Effect of betaine supplementation on cycling sprint performance

Purpose: 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. © 2012 pryor et al; licensee biomed central ltd.