

Athlete’s heart represents the body’s remarkable ability to adapt to intense physical demands. While mostly benign, its overlap with serious cardiac conditions makes careful evaluation essential. Here’s what to remember:

• Key symptoms are usually mild (bradycardia, benign palpitations) but must be distinguished from those of heart disease.
• Types of athlete’s heart vary by sport, with endurance and strength activities producing different cardiac remodeling patterns.
• Causes are rooted in the physiological stress of repetitive, intense exercise; genetic factors also play a role.
• Treatment is generally unnecessary for true athlete’s heart, but a thorough workup is needed to rule out pathology. Lifelong monitoring and tailored advice ensure safety and optimal performance.

Summary:

• Athlete’s heart is a normal, adaptive response to long-term intensive training 1 4 6 7.
• Symptoms are mild; severe symptoms require investigation 1 5 15.
• Cardiac adaptations depend on sport type and individual factors 4 6 7 9.
• Diagnosis relies on history, imaging, and sometimes advanced testing 8 13 17.
• No treatment is needed unless underlying disease is found; reassurance and monitoring are key 1 3 5 17.
• Restriction from sport is reserved for those with confirmed cardiac disease 8 12 15 16.

By understanding the nuances of athlete’s heart, athletes and clinicians can work together to ensure both peak performance and safety on—and off—the field.