A heart rate monitor includes a user system (100) adjacent to a users skin in communication with a remote processing system (200). The user system includes a user processor (105), a user memory (110) coupled to the user processor, a clock signal generator (115) coupled to the processor, a sensing system (120) coupled to the processor for measuring at least a user heart rate, a user transceiver (125) coupled to the processor, a user interface (135) coupled to the processor, and a user antenna (145) coupled to the transceiver. A user battery (150) is coupled to the user processor, the user memory, the clock signal generator, the sensing system, and the user transceiver. The remote processing system includes a remote processor (205), a remote memory (210) coupled to the remote processor, a remote transceiver (225) coupled to the remote processor, and a remote antenna (245) coupled to the remote transceiver. The sensing system includes a blood concentration sensing system (310) configured to sense changes in blood concentration in one or more blood vessels beneath a surface of the skin, a motion sensor (320) for sensing changes in position of the heart rate monitor with respect to the skin, and an accelerometer (330) for sensing motion of the heart rate monitor with respect to a users heart.
