Stress is an essential response in highly competitive environments. Before a race, before an exam, before an important meeting, your heart rate and blood pressure rise, your focus tightens, you become more alert and more efficient. But beyond a certain level, stress overloads your system, compromising your performance and, eventually, your health. So the question is: When does stress help and when does it hurt? To find out, HBR talked with Harvard Medical School professor Herbert Benson, M.D., founder of the Mind/Body Medical Institute. Having spent more than 35 years conducting worldwide research in the fields of neuroscience and stress, Benson is best known for his 1975 best seller The Relaxation Response, in which he describes how the mind can influence stress levels through such tools as meditation. His most recent research centers on what he calls"the breakout principle," a method by which stress is not simply reduced but carefully controlled so that you reap its benefits while avoiding its dangers. He describes a four-step process in which you first push yourself to the most productive stress level by grappling intently with a problem. Next, just as you feel yourself flagging, you disengage entirely by doing something utterly unrelated-going for a walk, petting a dog, taking a shower. In the third step, as the brain quiets down, activity paradoxically increases in areas associated with attention, space-time concepts, and decision making, leading to a sudden, creative insight-the breakout. Step four is achievement of a "new-normal state," in which you find that the improved performance is sustained, sometimes indefinitely. As counterintuitive as this research may seem, managers can doubtless recall times when they've had an "aha" moment at the gym, on the golf course, or in the shower. What Benson describes here is a way to tap into this invaluable biological tool whenever we want.