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Beetroot Juice Does Not Enhance Altitude Running Performance in Well-Trained Athletes

Arnold, J.T. and Oliver, S.J. and Lewis-Jones, T.M. and Wylie, L.J. and Macdonald, J.H. (2015) Beetroot Juice Does Not Enhance Altitude Running Performance in Well-Trained Athletes. Applied Physiology, Nutrition, and Metabolism. DOI: 10.1139/apnm-2014-0470

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Abstract

We hypothesized that acute dietary nitrate (NO3-) provided as concentrated beetroot juice supplement would improve endurance running performance of well-trained runners in normobaric hypoxia. Ten male runners (mean (SD): sea level V�O2max 66 (7) mL.kg<sup>-1</sup>.min<sup>-1</sup>, 10 km personal best 36 (2) min) completed incremental exercise to exhaustion at 4000 m and a 10 km treadmill time trial at 2500 m simulated altitude on separate days, after supplementation with ~7 mmol NO3- and a placebo, 2.5 h before exercise. Oxygen cost, arterial oxygen saturation, heart rate and ratings of perceived exertion (RPE) were determined during the incremental exercise test. Differences between treatments were determined using means [95% confidence intervals], paired sample t-tests and a probability of individual response analysis. NO3- supplementation increased plasma [nitrite] (NO3-, 473 (226) nM vs. placebo, 61 (37) nM, P < 0.001) but did not alter time to exhaustion during the incremental test (NO3-, 402 (80) s vs. placebo 393 (62) s, P = 0.5) or time to complete the 10 km time trial (NO3-, 2862 (233) s vs. placebo, 2874 (265) s, P = 0.6). Further, no practically meaningful beneficial effect on time trial performance was observed as the 11 [-60 to 38] s improvement was less than the a priori determined minimum important difference (51 s), and only three runners experienced a ´likely, probable´ performance improvement. NO3- also did not alter oxygen cost, arterial oxygen saturation, heart rate or RPE. Acute dietary NO3- supplementation did not consistently enhance running performance of well-trained athletes in normobaric hypoxia.

Item Type: Article
Subjects: Research Publications
Departments: College of Health and Behavioural Sciences > School of Sport, Health and Exercise Sciences
Date Deposited: 28 Feb 2015 03:40
Last Modified: 23 Sep 2015 02:49
ISSN: 1715-5312
Publisher's Statement: (c) NRC Research Press
URI: http://e.bangor.ac.uk/id/eprint/3583
Identification Number: DOI: 10.1139/apnm-2014-0470
Publisher: Canadian Science Publishing
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