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 underlie 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]