Mechanisms of exercise-induced cardiac growth.

Exercise is a well-established intervention for the prevention and treatment of cardiovascular disease. Increase in cardiomyocyte size is likely to be the central mechanism of exercise-induced cardiac growth, but recent research also supports a role for the generation of new cardiomyocytes as a contributor to physiological cardiac growth. Other cardiac cell types also respond to exercise. For example, endothelial cells are important for the regulation of large vessels and expansion of microvasculature in meeting demands of the growing heart. Cardiac fibroblasts are known to generate and respond to important signals from their environment, but their role in exercise is less well defined. Therefore, cardiac growth relies on complex, finely regulated and interdependent signaling pathways as well as cross-talk among cardiac cell types.