Effects of a Short-Term High-Nitrate Diet on Exercise Performance

• Published in: Nutrients 2016-09, Vol.8 (9), p.534-534
• Main Authors: Porcelli, Simone, Pugliese, Lorenzo, Rejc, Enrico, Pavei, Gaspare, Bonato, Matteo, Montorsi, Michela, La Torre, Antonio, Rasica, Letizia, Marzorati, Mauro
• Format: Article
• Language: English
• Subjects: Adult; Bicycling; Bioavailability; Cross-Over Studies; Diet; Exercise; Exercise Test; Exercise Tolerance; Fruit; Healthy Diet; Humans; intermittent high-intensity exercise; Isometric Contraction; Italy; Male; Medical screening; Muscle Fatigue; Muscle Strength; Muscle, Skeletal - metabolism; Musculoskeletal system; Nitrates; Nitrates - administration & dosage; Nitrates - blood; Nitric oxide; Nitric Oxide - metabolism; Nitrites - blood; Oxygen Consumption; oxygen cost of exercise; Potassium; Sodium; Time Factors; Vegetables; Young Adult
• ISSN: 2072-6643; 2072-6643
• DOI: 10.3390/nu8090534

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.