Regular intensive physical exertion results in physiological functional and structural adaptations termed athlete’s heart. Physiological remodelling may occasionally overlap with pathological changes of subtle or early cardiomyopathy (especially hypertrophic, dilatative or arrhythmogenic right ventricular cardiomyopathy). The differentiation between physiological remodelling and pathologic changes can be made in most cases by means of personal and family history, demographics and basic noninvasive cardiac investigations such as electrocardiogram, echosonography and exercise testing. Infrequently, additional tests including cardiac magnetic resonance imaging, detraining or/and genetic testing may be helpful. A proper evaluation of changes is crucial in order to avoid unnecessary disqualifications of athletes due to erroneous diagnosis of cardiomyopathy and to prevent misinterpretation of subtle pathological indicators as training-related and thereby exposing such individuals to increased risk of adverse events including sudden cardiac death during vigorous exercise.