The effect of beetroot juice supplementation on repeat-sprint performance in hypoxia. Issue 3 (1st February 2019)

• Record Type: Journal Article
• Authors: Kent, Georgina L.; Dawson, Brian; McNaughton, Lars R.; Cox, Gregory R.; Burke, Louise M.; Peeling, Peter
• Is Part Of: Journal of sports sciences. Volume 37:Issue 3(2019)
• Page Start: 339
• Page End: 346
• Publication Date: 2019-02-01
• Subjects: Dietary nitrate -- team sport -- altitude -- oxygen consumption; Sports -- Periodicals; Sports -- Physiological aspects -- Periodicals; Sports -- Psychological aspects -- Periodicals; 612.044
• DOI: 10.1080/02640414.2018.1504369
• Languages: English
• ISSNs: 0264-0414

Abstract

ABSTRACT: This investigation assessed the effect of dietary nitrate (NO3 − ) supplementation, in the form of beetroot juice (BR), on repeat-sprint performance in normoxia and normobaric hypoxia. 12 male team-sport athletes (age 22.3 ± 2.6 y, VO2peak 53.1 ± 8.7 mL.kg −1 .min −1 ) completed three exercise trials involving a 10 min submaximal warm-up and 4 sets of cycling repeat-sprint efforts (RSE; 9 × 4 s) at sea level (CON), or at 3000 m simulated altitude following acute supplementation (140 mL) with BR (HYPBR ; 13 mmol NO3 − ) or NO3 – depleted BR placebo (HYPPLA ). Peak (PPO) and mean (MPO) power output, plus work decrement were recorded during the RSE task, while oxygen consumption (VO2 ) was measured during the warm-up. There were no significant differences observed between HYPBR and HYPPLA for PPO or MPO; however, work decrement was reduced in the first RSE set in HYPBR compared with HYPPLA . There was a moderate effect for VO2 to be lower following BR at the end of the 10 min warm-up (ES = 0.50 ± 0.51). Dietary NO3 − may not improve repeat-sprint performance in hypoxia but may reduce VO2 during submaximal exercise. Therefore, BR supplementation may be more effective for performance improvement during predominantly aerobic exercise.