Some executives thrive under pressure. Others wilt. Is the reason all in their heads? Hardly. Sustained high achievement demands physical and emotional strength as well as a sharp intellect. To bring mind, body, and spirit to peak condition, executives need to learn what world-class athletes already know: recovering energy is as important as expending it. This article, which originally appeared in the January 2001 issue of Harvard Business Review, is offered in audio form exclusively through Audible.