title: Is running performance enhanced with creatine serum ingestion?
abstract: Runners Advantage (RA) creatine (Cr) serum has been marketed to increase running performance. To test this claim, cross-country runners completed baseline testing (BASE), an outdoor 5,000-m run followed by treadmill Vo(2)max testing on the same day. Subjects repeated testing after ingesting 5 ml of RA (n = 13) containing 2.5 g of Cr or placebo (n = 11). Heart rate (HR), rating of perceived exertion (RPE), and run time were recorded. With RA (56.48 +/- 8.93 ml.kg(-1.)min(-1)), Vo(2)max was higher (p = 0.01) vs. BASE (54.07 +/- 9.36 ml.kg(-1.)min(-1)), yet the magnitude of the increase was within the coefficient of variation of Vo(2)max. No effect of RA on maximal HR was exhibited, yet Vco(2)max and duration of incremental exercise were significantly higher (p < 0.025) vs. BASE. Vo(2)max was similar in PL (58.85 +/- 6.67 ml.kg(-1).min(-1)) and BASE (57.28 +/- 7.22 ml.kg(-1.)min(-1)). With RA, the 5,000-m time was unchanged, and RPE was lower (p < 0.025) vs. BASE. These data do not support the ergogenic claims of RA in its current form and dose.
authors.affiliation: Department of Kinesiology, California State University, San Marcos, California 92096, USA. astorino@csusm.edu
authors.forename: Todd A
authors.initials: TA
authors.lastname: Astorino
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Marrocco
authors.forename: Sara M
authors.initials: SM
authors.lastname: Gross
authors.forename: David L
authors.initials: DL
authors.lastname: Johnson
authors.forename: Colleen M
authors.initials: CM
authors.lastname: Brazil
authors.forename: Michelette E
authors.initials: ME
authors.lastname: Icenhower
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Kneessi
mesh_terms: D000328:Adult; D003401:Creatine / Q000627:therapeutic use*; D019587:Dietary Supplements; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology; D012420:Running / Q000502:physiology*; D016037:Single-Blind Method
chemical_list: D003401:Creatine