The effect of body-mediated energy transfer and harvesting on biological tissues has not been considered yet. We demonstrate through clinical protocols that body-mediated energy harvesting concentrates inevitable and local electric fields in biological tissues, which reduces muscle fatigue (6.4%, P-value = 0.020). The waveform (AC and DC) and intensity (∼3000 mV/mm) of these electric fields can be adjusted by controlling several variables (grounding method, external resistance, charging capacitor) depending on the purpose (usefulness, energy strength) without using any additional
battery or wiring. Moreover, the harvested energy can be used to operate small electronic devices semipermanently. These findings indicate that body-mediated energy harvesting is a promising solution for powering wearable technologies and as a noninvasive treatment for harvesting energy and stimulating biological tissues synchronously.

Funding Information
*National Research Foundation of Korea (NRF) (No. 2021R1A4A3030268)
*Korea Drug Development Fund (HN21C1410000021)