A physiological monitoring system includes a sensor subsystem worn by a person including at least one physiological sensor. A dock associated with the sensor subsystem includes a first connector component electrically connected to the physiological sensor. A portable transmitting unit is received by the dock and includes a transmitter and a connector component removeably mateable with the dock connector component to route physiological data to the transmitter. A base station receives and displays physiological data. A portable relay unit includes a receiver for receiving physiological data from the portable transmitting unit, a transmitter for relaying physiological data to the base station, an antenna subsystem for the receiver and transmitter, and a portable power source for the receiver and transmitter.