Long-term high-intensity physical activity is associated with morphological 
changes, termed as the 'athlete's heart'. The differentiation of physiological 
cardiac adaptive changes in response to high-level exercise from pathological 
changes consistent with an inherited cardiomyopathy is imperative. 
Cardiovascular magnetic resonance (CMR) imaging allows definition of abnormal 
processes occurring at the tissue level, including, importantly, myocardial 
fibrosis. It is therefore vital in accurately making this differentiation. In 
this review, we will review the role of CMR imaging of fibrosis, and detail CMR 
characterisation of myocardial fibrosis in various cardiomyopathies, and the 
implications of fibrosis. Additionally, we will outline advances in imaging 
fibrosis, in particular T1 mapping. Finally we will address the role of CMR in 
pre-participation screening.