Effects of a Short-Term High-Nitrate Diet on Exercise Performance.
Study Goal
The researchers aimed to assess whether a high-nitrate diet increases nitric oxide bioavailability and improves exercise performance compared to a control diet.
Results Summary
The high-nitrate diet significantly increased plasma nitrate and nitrite concentrations, reduced oxygen consumption during moderate exercise, increased muscle work during fatiguing exercise, and improved performance in a Repeated Sprint Ability test.
Population
Seven healthy male subjects
Effective Dosage
~8.2 mmol∙day(-1) (high-nitrate diet) vs. ~2.9 mmol∙day(-1) (control diet)
Duration
6 days
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
nitrate supplementation | increase | exercise performance | - | - | can improve | #1 |
high-nitrate diet | increase | nitric oxide bioavailability | Seven healthy male subjects | - | increases | #2 |
high-nitrate diet | increase | Plasma nitrate concentrations | Seven healthy male subjects | 127 ± 64 µM vs 23 ± 10 µM | significantly higher | #3 |
high-nitrate diet | increase | Plasma nitrite concentrations | Seven healthy male subjects | 350 ± 120 nM vs 240 ± 100 nM | significantly higher | #4 |
high-nitrate diet | decrease | oxygen consumption during moderate-intensity constant work-rate cycling exercise | Seven healthy male subjects | 1.178 ± 0.141 vs. 1.269 ± 0.136 L·min(-1) | significant reduction | #5 |
high-nitrate diet | increase | total muscle work during fatiguing, intermittent sub-maximal isometric knee extension | Seven healthy male subjects | 357.3 ± 176.1 vs. 253.6 ± 149.0 Nm·s·kg(-1) | significantly higher | #6 |
high-nitrate diet | increase | performance in Repeated Sprint Ability test | Seven healthy male subjects | - | improved | #7 |
high-nitrate diet | increase | exercise performance | - | - | could be a feasible and effective strategy to improve | #8 |
It has been reported that nitrate supplementation can improve exercise performance. Most of the studies have used either beetroot juice or sodium nitrate as a supplement; there is lack of data on the potential ergogenic benefits of an increased dietary nitrate intake from a diet based on fruits and vegetables. Our aim was to assess whether a high-nitrate diet increases nitric oxide bioavailability and to evaluate the effects of this nutritional intervention on exercise performance. Seven healthy male subjects participated in a randomized cross-over study. They were tested before and after 6 days of a high (HND) or control (CD) nitrate diet (~8.2 mmol∙day(-1) or ~2.9 mmol∙day(-1), respectively). Plasma nitrate and nitrite concentrations were significantly higher in HND (127 ± 64 µM and 350 ± 120 nM, respectively) compared to CD (23 ± 10 µM and 240 ± 100 nM, respectively). In HND (vs. CD) were observed: (a) a significant reduction of oxygen consumption during moderate-intensity constant work-rate cycling exercise (1.178 ± 0.141 vs. 1.269 ± 0.136 L·min(-1)); (b) a significantly higher total muscle work during fatiguing, intermittent sub-maximal isometric knee extension (357.3 ± 176.1 vs. 253.6 ± 149.0 Nm·s·kg(-1)); (c) an improved performance in Repeated Sprint Ability test. These findings suggest that a high-nitrate diet could be a feasible and effective strategy to improve exercise performance.