Published in:
01-09-2015 | Original Article
Dietary nitrate improves sprint performance and cognitive function during prolonged intermittent exercise
Published in: European Journal of Applied Physiology | Issue 9/2015
Login to get accessAbstract
It is possible that dietary nitrate (NO3
−) supplementation may improve both physical and cognitive performance via its influence on blood flow and cellular energetics.
Purpose
To investigate the effects of dietary NO3
− supplementation on exercise performance and cognitive function during a prolonged intermittent sprint test (IST) protocol, which was designed to reflect typical work patterns during team sports.
Methods
In a double-blind randomised crossover study, 16 male team-sport players received NO3
−-rich (BR; 140 mL day−1; 12.8 mmol of NO3
−), and NO3
−-depleted (PL; 140 mL day−1; 0.08 mmol NO3
−) beetroot juice for 7 days. On day 7 of supplementation, subjects completed the IST (two 40-min “halves” of repeated 2-min blocks consisting of a 6-s “all-out” sprint, 100-s active recovery and 20 s of rest), on a cycle ergometer during which cognitive tasks were simultaneously performed.
Results
Total work done during the sprints of the IST was greater in BR (123 ± 19 kJ) compared to PL (119 ± 17 kJ; P < 0.05). Reaction time of response to the cognitive tasks in the second half of the IST was improved in BR compared to PL (BR first half: 820 ± 96 vs. second half: 817 ± 86 ms; PL first half: 824 ± 114 vs. second half: 847 ± 118 ms; P < 0.05). There was no difference in response accuracy.
Conclusions
These findings suggest that dietary NO3
− enhances repeated sprint performance and may attenuate the decline in cognitive function (and specifically reaction time) that may occur during prolonged intermittent exercise.