title: Growth hormone, exercise, and athletic performance: a continued evolution of complexity.
abstract: Growth hormone (hGH) presents pleiotropic effects in many tissues encompassing a diverse range of physiological actions. Its complexity as a family of hormones with different isoforms and different somatotroph molecular functions continues to challenge the status quo of our understanding of its release, function, and signaling. Owing to the fact that the majority of the literature has viewed hGH from the perspective of the primary 22 kD monomer, further investigation is needed as to the influence and biological activity of other aggregate and splice variant isoforms that are released into circulation. Its role over the life span and with supplementation yields equivocal results with more study needed. Testing for the use of hGH has progressed, and the first positive test was recently documented. Understanding of pituitary function and physiology will remain complex until the use of a broader range of analytical techniques, including assays, becomes mainstream.
authors.affiliation: Human Performance Laboratory, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, USA. William.Kraemer@uconn.edu
authors.forename: William J
authors.initials: WJ
authors.lastname: Kraemer
authors.forename: Courtenay
authors.initials: C
authors.lastname: Dunn-Lewis
authors.forename: Brett A
authors.initials: BA
authors.lastname: Comstock
authors.forename: Gwendolyn A
authors.initials: GA
authors.lastname: Thomas
authors.forename: James E
authors.initials: JE
authors.lastname: Clark
authors.forename: Bradley C
authors.initials: BC
authors.lastname: Nindl
mesh_terms: D054874:Athletic Performance / Q000502:physiology*; D004300:Doping in Sports / Q000379:methods*; D015444:Exercise / Q000502:physiology*; D019382:Human Growth Hormone / Q000032:analysis* / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D013997:Time Factors
chemical_list: D019382:Human Growth Hormone