Endure: Mind, Body, and the Curiously Elastic Limits of Human Performance

by Alex Hutchinson

doctors and pain researchers have concluded that pain is fundamentally a subjective, situation-dependent phenomenon.21 For example, stress, fear, and anxiety activate an impressive array of brain chemicals, including endorphins (the body’s store-brand opioid drugs) and endocannabinoids (the body’s cannabis), to dull or completely block pain that would overwhelm you in other circumstances. In evolutionary terms, pain may serve a valuable function by telling you to stop and allow an injury to heal. “But if you’re a deer being chased by a wolf and you trip and break a leg,” says Mogil, the McGill pain researcher, “you need to forget about that pain until later.”