Embodiments include a system for determining cardiovascular information for a patient with coronary artery disease. The system may include at least one computer system configured to receive patient-specific data regarding a geometry of the patient's heart and create a model representing at least a portion of the patient's heart based on the patient-specific data. The at least one computer system may be further configured to create, for a given level of physical activity, a physics-based model of blood flow through the patient's heart simulated during a selected level of physical activity; determine and normalize one or more values of at least one blood flow characteristic within the patient's heart during the simulated level of physical activity; and compare the one or more normalized values of the at least one blood flow characteristic to a threshold to determine whether the level of physical activity exceeds an acceptable level of risk.