Dietary nitrate supplementation improves sprint and high-intensity intermittent running performance
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.
Reason for embargo
The influence of dietary nitrate (NO3−) supplementation on indices of maximal sprint and intermittent exercise performance is unclear. Purpose To investigate the effects of NO3− supplementation on sprint running performance, and cognitive function and exercise performance during the sport-specific Yo-Yo Intermittent Recovery level 1 test (IR1). Methods In a double-blind, randomized, crossover study, 36 male team-sport players received NO3−-rich (BR; 70 mL·day−1; 6.4 mmol of NO3−), and NO3−-depleted (PL; 70 mL·day−1; 0.04 mmol NO3−) beetroot juice for 5 days. On day 5 of supplementation, subjects completed a series of maximal 20-m sprints followed by the Yo-Yo IR1. Cognitive tasks were completed prior to, during and immediately following the Yo-Yo IR1. Results BR improved sprint split times relative to PL at 20 m (1.2%; BR 3.98 ± 0.18 vs. PL 4.03 ± 0.19 s; P < 0.05), 10 m (1.6%; BR 2.53 ± 0.12 vs. PL 2.57 ± 0.19 s; P < 0.05) and 5 m (2.3%; BR 1.73 ± 0.09 vs. PL 1.77 ± 0.09 s; P < 0.05). The distance covered in the Yo-Yo IR1 test improved by 3.9% (BR 1422 ± 502 vs. PL 1369 ± 505 m; P < 0.05). The reaction time to the cognitive tasks was shorter in BR (615 ± 98 ms) than PL (645 ± 120 ms; P < 0.05) at rest but not during the Yo-Yo IR1. There was no difference in response accuracy. Conclusions Dietary NO3− supplementation enhances maximal sprint and high-intensity intermittent running performance in competitive team sport players. Our findings suggest that NO3− supplementation has the potential to improve performance in single-sprint or multiple-sprint (team) sports.
This work was funded by PepsiCo Inc. (2012-1891470) and both James Carter and Lara Nyman are employees of PepsiCo Inc. The views expressed in this manuscript are those of the authors and do not necessarily reflect the position or policy of PepsiCo Inc. The authors thank Ella Jackson for assistance during exercise testing. Jonathan Fulford's salary was supported via an NIHR grant.
Vol. 61, pp. 55 - 61