General Adaptation Syndrome

General adaptation syndrome is a theory of stress proposed by the Hungarian physician and endochrinologist Hans Selye. The theory states that when encountering stressors, the organism undergoes a predictable three-stage process when reacting to the stressors. The stages are:

Alarm phase, an acute phase in which the body mobilizes energy for a fast and intense response.

Resistance phase, in which the body also mobilizes energy, but as a longer term response, of lower intensity.

Exhaustion phase, where the body has been in the resistance phase so long, that it is drained of its energy resources, and is no longer able to maintain a response. In this stage, maladaptive diseases will occur.

Source:

Thomas, J. Q., Kotecki, J.E. (2011). Physical Activity & Health: An Interactive Approach, Third Edition. (pp. 216-217) Sudbury, MA: Jones and Bartlett