title: Caffeine and 3-km cycling performance: Effects of mouth rinsing, genotype, and time of day.
abstract: We assessed the efficacy of caffeine mouth rinsing on 3-km cycling performance and determined whether caffeine mouth rinsing affects performance gains influenced by the CYP1A2 polymorphism. Thirty-eight recreational cyclists completed four simulated 3-km time trials (TT). Subjects ingested either 6 mg/kg BW of caffeine or placebo 1 h prior to each TT. Additionally, 25 mL of 1.14% caffeine or placebo solution were mouth rinsed before each TT. The treatments were Placebo, caffeine Ingestion, caffeine Rinse and Ingestion+Rinse. Subjects were genotyped and classified as AA homozygotes or AC heterozygotes for the rs762551 polymorphism of the CYP1A2 gene involved in caffeine metabolism. Magnitude-based inferences were used to evaluate treatment differences in mean power output based on a predetermined meaningful treatment effect of 1.0%. AC heterozygotes (4.1%) and AA homozygotes (3.4%) benefited from Ingestion+Rinse, but only AC performed better with Ingestion (6.0%). Additionally, Rinse and Ingestion+Rinse elicited better performance relative to Placebo among subjects that performed prior to 10:00 h (Early) compared with after 10:00 h (Late). The present study provides additional evidence of genotype and time of day factors that affect the ergogenic value of caffeine intake that may allow for more personalized caffeine intake strategies to maximize performance.
authors.affiliation: Department of Kinesiology, James Madison University, Harrisonburg, VA, USA.
authors.forename: M W
authors.initials: MW
authors.lastname: Pataky
authors.affiliation: Department of Kinesiology, James Madison University, Harrisonburg, VA, USA.
authors.forename: C J
authors.initials: CJ
authors.lastname: Womack
authors.affiliation: Department of Kinesiology, James Madison University, Harrisonburg, VA, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Saunders
authors.affiliation: Department of Kinesiology, James Madison University, Harrisonburg, VA, USA.
authors.forename: J L
authors.initials: JL
authors.lastname: Goffe
authors.affiliation: Department of Kinesiology, James Madison University, Harrisonburg, VA, USA.
authors.forename: A C
authors.initials: AC
authors.lastname: D'Lugos
authors.affiliation: Department of Kinesiology, James Madison University, Harrisonburg, VA, USA.
authors.forename: A
authors.initials: A
authors.lastname: El-Sohemy
authors.affiliation: Department of Kinesiology, James Madison University, Harrisonburg, VA, USA.
authors.forename: N D
authors.initials: ND
authors.lastname: Luden
mesh_terms: D058956:Administration, Mucosal; D000284:Administration, Oral; D054874:Athletic Performance / Q000502:physiology*; D002110:Caffeine / Q000008:administration & dosage / Q000494:pharmacology*; D002940:Circadian Rhythm / Q000502:physiology; D019388:Cytochrome P-450 CYP1A2 / Q000235:genetics*; D004311:Double-Blind Method; D005080:Exercise Test; D005260:Female; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D008297:Male; D009061:Mouth Mucosa; D009067:Mouthwashes; D058573:Performance-Enhancing Substances / Q000008:administration & dosage / Q000494:pharmacology*; D020641:Polymorphism, Single Nucleotide; D013997:Time Factors; D055815:Young Adult
chemical_list: D009067:Mouthwashes; D058573:Performance-Enhancing Substances; D002110:Caffeine; C504573:CYP1A2 protein, human; D019388:Cytochrome P-450 CYP1A2
keywords: CYP1A2; circadian rhythm; genetics; mouthwash