title: The effects of creatine supplementation on thermoregulation and physical (cognitive) performance: a review and future prospects.
abstract: Creatine (Cr) is produced endogenously in the liver or obtained exogenously from foods, such as meat and fish. In the human body, 95 % of Cr is located in the cytoplasm of skeletal muscle either in a phosphorylated (PCr) or free form (Cr). PCr is essential for the immediate rephosphorylation of adenosine diphosphate to adenosine triphosphate. PCr is rapidly degraded at the onset of maximal exercise at a rate that results in muscle PCr reservoirs being substantially depleted. A well-established strategy followed to increase muscle total Cr content is to increase exogenous intake by supplementation with chemically pure synthetic Cr. Most Cr supplementation regimens typically follow a well-established loading protocol of 20 g day(-1) of Cr for approximately 5-7 days, followed by a maintenance dose at between 2 and 5 g day(-1) for the duration of interest, although more recent studies tend to utilize a 0.3-g kg(-1) day(-1) supplementation regimen. Some studies have also investigated long-term supplementation of up to 1 year. Uptake of Cr is enhanced when taken together with carbohydrate and protein and/or while undertaking exercise. Cr supplementation has been shown to augment muscle total Cr content and enhance anaerobic performance; however, there is also some evidence of indirect benefits to aerobic endurance exercise through enhanced thermoregulation. While there is an abundance of data supporting the ergogenic effects of Cr supplementation in a variety of different applications, some individuals do not respond, the efficacy of which is dependent on a number of factors, such as dose, age, muscle fiber type, and diet, although further work in this field is warranted. Cr is increasingly being used in the management of some clinical conditions to enhance muscle mass and strength. The application of Cr in studies of health and disease has widened recently with encouraging results in studies involving sleep deprivation and cognitive performance.
authors.affiliation: Centre for Sports and Exercise Medicine, William Harvey Research Institute, Queen Mary University of London, Mile End, London, E1 4NS, UK.
authors.forename: R
authors.initials: R
authors.lastname: Twycross-Lewis
authors.affiliation: Applied Science, Technology, Exercise and Medicine (A-STEM) Research Centre, College of Engineering, Swansea University, Bay Campus, Fabian Way, Swansea, SA1 8EN, UK.
authors.forename: L P
authors.initials: LP
authors.lastname: Kilduff
authors.affiliation: FIMS Reference Collaborating Centre of Sports Medicine for Anti-Doping Research, University of Brighton, 30 Carlisle Road, Eastbourne, BN20 7SN, UK.
authors.forename: G
authors.initials: G
authors.lastname: Wang
authors.affiliation: FIMS Reference Collaborating Centre of Sports Medicine for Anti-Doping Research, University of Brighton, 30 Carlisle Road, Eastbourne, BN20 7SN, UK. y.pitsiladis@brighton.ac.uk.
authors.forename: Y P
authors.initials: YP
authors.lastname: Pitsiladis
mesh_terms: D000818:Animals; D001833:Body Temperature Regulation / Q000187:drug effects*; D003071:Cognition / Q000187:drug effects*; D003401:Creatine / Q000493:pharmacokinetics / Q000494:pharmacology*; D006801:Humans; D018482:Muscle, Skeletal / Q000502:physiology*; D013997:Time Factors
chemical_list: D003401:Creatine
keywords: Cognitive function; Creatine supplementation; Health and disease; Physical performance; Sleep deprivation; Thermoregulation