Lassiter, D. B., Kamer, L., Ding, Z., Burns, J., Kim, H., Lee, J., & Ivy, J. L. (2012). Even if plasma caffeine is initially elevated, energy drink consumption improves cycling performance. Presentation 2786 at the 59th Annual Meeting of the American College of Sports Medicine, San Francisco, California; May 29-June 2, 2012.

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This study compared the effects of a pre-exercise energy drink on cycling time-trial performance in trained cyclists (M = 8; F = 7) following 24 hours of caffeine abstinence. Ss received either an energy drink (containing caffeine, glucose, taurine, panax ginseng root extract, l-carnitine, caffeine, glucuronolactone, inositol, guarana seed extract, and B vitamins) or a flavor-matched placebo after 24 hours of caffeine abstinence. One hour later, Ss completed a 35-kilometer time-trial ride on a cycle ergometer. Blood was drawn and analyzed for caffeine before drink ingestion, 40 minutes later, and during the final kilometer of the time-trial. Ss whose baseline caffeine level was below 1000 ng/mL (N = 10) were categorized as low and those with baseline levels above 1000 ng/mL (N = 5) were categorized as high.

Time-to-finish improved in all Ss after receiving an energy drink when compared to placebo. Improvement in cycling performance due to the energy drink was seen in both the low and high baseline-caffeine groups.

Implication. An energy drink before aerobic exercise can enhance cycling time-trial performance even if there are high circulating levels of caffeine prior to ingestion. Improved performance despite high baseline circulating caffeine levels suggests that other ingredients contribute to the supplement’s ergogenic effect. Pre-exercise supplementation with an energy drink may benefit exercise performance when supplementation during exercise is not possible.

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