Systems and methods are disclosed to enable a user to favorably coordinate the timing of musculoskeletal movement and skeletal muscle contraction and relaxation with the cardiac pumping cycle in order to improve perfusion of cardiac and peripheral skeletal muscle and other tissues, increase physiological efficiency, decrease myocardial stress, and enhance individual performance, health and safety during rhythmic physical activity. Additionally, systems and methods are disclosed to enable a user to avoid inadvertent unfavorable coordination of musculoskeletal movement and skeletal muscle contractions and relaxation cycles with the cardiac pumping cycle during physical activity.
