A physiological monitor for measuring a pulsatile motion signal (MoCG) that is delayed from, but at the same rate as, the heartbeat of a user. In one embodiment, the system includes a housing configured to be worn on the body of a user at least one MoCG sensor, within the housing, that measures a pulsatile motion signal (MoCG) that is delayed from, but at the same rate as, the heartbeat of the user and at least one data processor that calculates, solely based on an output of the at least one MoCG sensor, at least one of (i) heart rate (HR) and activity level for the user, and (ii) respiratory rate (RR), stroke volume (SV), and cardiac output (CO) for the user. In another embodiment, the at least one data processor is within the housing.