Effects of Beetroot Juice Supplementation on Performance during a Repeated-Sprint Rest in Active Males
Murphy, S., Witmer, C.A., Davis, S.E., Sauers, E.J., East Stroudsburg University, East Stroudsburg, PA
Previous research has suggested that dietary nitrate (NO3-) in the form of beetroot juice may enhance particular physiological responses that result in improvement in aerobic exercise performance. Purpose: The purpose of this study was to evaluate the effects of beetroot juice on fatigue, peak power output (PPO), mean power output (MPO), delta blood lactate (ΔHLA), and oxygen uptake (VO2) during a repeated-sprint test (10 x 6 second sprints interspersed with 30 second recovery periods) in active males aged 18-24 years. Methods: Thirteen recreationally active, healthy males participated in the study. Subjects were assigned in a double-blind randomized, crossover design consuming 70 ml of beetroot juice (1 shot) containing .4-.5g of NO3- or a nitrate depleted placebo 2.5h prior to testing. A 10-day wash-out was completed during the crossover. During testing days, subjects completed a standardized warm-up followed by 10-6s repeated-sprints on a cycle ergometer interspersed with 30s passive recovery periods. Results: Statistical analysis (p≤ 0.05) found no significant difference in mean VO2, ΔHLA, PPO, MPO, and fatigue between treatments. Conclusion: In conclusion, the present study showed that there was no significant difference in fatigue during a repeated-sprint cycling test after acute supplementation with beetroot juice (~5mmol of NO3-), The researchers believe that the low acute dose of beetroot juice and/or differences in data reduction between previous studies and the current study may be possible explanations for the lack of effect on performance.
Murphy, S.; Witmer, C.A.; Davis, S.E.; and Sauers, E.J.
"Effects of Beetroot Juice Supplementation on Performance during a Repeated-Sprint Rest in Active Males,"
International Journal of Exercise Science: Conference Proceedings: Vol. 9
, Article 61.
Available at: http://digitalcommons.wku.edu/ijesab/vol9/iss2/61
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