title: Ergogenic effects of betaine supplementation on strength and power performance.
abstract: BACKGROUND
  We investigated the ergogenic effects of betaine (B) supplementation on strength and power performance.
  
  
  METHODS
  Twelve men (mean +/- SD age, 21 +/- 3 yr; mass, 79.1 +/- 10.7 kg) with a minimum of 3 months resistance training completed two 14-day experimental trials separated by a 14-day washout period, in a balanced, randomized, double-blind, repeated measures, crossover design. Prior to and following 14 days of twice daily B or placebo (P) supplementation, subjects completed two consecutive days (D1 and D2) of a standardized high intensity strength/power resistance exercise challenge (REC). Performance included bench, squat, and jump tests.
  
  
  RESULTS
  Following 14-days of B supplementation, D1 and D2 bench throw power (1779 +/- 90 and 1788 +/- 34 W, respectively) and isometric bench press force (2922 +/- 297 and 2503 +/- 28 N, respectively) were increased (p < 0.05) during REC compared to pre-supplementation values (1534 +/- 30 and 1498 +/- 29 W, respectively; 2345 +/- 64 and 2423 +/- 84 N, respectively) and corresponding P values (1374 +/- 128 and 1523 +/- 39 W; 2175 +/- 92 and 2128 +/- 56 N, respectively). Compared to pre-supplementation, vertical jump power and isometric squat force increased (p < 0.05) on D1 and D2 following B supplementation. However, there were no differences in jump squat power or the number of bench press or squat repetitions.
  
  
  CONCLUSIONS
  B supplementation increased power, force and maintenance of these measures in selected performance measures, and these were more apparent in the smaller upper-body muscle groups.
authors.affiliation: Department of Kinesiology, University of Connecticut, Storrs, CT, USA. carl.maresh@uconn.edu.
authors.forename: Elaine C
authors.initials: EC
authors.lastname: Lee
authors.forename: Carl M
authors.initials: CM
authors.lastname: Maresh
authors.forename: William J
authors.initials: WJ
authors.lastname: Kraemer
authors.forename: Linda M
authors.initials: LM
authors.lastname: Yamamoto
authors.forename: Disa L
authors.initials: DL
authors.lastname: Hatfield
authors.forename: Brooke L
authors.initials: BL
authors.lastname: Bailey
authors.forename: Lawrence E
authors.initials: LE
authors.lastname: Armstrong
authors.forename: Jeff S
authors.initials: JS
authors.lastname: Volek
authors.forename: Brendon P
authors.initials: BP
authors.lastname: McDermott
authors.forename: Stuart As
authors.initials: SA
authors.lastname: Craig