Human power is one form of renewable energy that has shown to be promising to provide a solution for powering personal electronic devices when other energy sources are not readily available while reducing environmental waste associated with battery disposal and eliminating the need for battery displacement. This paper introduces a new paradigm of human energy harvesting with the ultimate goal of producing wearable zero-net energy biosensors by reusing the hardware components to perform both harvesting and sensing functions. The proposed energy harvesting method uses two miniature electromagnetic generators as the respiratory effort energy harvester, while at the same time the output voltage waveform of the system can be used to estimate the respiratory rate and depth. Preliminary simulation and experimental results indicate that sufficient energy can be obtained to power an ultra low power microcontroller with low data rate wireless link.