Abstract
Background: Nitric Oxide (NO), a signalling molecule and potent vasodilator linked to improved vascular function is derived from the catabolism of L-Arginine (1), and the reduction of Nitrate (NO3-) and Nitrite (NO2-) (2). The ingestion of dietary nitrate has been reported to improve exercise performance with a lower oxygen cost evident at submaximal work rates (3). Few studies have investigated the effect of dietary nitrate ingestion on short duration supra-maximal exercise performance.
Methods: Eight trained cyclists participated in a double-blind randomised cross-over study. A single 140 ml dose of concentrated beetroot juice (8 mmol NO3-) or placebo (concentrated blackcurrant juice) was ingested 2 hours prior to exercise. Participants completed five 10 s all out sprints interspersed with 30 s recovery, on a cycle ergometer. Peak and Mean power outputs (W) were recorded for all sprints. Following conformation of distribution normality (Shapiro-W-Wilk Tests), data were analysed using repeated-measures ANOVA. Wilcoxon signed rank order tests were used for post hoc analysis. Significance was established at P < 0.05 and data are expressed as mean ± SD.
Results: Peak power improved for all sprints under nitrate supplemented conditions, however only sprints one (a 3% improvement from 1144W to 1180W) and three (a 6% improvement from 872W to 933W) increased significantly (P < 0.05). Mean sprint power trended towards improved power outputs under nitrate supplemented conditions albeit without statistical significance.
Conclusions: These findings suggest a possible ergogenic effect of dietary nitrate ingestion on short duration supra-maximal repeated sprint exercise. Further research is required to confirm these findings and investigate potential mechanistic bases.
References (1)Moncada and Higgs (1993) NEJM; 329, 2002-2012(2)Larson et al. (2007) Acta Physiol; 191(1), 59-66(3)Jones (2014) Sports Med 44, S35–S45
Methods: Eight trained cyclists participated in a double-blind randomised cross-over study. A single 140 ml dose of concentrated beetroot juice (8 mmol NO3-) or placebo (concentrated blackcurrant juice) was ingested 2 hours prior to exercise. Participants completed five 10 s all out sprints interspersed with 30 s recovery, on a cycle ergometer. Peak and Mean power outputs (W) were recorded for all sprints. Following conformation of distribution normality (Shapiro-W-Wilk Tests), data were analysed using repeated-measures ANOVA. Wilcoxon signed rank order tests were used for post hoc analysis. Significance was established at P < 0.05 and data are expressed as mean ± SD.
Results: Peak power improved for all sprints under nitrate supplemented conditions, however only sprints one (a 3% improvement from 1144W to 1180W) and three (a 6% improvement from 872W to 933W) increased significantly (P < 0.05). Mean sprint power trended towards improved power outputs under nitrate supplemented conditions albeit without statistical significance.
Conclusions: These findings suggest a possible ergogenic effect of dietary nitrate ingestion on short duration supra-maximal repeated sprint exercise. Further research is required to confirm these findings and investigate potential mechanistic bases.
References (1)Moncada and Higgs (1993) NEJM; 329, 2002-2012(2)Larson et al. (2007) Acta Physiol; 191(1), 59-66(3)Jones (2014) Sports Med 44, S35–S45
| Original language | English |
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| Publication status | Published - 29 Jul 2016 |
| Event | Joint Meeting of the American Physiological Society and The Physiological Society - Convention Centre, Dublin, Ireland Duration: 29 Jul 2016 → 31 Jul 2016 |
Conference
| Conference | Joint Meeting of the American Physiological Society and The Physiological Society |
|---|---|
| Abbreviated title | Physiology 2016 |
| Country/Territory | Ireland |
| City | Dublin |
| Period | 29/07/16 → 31/07/16 |