Exerkine

An exerkine is a signaling molecule released in response to exercise that helps mediate systemic adaptations to exercise.^[1]

Exerkines come in many forms, including hormones, metabolites, proteins and nucleic acids; are synthesized and secreted from a broad variety of tissues and cell types; and exert their effects through endocrine, paracrine and/or autocrine pathways.^[2] These effects are thought to underly much of the health benefits of exercise in terms of enhanced resilience, healthspan and longevity.^[1][2]

The study of exerkines is the focus of the field of exercise endocrinology.^[3] Though the existence of exerkines had been speculated about as early as the 1960s,^[4] the identification of the first exerkine, IL-6, which is secreted from contracting muscles, didn't occur until 2000.^[5] In 2012 a new exerkine, irisin, was discovered and found to be involved in the regulation of energy expenditure,^[6] attracting significant scientific and public attention to the field.^{[7][8][9][10]} To date many thousands of potential exerkines have been identified,^[11][12] though only a limited number have been studied in any depth. Research is ongoing to understand how they function individually and in concert.^[3]

The word 'exerkine' was coined in 2016 by Mark Tarnopolsky and colleagues, based on a combination of the beginning of 'exercise' and the beginning of κίνησις (kínēsis, Ancient Greek for 'movement').^[1]