Vol.:(0123456789) 1 3 European Journal of Applied Physiology https://doi.org/10.1007/s00421-018-3973-1 ORIGINAL ARTICLE Efect of 1-week betalain-rich beetroot concentrate supplementation on cycling performance and select physiological parameters Petey W. Mumford 1  · Wesley C. Kephart 2  · Matthew A. Romero 1  · Cody T. Haun 1  · C. Brooks Mobley 1  · Shelby C. Osburn 1  · James C. Healy 1,3  · Angelique N. Moore 3  · David D. Pascoe 1  · William C. Rufn 3  · Darren T. Beck 1,3  · Jefrey S. Martin 1,3  · Michael D. Roberts 1,3  · Kaelin C. Young 1,3 Received: 2 March 2018 / Accepted: 24 August 2018 © Springer-Verlag GmbH Germany, part of Springer Nature 2018 Abstract Purpose Betalains are indole-derived pigments found in beet root, and recent studies suggest that they may exert ergogenic efects. Herein, we examined if supplementation for 7 days with betalain-rich beetroot concentrate (BLN) improved cycling performance or altered hemodynamic and serum analytes prior to, during and following a cycling time trial (TT). Methods Twenty-eight trained male cyclists (29 ± 10 years, 77.3 ± 13.3 kg, and 3.03 ± 0.62 W/kg) performed a counterbal- anced crossover study whereby BLN (100 mg/day) or placebo (PLA) supplementation occurred over 7 days with a 1-week washout between conditions. On the morning of day seven of each supplementation condition, participants consumed one fnal serving of BLN or PLA and performed a 30-min cycling TT with concurrent assessment of several physiological vari- ables and blood markers. Results BLN supplementation improved average absolute power compared to PLA (231.6 ± 36.2 vs. 225.3 ± 35.8 W, p = 0.050, d = 0.02). Average relative power, distance traveled, blood parameters (e.g., pH, lactate, glucose, NOx) and infammatory markers (e.g., IL-6, IL-8, IL-10, TNFα) were not signifcantly diferent between conditions. BLN supplemen- tation signifcantly improved exercise efciency (W/ml/kg/min) in the last 5 min of the TT compared to PLA (p = 0.029, d = 0.45). Brachial artery blood fow in the BLN condition, immediately post-exercise, tended to be greater compared to PLA (p = 0.065, d = 0.32). Conclusions We report that 7 days of BLN supplementation modestly improves 30-min TT power output, exercise efciency as well as post-exercise blood fow without increasing plasma NOx levels or altering blood markers of infammation, oxida- tive stress, and/or hematopoiesis. Keywords Betalains · Exercise efciency · Blood fow · Cycling Abbreviations ANOVA Analysis of variance BLN Betalain-rich beetroot concentrate CO Cardiac output EPO Erythropoietin FMD Flow-mediated dilation HR Heart rate NO Nitric oxide PLA Placebo RER Respiratory exchange ratio TBARS Thiobarbituric acid reactive substances TT Time trial Introduction Beetroot contains multiple phytochemical compounds along with bioactive pigments known as betalains (Lee et al. 2005; Cliford et al. 2015). Betalains are classifed Communicated by Anni Vanhatalo. Jefrey S. Martin, Michael D. Roberts and Kaelin C. Young are co-principal investigators. * Kaelin C. Young Kyoung@auburn.vcom.edu 1 School of Kinesiology, Auburn University, Auburn, AL, USA 2 University of Wisconsin-Whitewater, Whitewater, WI, USA 3 Department of Cell Biology and Physiology, Edward Via College of Osteopathic Medicine, Auburn Campus, 910 S. Donahue Dr., Auburn, AL 36832, USA