Differentiating Physiology from Pathology: The Gray Zones of the Athlete's Heart.

Routine vigorous exercise can lead to electrical, structural, and functional adaptations that can enhance exercise performance. There are several factors that determine the type and magnitude of exercise-induced cardiac remodeling (EICR) in trained athletes. In some athletes with pronounced cardiac remodeling, there can be an overlap in morphologic features with mild forms of cardiomyopathy creating gray zone scenarios whereby distinguishing health from disease can be difficult. An integrated clinical approach that factors athlete-specific characteristics (sex, size, sport, ethnicity, and training history) and findings from multimodality imaging are essential to help make this distinction.