Stress in law enforcement can range from a rookie handing out his first citation to a seasoned veteran responding to a lethal attack. While each stressor has its own characteristics, the toll on the human body can be exceedingly destructive if not dealt with effectively. Since heart rate is one of many factors that can indicate stress levels in most people, monitoring heart rate is one of many methods to keep track of and control stress levels for some individuals. The “Optimal Performance Zone” was created with a range of 115 to 145 beats per minute (bpm). This zone was based on the onset of physical skill loss/improvement at specific heart rates. The studies used to incorporate heart rate into a generalized optimal performance zone involved physical exertion rather than psychological and/or emotional stress. Heart rate monitors have the potential to be one of the tools in the field of optimal human performance. Since lower stress levels potentially equate to greater chances of winning critical encounters, police trainers strive to facilitate the achievement of “optimal performance” through various techniques. In this article, “optimal performance” is discussed through heart rate monitoring.