related energy expenditure is applied one example is the case of a single device used to measure the caloric expenditure of a runner wearing weights for which m is the total mass of the runner and the weights another example is the use of multiple sensors on the trunk and extremities to more accurately measure the energy expenditure in those different parts of the body for which the total mass of the wearer is distributed among energy expenditure formulas applied to the outputs of each of the respective sensors for purposes of this disclosure no distinction is made between mass and weight fig1 depicts an illustrative embodiment of a physical activity monitoring device 100 in accordance with the present invention the physical activity monitoring device 100 provides proper operation and accuracy when physically associated in substantially any direction and orientation relative to the user in addition the device 100 provides visible audible e g alarms tones human speech and or tactile feedback to the user in one embodiment the physical activity monitor 100 includes an x axis sensor 102 a y axis sensor 104 a z axis sensor 106 a signal multiplexer and analog to digital converter a d 110 a data processor 112 a program and data memory 120 a user display and controls 122 a real time clock 124 an audio output converter 130 a speaker 132 one or more tactile vibration outputs 134 a pc network interface 150 a wireless networking antenna 152 a wired networking connector 154 a battery charger connector 160 and.