Energy use is an important metric of environmental impact and manufacturing efficiency. However, a major component of energy analysis has yet to permeate life-cycle analysis methodology: the energy use associated with human labor. We will discuss a straightforward method of estimating the energy demands of an hour of industrial labor based on readily available national statistics. In the United States, this estimate yields 30 MJ of primary energy use per worker-hour (EPWH). These results can be applied to inform an expand the applications of process-based and hybrid economic input-output life-cycle assessment.