Effects of chronic beetroot juice supplementation on maximum oxygen uptake, velocity associated with maximum oxygen uptake, and peak velocity in recreational runners: a double-blinded, randomized and crossover study

• Published in: European journal of applied physiology Vol. 119; no. 5; pp. 1043 - 1053
• Main Authors: de Castro, Talitha F., de Assis Manoel, Francisco, Figueiredo, Diogo H., Figueiredo, Diego H., Machado, Fabiana Andrade
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.05.2019; Springer Nature B.V
• Subjects: Biomedical and Life Sciences; Biomedicine; Blood levels; Body mass; Heart rate; Human Physiology; Lactic acid; Occupational Medicine/Industrial Medicine; Original Article; Oxygen; Recreation; Sports Medicine; Supplements; Velocity; Nitrate supplementation; Running; Exercise nutritional science; Physical endurance; Nitric oxide
• ISSN: 1439-6319; 1439-6327
• DOI: 10.1007/s00421-019-04094-w

Purpose This study investigated the effects of chronic 3-day beetroot juice (BRJ) supplementation on maximum oxygen uptake ( V O 2max ), velocity associated with V O 2max ( vV O 2max ), and peak velocity ( V peak ) in recreational runners. Methods Thirteen male recreational runners (age 28.2 ± 3.0 years, height 176.8 ± 0.1 cm, body mass 74.4 ± 9.5 kg) performed four tests on a treadmill in a randomized, double-blind, crossover design: two maximum incremental tests to determine V O 2max and vV O 2max, and two tests to determine V peak . Trials were performed following 3 days of supplementation of NO 3 − -rich BRJ in natura (8.4 mmol NO 3 −  day − 1 ) or BRJ NO 3 − -depleted placebo (0.01 mmol NO 3 −  day − 1 ), with the last dose being ingested 2 h before each test. During the tests, maximum heart rate (HR max ), maximal rating of perceived exertion (RPE max ), pre- and post-test glucose concentrations (Gluc pre, Gluc post ), and peak blood lactate concentration were determined. Results V O 2max was higher following BRJ vs PLA (46.6 ± 6.4 vs 45.1 ± 5.8 mL kg − 1  min − 1 ; P  = 0.022), as well as vV O 2max (14.5 ± 0.8 vs 13.9 ± 1.0 km h − 1 P  = 0.024) and V peak (15.5 ± 1.1 vs 15.2 ± 1.2 km h − 1 P  = 0.038), with no differences in the other variables. Conclusion Consumption of NO 3 − -rich BRJ in natura (8.4 mmol NO 3 −  day − 1 ) once per day for 3 days improved V O 2max , vV O 2max and V peak in recreational runners without changing the other analyzed variables.