Lane, S. C, Hawley, J., Desbrow, B., Jones, A. M, Blackwell, J. R, Ross, M. L, Zemski, A. J & Burke, L. (2014). Single and combined effects of beetroot juice and caffeine supplementation on cycling time trial performance. 39(9), T. Graham. 1050-1057.: N R C Research Press. Retrieved from https://doi.org/10.1139/apnm-2013-0336
Both caffeine and beetroot juice have ergogenic effects on endurance cycling performance. We investigated whether there is an additive effect of these supplements on the performance of a cycling time trial (TT) simulating the 2012 London Olympic Games course. Twelve male and 12 female competitive cyclists each completed 4 experimental trials in a double-blind Latin square design. Trials were undertaken with a caffeinated gum (CAFF) (3 mg·kg−1 body mass (BM), 40 min prior to the TT), concentrated beetroot juice supplementation (BJ) (8.4 mmol of nitrate (NO3–), 2 h prior to the TT), caffeine plus beetroot juice (CAFF+BJ), or a control (CONT). Subjects completed the TT (females: 29.35 km; males: 43.83 km) on a laboratory cycle ergometer under conditions of best practice nutrition: following a carbohydrate-rich pre-event meal, with the ingestion of a carbohydrate–electrolyte drink and regular oral carbohydrate contact during the TT. Compared with CONT, power output was significantly enhanced after CAFF+BJ and CAFF (3.0% and 3.9%, respectively, p < 0.01). There was no effect of BJ supplementation when used alone (–0.4%, p = 0.6 compared with CONT) or when combined with caffeine (–0.9%, p = 0.4 compared with CAFF). We conclude that caffeine (3 mg·kg−1 BM) administered in the form of a caffeinated gum increased cycling TT performance lasting ∼50–60 min by ∼3%–4% in both males and females. Beetroot juice supplementation was not ergogenic under the conditions of this study.
Mary MacKillop Institute for Health Research
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