title: Effect of betaine supplementation on cycling sprint performance.
abstract: OBJECTIVE
  To examine the effect of betaine supplementation on cycling sprint performance.
  
  
  METHODS
  Sixteen recreationally active subjects (7 females and 9 males) completed three sprint tests, each consisting of four 12 sec efforts against a resistance equal to 5.5% of body weight; efforts were separated by 2.5 min of cycling at zero resistance. Test one established baseline; test two and three were preceded by seven days of daily consumption of 591 ml of a carbohydrate-electrolyte beverage as a placebo or a carbohydrate-electrolyte beverage containing 0.42% betaine (approximately 2.5 grams of betaine a day); half the beverage was consumed in the morning and the other half in the afternoon. We used a double blind random order cross-over design; there was a 3 wk washout between trials two and three. Average and maximum peak and mean power were analyzed with one-way repeated measures ANOVA and, where indicated, a Student Newman-Keuls.
  
  
  RESULTS
  Compared to baseline, betaine ingestion increased average peak power (6.4%; p < 0.001), maximum peak power (5.7%; p < 0.001), average mean power (5.4%; p = 0.004), and maximum mean power (4.4%; p = 0.004) for all subjects combined. Compared to placebo, betaine ingestion significantly increased average peak power (3.4%; p = 0.026), maximum peak power max (3.8%; p = 0.007), average mean power (3.3%; p = 0.034), and maximum mean power (3.5%; p = 0.011) for all subjects combined. There were no differences between the placebo and baseline trials.
  
  
  CONCLUSIONS
  One week of betaine ingestion improved cycling sprint power in recreationally active males and females.
authors.affiliation: Department of Kinesiology, University of Connecticut, Storrs, CT 06269, U-1110, USA. john.pryor@uconn.edu.
authors.forename: J Luke
authors.initials: JL
authors.lastname: Pryor
authors.forename: Stuart As
authors.initials: SA
authors.lastname: Craig
authors.forename: Thomas
authors.initials: T
authors.lastname: Swensen