This article explores the first attempt by American physiologists to assist employers with the stubborn problem of tired workers. It examines the work of Frederic Lee and the Committee on Industrial Fatigue, which was set up to increase productivity in the face of the long hours deemed necessary for war readiness. Despite the biomedical investigators' strenuous efforts and their incisive critique of Taylorism, however, corporate management found few practical uses for their findings and remedial proposals. Instead, industrial physiology helped to pave the way for rival consultants from psychology.