title: Effect of caffeine on motor performance by caffeine-naive and -familiar subjects.
abstract: The purpose of this investigation was to assess the effect of caffeine on selected manipulation skills by caffeine-naive and caffeine-familiar subjects. The subjects were 20 caffeine-naive (less than 90 mg/d) and 20 caffeine-familiar (greater than 750 mg/d) college-age (21 +/- 1.7 yr.) women. Measurements included steadiness error time and frequency, duration of tracing, error time and frequency, and dexterity. Doses of 2.5, 5.0 mg.kg-1 body weight caffeine or a placebo (200 mg. methylcellulose) were administered randomly to all subjects on three separate occasions. A 2 x 3 repeated-measures analysis of variance yielded a significant group difference for steadiness error time between the 5 mg.kg-1 and 2.5 mg.kg-1 dose and between 5 mg.kg-1 and the placebo. For frequency of steadiness errors, the nonuser group posted significant gains for both 5.0 and 2.5 mg.kg-1 over the placebo control. On tracing error time and error frequency, 5.0 mg.kg-1 resulted in significant increases from both 2.5 mg.kg-1 and the placebo group. In the caffeine-naive group, both doses of caffeine led to significant increases in dexterity time from the placebo, and the 5.0 mg.kg-1 dose was significantly different from the 2.5 mg.kg-1 trial. It was concluded that caffeine had detrimental effects on selected performance skills of caffeine-naive women but not in caffeine-familiar women.
authors.affiliation: School of Health, Physical Education and Leisure, Oklahoma State University, Stillwater 74078.
authors.forename: B H
authors.initials: BH
authors.lastname: Jacobson
authors.forename: S R
authors.initials: SR
authors.lastname: Thurman-Lacey
mesh_terms: D000328:Adult; D002110:Caffeine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004361:Drug Tolerance; D005260:Female; D006801:Humans; D009048:Motor Skills / Q000187:drug effects*; D011597:Psychomotor Performance / Q000187:drug effects*; D011930:Reaction Time / Q000187:drug effects
chemical_list: D002110:Caffeine