Basic research has demonstrated that myocardial inflammation may be a feature of systemic viral inflammation, resulting from agents such as influenza. Physical activity during exposure to pathogens has been shown to exacerbate the propensity to develop adverse cardiac events. As such, based upon empirical findings, current guidelines on athletic training deter athletes from participating in sport during common colds. Cardio-vascular Magnetic Resonance (CMR) allows for non-invasive visualization of myocardial inflammation, where it has emerged as the imaging modality of choice to assess the course of myocarditis. Thus, using CMR-based tissue characterization, we hypothesized that colds in elite high-endurance athletes would lead to depressed cardiac function and myocardial inflammation.