title: The effects of creatine supplementation on selected factors of tennis specific training.
abstract: BACKGROUND
  Creatine supplementation is popular among tennis players but it is not clear whether it actually enhances tennis performance.
  
  
  OBJECTIVE
  To examine the effects of creatine supplementation on tennis specific performance indices.
  
  
  METHODS
  In a randomised, double blind design, 36 competitive male tennis players (24 creatine, mean (SD) age, 22.5 (4.9) years; 12 placebo, 22.8 (4.8) years) were tested at baseline, after six days of creatine loading, and after a maintenance phase of four weeks (14 creatine, 10 placebo). Serving velocity (10 serves), forehand and backhand velocity (three series of 5x8 strokes), arm and leg strength (bench press and leg press), and intermittent running speed (three series of five 20 metre sprints) were measured.
  
  
  RESULTS
  Compared with placebo, neither six days nor five weeks of creatine supplementation had a significant effect on serving velocity (creatine: +2 km/h; placebo: +2 km/h, p = 0.90); forehand velocity (creatine: +4 km/h; placebo: +4 km/h, p = 0.80), or backhand velocity (creatine: +3 km/h; placebo: +1 km/h, p = 0.38). There was also no significant effect of creatine supplementation on repetitive sprint power after 5, 10, and 20 metres, (creatine 20 m: -0.03 m/s; placebo 20 m: +0.01 m/s, p = 0.18), or in the strength of the upper and lower extremities.
  
  
  CONCLUSIONS
  Creatine supplementation is not effective in improving selected factors of tennis specific performance and should not be recommended to tennis players.
authors.affiliation: Royal Netherlands Lawn Tennis Association (KNLTB), Amersfoort, The Netherlands.
authors.forename: B M
authors.initials: BM
authors.lastname: Pluim
authors.forename: A
authors.initials: A
authors.lastname: Ferrauti
authors.forename: F
authors.initials: F
authors.lastname: Broekhof
authors.forename: M
authors.initials: M
authors.lastname: Deutekom
authors.forename: A
authors.initials: A
authors.lastname: Gotzmann
authors.forename: H
authors.initials: H
authors.lastname: Kuipers
authors.forename: K
authors.initials: K
authors.lastname: Weber
mesh_terms: D000293:Adolescent; D000328:Adult; D003401:Creatine / Q000008:administration & dosage*; D019587:Dietary Supplements; D004311:Double-Blind Method; D006801:Humans; D008297:Male; D013647:Task Performance and Analysis; D013715:Tennis / Q000502:physiology*; D016896:Treatment Outcome
chemical_list: D003401:Creatine