Defining, measuring, and monitoring resilience for the tactical professional: Part 1-Allostatic load theory: Principles for the tactical professional at home and on the job

The allostasis model describes an increased vulnerability to physical breakdown and dysregulation that occurs as a person is exposed to stress levels above which they can adapt. Essentially, the body seeks to maintain a consistent internal environment that is also ready to respond to an ever-changing external environment. This principle is widely known as homeostasis, and is the underlying foundation of all human physiology. However, the body's effort to maintain homeostasis is not purely reactive. The allostasis model theorizes that true homeostatic control requires some anticipation. When a person's capacity to anticipate changes requiring control fails, the reactive processes within the body become persistently activated, as if they were constantly responding to danger. While this stress response activation is typically low-grade in nature, the health and performance consequences of this overactivity can build up over time to become much more severe.